Provided by: xorriso_1.5.0-1build1_amd64 bug

NAME

       xorriso  -  creates,  loads,  manipulates  and writes ISO 9660 filesystem images with Rock
       Ridge extensions.

SYNOPSIS

       xorriso [settings|actions]

DESCRIPTION

       xorriso is a program which copies file objects from POSIX compliant filesystems into  Rock
       Ridge  enhanced  ISO  9660  filesystems  and  performs  session-wise  manipulation of such
       filesystems. It can load the management information of existing ISO images and  it  writes
       the session results to optical media or to filesystem objects.
       Vice versa xorriso is able to copy file objects out of ISO 9660 filesystems.

       A  special  property  of  xorriso  is that it needs neither an external ISO 9660 formatter
       program nor an external burn program for  CD,  DVD  or  BD  but  rather  incorporates  the
       libraries of libburnia-project.org .

   Overview of features:
       Operates on an existing ISO image or creates a new one.
       Copies files from disk filesystem into the ISO image.
       Copies files from ISO image to disk filesystem (see osirrox).
       Renames or deletes file objects in the ISO image.
       Changes file properties in the ISO image.
       Updates ISO subtrees incrementally to match given disk subtrees.
       Writes  result  either  as  completely  new image or as add-on session to optical media or
       filesystem objects.
       Can activate ISOLINUX and GRUB boot images via El Torito and MBR.
       Can perform multi-session tasks as emulation of mkisofs and cdrecord.
       Can record and restore hard links and ACL.
       Content may get zisofs compressed or filtered by external processes.
       Can issue commands to mount older sessions on GNU/Linux or FreeBSD.
       Can check media for damages and copy readable blocks to disk.
       Can attach MD5 checksums to each data file and the whole session.
       Scans for optical drives, blanks re-useable optical media.
       Reads its instructions from command line arguments, dialog, and files.
       Provides navigation commands for interactive ISO image manipulation.
       Adjustable thresholds for abort, exit value, and problem reporting.

       Note that xorriso does not write audio CDs and that it does not  produce  UDF  filesystems
       which are specified for official video DVD or BD.

   General information paragraphs:
       Session model
       Media types and states
       Creating, Growing, Modifying, Blind Growing
       Libburn drives
       Rock Ridge, POSIX, X/Open, El Torito, ACL, xattr
       Command processing
       Dialog, Readline, Result pager

       Maybe  you  first want to have a look at section EXAMPLES near the end of this text before
       reading the next few hundred lines of background information.

   Session model:
       Unlike other filesystems, ISO 9660 (aka ECMA-119) is not intended for read-write operation
       but rather for being generated in a single sweep and being written to media as a session.
       The data content of the session is called filesystem image.

       The  written  image  in  its session can then be mounted by the operating system for being
       used read-only. GNU/Linux is able to mount  ISO  images  from  block  devices,  which  may
       represent  optical  media,  other media or via a loop device even from regular disk files.
       FreeBSD mounts ISO images from devices that represent arbitrary media or from regular disk
       files.

       This  session  usage model has been extended on CD media by the concept of multi-session ,
       which adds information to the CD and gives the mount programs of the operating systems the
       addresses  of the entry points of each session. The mount programs recognize block devices
       which represent CD media and will by default mount the image in the last session.
       This session usually contains an updated directory tree for the whole medium which governs
       the  data  contents  in  all  recorded  sessions.  So in the view of the mount program all
       sessions of a particular medium together form a single filesystem image.
       Adding a session to an existing ISO image is in this text referred as growing.
       The multi-session model of the MMC standard does not apply to all media types. But program
       growisofs  by Andy Polyakov showed how to extend this functionality to overwriteable media
       or disk files which carry valid ISO 9660 filesystems.

       xorriso provides growing as well as  an  own  method  named  modifying  which  produces  a
       completely  new ISO image from the old one and the modifications.  See paragraph Creating,
       Growing, Modifying, Blind Growing below.

       xorriso adopts the concept of multi-session by loading an image directory tree if present,
       by  offering  to  manipulate  it  by  several actions, and by writing the new image to the
       target medium.
       The first session of a xorriso run begins by the definition of the input  drive  with  the
       ISO  image  or  by the definition of an output drive.  The session ends by command -commit
       which triggers writing. A -commit is done automatically when the program ends regularly.

       After -commit a new session begins with the freshly written one as  input.   A  new  input
       drive  can  only  be  chosen  as  long  as  the  loaded ISO image was not altered. Pending
       alteration can be revoked by command -rollback.

       Writing a session to the target is supposed to be very expensive in terms of time  and  of
       consumed  space on appendable or write-once media. Therefore all intended manipulations of
       a particular ISO image should be done in a single session. But in principle it is possible
       to store intermediate states and to continue with image manipulations.

   Media types and states:
       There are two families of media in the MMC standard:
       Multi-session media are CD-R, CD-RW, DVD-R, DVD+R, DVD+R/DL, BD-R, and unformatted DVD-RW.
       These media provide a table of  content  which  describes  their  existing  sessions.  See
       command -toc.
       Similar  to  multi-session  media  are DVD-R DL and minimally blanked DVD-RW.  They record
       only a single session of which the size must be known in advance.  xorriso will write onto
       them only if command -close is set to "on".
       Overwriteable  media  are DVD-RAM, DVD+RW, BD-RE, and formatted DVD-RW.  They offer random
       write access but do not provide information about their session history. If  they  contain
       one  or  more  ISO  9660  sessions and if the first session was written by xorriso, then a
       table of content can be emulated. Else only a single overall session will be visible.
       DVD-RW media can be formatted by -format "full".  They can be made unformatted  by  -blank
       "deformat".
       Regular  files  and  block  devices  are  handled as overwriteable media.  Pipes and other
       writeable file types are handled as blank multi-session media.

       These media can assume several states in which they offer different capabilities.
       Blank media can be written from scratch. They contain no ISO image suitable for xorriso.
       Blank is the state of newly purchased optical media.  With used CD-RW and DVD-RW it can be
       achieved  by  action -blank "as_needed".  Overwriteable media are considered blank if they
       are new or if they have been marked as blank by xorriso.  Action -blank "as_needed" can be
       used  to  do  this marking on overwriteable media, or to apply mandatory formatting to new
       media if necessary.
       Appendable media accept further sessions. Either  they  are  MMC  multi-session  media  in
       appendable  state, or they are overwriteable media which contain an ISO image suitable for
       xorriso.
       Appendable is the state after writing a session with command -close off.
       Closed media cannot be written. They may contain an ISO image suitable for xorriso.
       Closed is the state of DVD-ROM media and of multi-session media which  were  written  with
       command -close on. If the drive is read-only hardware then it will probably show any media
       as closed CD-ROM or DVD-ROM.
       Overwriteable media assume this  state  in  such  read-only  drives  or  if  they  contain
       unrecognizable data in the first 32 data blocks.
       Read-only  drives may or may not show session histories of multi-session media. Often only
       the first and the last session are visible. Sometimes not even that. Command -rom_toc_scan
       might or might not help in such cases.

   Creating, Growing, Modifying, Blind Growing:
       A  new empty ISO image gets created if there is no input drive with a valid ISO 9660 image
       when the first time an output drive is defined. This is achieved by command -dev on  blank
       media or by command -outdev on media in any state.
       The  new  empty  image  can  be  populated  with  directories and files.  Before it can be
       written, the medium in the output drive must get into blank state  if  it  was  not  blank
       already.

       If  there  is  a  input  drive  with  a  valid  ISO  image, then this image gets loaded as
       foundation for manipulations and extension. The constellation of input  and  output  drive
       determines  which  write  method will be used.  They have quite different capabilities and
       constraints.

       The method of growing adds new data to  the  existing  data  on  the  medium.  These  data
       comprise  of  new  file  content  and  they  override  the  existing ISO 9660 + Rock Ridge
       directory tree. It is possible to hide files from previous sessions but they  still  exist
       on  the  medium  and  with many types of optical media it is quite easy to recover them by
       mounting older sessions.
       Growing is achieved by command -dev.

       The write method of modifying produces compact filesystem images with no outdated files or
       directory  trees.  Modifying  can  write  its  images to target media which are completely
       unsuitable for multi-session operations.  E.g.  DVD-RW  which  were  treated  with  -blank
       deformat_quickest,  DVD-R  DL, named pipes, character devices, sockets.  On the other hand
       modified sessions cannot be written to appendable media but to blank media only.
       So for this method one needs either two optical drives or  has  to  work  with  filesystem
       objects as source and/or target medium.
       Modifying  takes  place  if  input  drive and output drive are not the same and if command
       -grow_blindly is set to its default "off".   This  is  achieved  by  commands  -indev  and
       -outdev.

       If  command  -grow_blindly  is  set to a non-negative number and if -indev and -outdev are
       both set to different drives, then blind growing  is  performed.  It  produces  an  add-on
       session  which  is  ready  for being written to the given block address. This is the usage
       model of
        mkisofs -M $indev -C $msc1,$msc2 -o $outdev
       which gives much room for wrong parameter combinations and should thus only be employed if
       a  strict  distinction  between  ISO formatter xorriso and the burn program is desired. -C
       $msc1,$msc2 is equivalent to:
        -load sbsector $msc1 -grow_blindly $msc2

   Libburn drives:
       Input drive, i.e. source of an existing or empty ISO  image,  can  be  any  random  access
       readable  libburn  drive:  optical  media with readable data, blank optical media, regular
       files, block devices.
       Output drive, i.e. target for writing, can be any libburn drive.  Some drive types do  not
       support  the  method  of growing but only the methods of modifying and blind growing. They
       all are suitable for newly created images.

       All drive file objects have to offer rw-permission to the user  of  xorriso.   Even  those
       which will not be useable for reading an ISO image.
       With any type of drive object, the data are considered to be organized in blocks of 2 KiB.
       Access happens in terms of Logical Block  Address  (LBA)  which  gives  the  number  of  a
       particular data block.

       MMC  compliant  (i.e.  optical)  drives  on GNU/Linux usually get addressed by the path of
       their block device or of their generic character device. E.g.
         -dev /dev/sr0
         -dev /dev/hdc
         -dev /dev/sg2
       By default xorriso will try to map the  given  address  to  /dev/hd*  and  /dev/sr*.   The
       command  -scsi_dev_family  can redirect the mapping from sr to scd or sg.  The latter does
       not suffer from the concurrency problems which  plague  /dev/sr  of  Linux  kernels  since
       version  3.  But  it  does  not  yield the same addresses which are used by mount(8) or by
       open(2) for read(2).
       On FreeBSD the device files have names like
         -dev /dev/cd0
       On NetBSD:
         -dev /dev/rcd0d
       On OpenSolaris:
         -dev /dev/rdsk/c4t0d0s2
       Get a list of accessible drives by command
         -device_links
       It might be necessary to do this as superuser in order to see all drives and to then allow
       rw-access for the intended users.  Consider to bundle the authorized users in a group like
       old "floppy".

       Filesystem objects of nearly any type can be addressed by prefix "stdio:" and  their  path
       in the filesystem. E.g.:
         -dev stdio:/dev/sdc
       The default setting of -drive_class allows the user to address files outside the /dev tree
       without that prefix. E.g.:
         -dev /tmp/pseudo_drive
       If path leads to a regular file or to a block device then the  emulated  drive  is  random
       access  readable  and can be used for the method of growing if it already contains a valid
       ISO 9660 image. Any other file type is not readable via "stdio:" and can only be  used  as
       target  for  the  method  of  modifying  or blind growing.  Non-existing paths in existing
       directories are handled as empty regular files.

       A very special kind of pseudo drive are  open  file  descriptors.  They  are  depicted  by
       "stdio:/dev/fd/" and descriptor number (see man 2 open).
       Addresses  "-"  or  "stdio:/dev/fd/1" depict standard output, which normally is the output
       channel for result texts.  To  prevent  a  fatal  intermingling  of  ISO  image  and  text
       messages,  all  result texts get redirected to stderr if -*dev "-" or "stdio:/dev/fd/1" is
       among the start arguments of the program.
       Standard output is currently suitable for creating one session  per  program  run  without
       dialog. Use in other situations is discouraged and several restrictions apply:
       It  is  not  allowed  to use standard output as pseudo drive if it was not among the start
       arguments. Do not try to fool this ban via backdoor addresses to stdout.
       If stdout is used as drive, then -use_readline is permanently disabled.  Use of  backdoors
       can cause severe memory and/or tty corruption.

       Be  aware  that  especially  the superuser can write into any accessible file or device by
       using its path with the "stdio:" prefix. By default any address in the /dev  tree  without
       prefix "stdio:" will work only if it leads to a MMC drive.
       One  may  use  command  -ban_stdio_write to surely prevent this risk and to restrict drive
       usage to MMC drives.
       One may prepend "mmc:" to a path to surely disallow any automatic "stdio:".
       By command -drive_class one may ban certain paths or allow access without prefix  "stdio:"
       to other paths.

   Rock Ridge, POSIX, X/Open, El Torito, ACL, xattr:
       Rock  Ridge  is  the  name  of  a  set of additional information which enhance an ISO 9660
       filesystem so that it can represent a POSIX compliant filesystem  with  ownership,  access
       permissions, symbolic links, and other attributes.
       This  is  what  xorriso  uses for a decent representation of the disk files within the ISO
       image. xorriso produces Rock Ridge information by default. It is strongly  discouraged  to
       disable this feature.

       xorriso  is  not  named  "porriso" because POSIX only guarantees 14 characters of filename
       length. It is the X/Open System Interface standard XSI which demands a file name length of
       up to 255 characters and paths of up to 1024 characters. Rock Ridge fulfills this demand.

       An  El  Torito  boot  record  points  the  BIOS bootstrapping facility to one or more boot
       images, which are binary program files stored in the ISO image.  The content of  the  boot
       image files is not in the scope of El Torito.
       Most  bootable  GNU/Linux  CDs are equipped with ISOLINUX or GRUB boot images.  xorriso is
       able to create or maintain an El Torito object which makes such  an  image  bootable.  For
       details see command -boot_image.
       It  is  possible to make ISO images bootable from USB stick or other hard-disk-like media.
       Several options install a MBR (Master Boot Record), It may get adjusted according  to  the
       needs of the intended boot firmware and the involved boot loaders, e.g. GRUB2 or ISOLINUX.
       A MBR contains boot code and a partition table.  The new MBR of a  follow-up  session  can
       get in effect only on overwriteable media.
       MBR  is  read  by PC-BIOS when booting from USB stick or hard disk, and by PowerPC CHRP or
       PReP when booting.  An MBR partition with type 0xee indicates the presence of GPT.
       Emulation -as mkisofs supports the example options out of the ISOLINUX wiki,  the  options
       used in GRUB script grub-mkrescue, and the example in the FreeBSD AvgLiveCD wiki.
       A  GPT  (GUID  Partition  Table) marks partitions in a more modern way.  It is read by EFI
       when booting from USB stick or hard disk, and may be used for finding and mounting a  HFS+
       partition inside the ISO image.
       An APM (Apple Partition Map) marks the HFS+ partition.  It is read by Macs for booting and
       for mounting.
       MBR, GPT and APM are combinable. APM occupies the first 8 bytes  of  MBR  boot  code.  All
       three do not hamper El Torito booting from CDROM.
       There  is support for further facilities: MIPS Big Endian (SGI), MIPS Little Endian (DEC),
       SUN SPARC, HP-PA.  Those are mutually not combinable and also  not  combinable  with  MBR,
       GPT, or APM.

       ACL  are  an  advanced  way of controlling access permissions to file objects. Neither ISO
       9660 nor Rock Ridge specify a way to record ACLs. So libisofs has  introduced  a  standard
       conformant  extension  named  AAIP for that purpose.  It uses this extension if enabled by
       command -acl.
       AAIP enhanced images are supposed to be mountable normally, but one cannot expect that the
       mounted  filesystem  will  show  and  respect  the ACLs.  For now, only xorriso is able to
       retrieve those ACLs.  It can bring them into effect when files  get  restored  to  an  ACL
       enabled file system or it can print them in a format suitable for tool setfacl.
       Files  with  ACL  show  as  group  permissions the setting of entry "mask::" if that entry
       exists.  Nevertheless  the  non-listed  group  members  get  handled  according  to  entry
       "group::". When removing ACL from a file, xorriso brings "group::" into effect.
       Recording  and restoring of ACLs from and to local files works currently only on GNU/Linux
       and FreeBSD.

       xattr (aka EA, or extattr) are pairs of name and value  which  can  be  attached  to  file
       objects. AAIP is able to represent them and xorriso can record and restore them.
       But  be  aware  that  pairs with names of non-user namespaces are not necessarily portable
       between operating systems and not even between filesystems.  Only those which  begin  with
       "user.",  like  "user.x"  or  "user.whatever",  can  unconditionally  be  expected  to  be
       appropriate on other machines and disks.  Processing of other xattr may need administrator
       privileges.
       Name  has  to  be  a  0 terminated string.  Value may be any array of bytes which does not
       exceed the size of 4095 bytes.  xattr processing happens only if it is enabled by  command
       -xattr.
       As  with  ACL, currently only xorriso is able to retrieve xattr from AAIP enhanced images,
       to restore them to xattr capable file systems, or to print them.
       Recording and restoring of xattr from and to local files works currently only on GNU/Linux
       and FreeBSD, where they are known as extattr.

   Command processing:
       Commands are either actions which happen immediately or settings which influence following
       actions. So their sequence does matter, unless they are given  as  program  arguments  and
       command -x is among them.
       Commands  consist of a command word, followed by zero or more parameter words. If the list
       of parameter words is of variable length (indicated by "[...]" or "[***]") then it must be
       terminated  by  either the list delimiter, occur at the end of the argument list, or occur
       at the end of an input line.

       At program start the list delimiter is the string "--".  This  may  be  changed  with  the
       -list_delimiter  command  in  order  to allow "--" as parameter in a variable length list.
       However, it is advised to reset the delimiter to "--" immediately afterwards.
       For brevity the list delimiter is referred as "--" throughout this text.
       The list delimiter is silently ignored if it appears after the  parameters  of  a  command
       with  a fixed list length. It is handled as normal text if it appears among the parameters
       of such a command.

       Pattern expansion converts a list of pattern words into a list of existing file addresses.
       Unmatched pattern words will appear unaltered in that result list.
       Pattern  matching  supports  the usual shell parser wildcards '*' '?' '[xyz]' and respects
       '/' as the path separator, which may only be matched literally.
       Pattern expansion is a property of some particular commands and not a general feature.  It
       is  controlled  by commands -iso_rr_pattern and -disk_pattern.  Commands which use pattern
       expansion all have variable parameter lists which are specified in this  text  by  "[***]"
       rather than "[...]".
       Some other commands perform pattern matching unconditionally.

       Command and parameter words are either read from the program arguments, where one argument
       is one word, or from quoted  input  lines  where  words  are  recognized  similar  to  the
       quotation rules of a shell parser.
       xorriso  is  not a shell, although it might appear so at first glimpse.  Be aware that the
       interaction of quotation marks and pattern symbols like "*" differs from the  usual  shell
       parsers. In xorriso, a quotation mark does not make a pattern symbol literal.

       Quoted  input  converts whitespace-separated text into words.  The double quotation mark "
       and the single quotation mark ' can be used to enclose whitespace  and  make  it  part  of
       words  (e.g.  of  file  names).  Each mark type can enclose the marks of the other type. A
       trailing backslash \ outside quotations or an open quotation cause the next input line  to
       be appended.
       Quoted  input  accepts  any  8-bit  character except NUL (0) as the content of the quotes.
       Nevertheless it can be cumbersome for the  user  to  produce  those  characters  directly.
       Therefore quoted input and program arguments offer optional Backslash Interpretation which
       can represent all 8-bit characters except NUL (0) via backslash  codes  as  in  $'...'  of
       bash.
       This is not enabled by default. See command -backslash_codes.

       When  the  program  starts then it first looks for argument -no_rc. If this is not present
       then it looks for its startup files and reads their content as command input  lines.  Then
       it  interprets  the program arguments as commands and parameters. Finally it enters dialog
       mode if command -dialog "on" has been executed by this point.

       The program ends either by command -end, or by the end of program arguments if dialog mode
       has  not been enabled at that point, or by a problem event which triggers the threshold of
       command -abort_on.

   Dialog, Readline, Result pager:
       Dialog mode prompts for a quoted input line, parses it into words, and  performs  them  as
       commands  with  their  parameters.  It  provides  assisting  services  to make dialog more
       comfortable.

       Readline is an enhancement for the input line. You may  already  know  it  from  the  bash
       shell.  Whether  it  is  available  in  xorriso  depends  on  the  availability of package
       readline-dev at the time when xorriso was built from its sourcecode.
       Readline lets the user move the cursor over the text in the line by help of the  Left  and
       the Right arrow keys.  Text may be inserted at the cursor position. The Delete key removes
       the character under the cursor. Up and Down arrow keys navigate  through  the  history  of
       previous input lines.
       See man readline for more info about libreadline.

       Command  -page  activates  a  built-in result text pager which may be convenient in dialog
       mode. After an action has output the given number of terminal lines, the pager prompts the
       user for a line of input.
       An empty line lets xorriso resume work until the next page is output.
       The single character "@" disables paging for the current action.
       "@@@",  "x",  "q", "X", or "Q" request that the current action aborts and suppress further
       result output.
       Any other line input will be interpreted  as  new  dialog  line.  The  current  action  is
       requested to abort. Afterwards, the input line is executed.

       Some actions apply paging to their info output, too.
       The  request  to abort may or may not be obeyed by the current action.  All actions try to
       abort as soon as possible.

OPTIONS

       All command words are shown with a leading dash although this dash is  not  mandatory  for
       the  command  to be recognized. Nevertheless within command -as the dashes of the emulated
       commands are mandatory.
       Normally any number of leading dashes is ignored with command words and inner  dashes  are
       interpreted as underscores.

       Execution order of program arguments:

       By  default  the  program  arguments  of  a  xorriso  run are interpreted as a sequence of
       commands which get performed exactly in the given order.  This requires the user to  write
       commands  for  desired  settings  before  the  commands which shall be influenced by those
       settings.
       Many other programs support  program  arguments  in  an  arbitrary  ordering  and  perform
       settings and actions in a sequence at their own discretion.  xorriso provides an option to
       enable such a behavior at the cost of loss of expressivity.

       -x     Enable automatic sorting of program arguments into a sequence that (most likely) is
              sensible.   This  command may be given at any position among the commands which are
              handed over as program arguments.
              Note: It works only if it is given as program argument and with a single dash (i.e.
              "-x").  It  will  not  work  in  startup files, nor with -options_from_file, nor in
              dialog mode, nor as "x" and finally not as "--x".  It  affects  only  the  commands
              given as program arguments.

       -list_arg_sorting
              List all xorriso commands in the order which applies if command -x is in effect.
              This  list  may also be helpful without -x for a user who ponders over the sequence
              in which to put commands. Deviations from the listed sorting order  may  well  make
              sense, though.

       Acquiring source and target drive:

       The  effect  of  acquiring  a  drive  may depend on several commands in the next paragraph
       "Influencing the behavior of image loading".  If desired, their enabling commands have  to
       be performed before the commands which acquire the drive.

       -dev address
              Set  input  and  output  drive  to  the same address and load an ISO image if it is
              present.  If there is no ISO  image  then  create  a  blank  one.   Set  the  image
              expansion method to growing.
              This  is only allowed as long as no changes are pending in the currently loaded ISO
              image. If changes are pending, then one has to perform -commit or -rollback first.
              Special address string "-" means standard output,  to  which  several  restrictions
              apply. See above paragraph "Libburn drives".
              An empty address string "" gives up the current device without acquiring a new one.

       -indev address
              Set  input  drive and load an ISO image if present.  If the new input drive differs
              from -outdev then switch from growing to modifying or to blind growing.  It depends
              on  the  setting of -grow_blindly which of both gets activated.  The same rules and
              restrictions apply as with -dev.

       -outdev address
              Set output drive and if it differs from the input drive then switch from growing to
              modifying  or  to blind growing. Unlike -dev and -indev this action does not load a
              new ISO image. So it can be performed even if there are pending changes.
              -outdev can be performed without previous -dev or -indev. In that case an empty ISO
              image  with  no  changes  pending is created. It can either be populated by help of
              -map, -add et.al. or it can be discarded silently if -dev or -indev  are  performed
              afterwards.
              Special  address  string  "-"  means standard output, to which several restrictions
              apply. See above paragraph "Libburn drives".
              An empty address string "" gives up the current output drive  without  acquiring  a
              new one. No writing is possible without an output drive.

       -scsi_dev_family "default"|"sr"|"scd"|"sg"
              GNU/Linux specific:
              By  default, xorriso tries to map Linux drive addresses to /dev/sr* before they get
              opened for operating the drive. This coordinates  well  with  other  use  cases  of
              optical drives, like mount(8). But since year 2010 all /dev/sr* share a global lock
              which allows only one drive to process an SCSI command while  all  others  have  to
              wait  for  its  completion.  This yields awful throughput if more than one drive is
              writing or reading simultaneously.  The global lock is not applied to device  files
              /dev/sg* and also not if the xorriso drive address is prepended by "stdio:".
              So  for  simultaneous  burn  runs  on  modern  GNU/Linux it is advisable to perform
              -scsi_dev_family "sg" before any -dev, -indev, or -outdev. The drive addresses  may
              then  well  be  given  as  /dev/sr*  but will nevertheless get used as the matching
              /dev/sg*.
              If you decide so, consider to put the command  into  a  global  startup  file  like
              /etc/opt/xorriso/rc.

       -grow_blindly "off"|predicted_nwa
              If  predicted_nwa  is  a non-negative number then perform blind growing rather than
              modifying if -indev and -outdev are set to different drives.  "off" or "-1"  switch
              to modifying, which is the default.
              predicted_nwa  is  the block address where the add-on session of blind growing will
              finally end up. It is the responsibility of the user to ensure this final  position
              and  the  presence  of  the  older sessions. Else the overall ISO image will not be
              mountable or will produce read errors when accessing  file  content.  xorriso  will
              write  the  session  to  the  address  as  obtained  from examining -outdev and not
              necessarily to predicted_nwa.
              During a run of blind growing, the input drive is given up  before  output  begins.
              The output drive is given up when writing is done.

       Influencing the behavior of image loading:

       The  following  commands should normally be performed before loading an image by acquiring
       an input drive. In rare cases it is desirable to activate them only after image loading.

       -read_speed code|number[k|m|c|d|b]
              Set the speed for reading. Default is "none", which avoids to send a speed  setting
              command to the drive before reading begins.
              Further special speed codes are:
              "max" (or "0") selects maximum speed as announced by the drive.
              "min" (or "-1") selects minimum speed as announced by the drive.
              Speed can be given in media dependent numbers or as a desired throughput per second
              in MMC compliant kB (= 1000) or MB (= 1000 kB). Media x-speed  factor  can  be  set
              explicitly by "c" for CD, "d" for DVD, "b" for BD, "x" is optional.
              Example speeds:
               706k = 706kB/s = 4c = 4xCD
               5540k = 5540kB/s = 4d = 4xDVD
              If  there  is  no hint about the speed unit attached, then the medium in the -indev
              will decide. Default unit is CD = 176.4k.
              Depending on the drive, the reported read speeds can be deceivingly  low  or  high.
              Therefore  "min"  cannot  become  higher than 1x speed of the involved medium type.
              Read speed "max" cannot become lower than 52xCD, 24xDVD, or 20xBD, depending on the
              medium type.
              MMC  drives usually activate their own idea of speed and take the speed value given
              by the burn program only as hint for their own decision.

       -load entity id
              Load a particular (possibly outdated) ISO session from -dev or -indev.  Usually all
              available sessions are shown with command -toc.
              entity  depicts  the  kind  of  addressing.  id depicts the particular address. The
              following entities are defined:
              "auto" with any id addresses the last session in -toc. This is the default.
              "session" with id being a number as of a line "ISO session", column "Idx".
              "track" with id being a number as of a line "ISO track", column "Idx".
              "lba" or "sbsector" with a number as of a line "ISO ...", column "sbsector".
              "volid" with a search pattern for a text as of a line  "ISO  ...",  column  "Volume
              Id".
              Addressing  a non-existing entity or one which does not represent an ISO image will
              either abandon -indev or at least lead to a blank image.
              If an input drive is set at the moment when -load is executed, then  the  addressed
              ISO  image  is loaded immediately. Else, the setting will be pending until the next
              -dev or -indev. After the image has been loaded once,  the  setting  is  valid  for
              -rollback until next -dev or -indev, where it will be reset to "auto".

       -displacement [-]lba
              Compensate a displacement of the image versus the start address for which the image
              was prepared. This affects only loading of ISO images and reading of  their  files.
              The  multi-session  method  of  growing  is not allowed as long as -displacement is
              non-zero. I.e. -indev and -outdev must be different. The displacement gets reset to
              0 before the drive gets re-acquired after writing.
              Examples:
              If  a  track of a CD starts at block 123456 and gets copied to a disk file where it
              begins at block 0, then this copy can be loaded with
                -displacement -123456
              If an ISO image was written onto a partition with offset of 640000  blocks  of  512
              bytes, then it can be loaded from the base device by
                -load sbsector 160000 -displacement 160000
              (If the partition start address is not divisible by 4, then you will have to employ
              a loop device instead.)
              In both cases, the ISO sessions should be self contained, i.e. not add-on  sessions
              to an ISO image outside their track or partition.

       -drive_class "harmless"|"banned"|"caution"|"clear_list" disk_pattern
              Add  a  drive  path  pattern  to one of the safety lists or make those lists empty.
              There are three lists defined which get tested in the following sequence:
              If a drive address path  matches  the  "harmless"  list  then  the  drive  will  be
              accepted.  If  it  is  not  a MMC device then the prefix "stdio:" will be prepended
              automatically. This list is empty by default.
              Else if the path matches the "banned" list then the drive will not be  accepted  by
              xorriso but rather lead to a FAILURE event.  This list is empty by default.
              Else if the path matches the "caution" list and if it is not a MMC device, then its
              address must have the prefix "stdio:" or it will be rejected.   This  list  has  by
              default one entry: "/dev".
              If  a drive path matches no list then it is considered "harmless". By default these
              are all paths which do not begin with directory "/dev".
              A path matches a list if one of its parent paths or itself matches  a  list  entry.
              Address prefix "stdio:" or "mmc:" will be ignored when testing for matches.
              By  pseudo-class  "clear_list" and pseudo-patterns "banned", "caution", "harmless",
              or "all", the lists may be made empty.
              E.g.: -drive_class clear_list banned
              One will normally define the -drive_class lists  in  one  of  the  xorriso  Startup
              Files.
              Note:  This  is  not  a  security  feature but rather a bumper for the superuser to
              prevent inadverted mishaps. For reliably blocking access to a device file you  have
              to deny its rw-permissions in the filesystem.

       -read_fs "any"|"norock"|"nojoliet"|"ecma119"
              Specify  which  kind  of  filesystem tree to load if present. If the wish cannot be
              fulfilled, then ECMA-119 names are loaded and converted according to -ecma119_map.
              "any" first tries to read Rock Ridge. If not present, Joliet is tried.
              "norock" does not try Rock Ridge.
              "nojoliet" does not try Joliet.
              "ecma119" tries neither Rock Ridge nor Joliet.

       -assert_volid pattern severity
              Refuse to load ISO images with volume IDs which  do  not  match  the  given  search
              pattern.  When refusing an image, give up the input drive and issue an event of the
              given severity (like FAILURE, see -abort_on). An empty search pattern  accepts  any
              image.
              This  command does not hamper the creation of an empty image from blank input media
              and does not discard an already loaded image.

       -in_charset character_set_name
              Set the character set from which to convert file names when loading an  image.  See
              paragraph  "Character  sets" for more explanations.  When loading the written image
              after -commit the setting of -out_charset will be copied to -in_charset.

       -auto_charset "on"|"off"
              Enable or disable recording and interpretation of the output character set name  in
              an  xattr  attribute  of  the  image  root  directory. If enabled and if a recorded
              character set name is found, then this name will be  used  as  name  of  the  input
              character set when reading an image.
              Note  that  the  default  output charset is the local character set of the terminal
              where xorriso runs. Before attributing this local character set to the produced ISO
              image,  check  whether  the  terminal  properly  displays  all  intended filenames,
              especially exotic national characters.

       -hardlinks mode[:mode...]
              Enable or disable loading and recording of hardlink relations.
              In default mode "off", iso_rr files lose their inode numbers at  image  load  time.
              Each iso_rr file object which has no inode number at image generation time will get
              a new unique inode number if -compliance is set to new_rr.
              Mode "on" preserves inode numbers from  the  loaded  image  if  such  numbers  were
              recorded.  When committing a session it searches for families of iso_rr files which
              stem from the same disk file, have identical content filtering and  have  identical
              properties.  The  family  members  all  get  the  same inode number.  Whether these
              numbers are respected at mount time depends on the operating system.
              Command -lsl displays hardlink counts if "lsl_count" is enabled. This can slow down
              the  command substantially after changes to the ISO image have been made. Therefore
              the default is "no_lsl_count".
              Commands  -update  and  -update_r  track  splits  and  fusions  of  hard  links  in
              filesystems  which  have  stable device and inode numbers. This can cause automatic
              last  minute  changes  before  the  session  gets   written.   Command   -hardlinks
              "perform_update" may be used to do these changes earlier, e.g. if you need to apply
              filters to all updated files.
              Mode "without_update" avoids hardlink processing during update commands.  Use  this
              if your filesystem situation does not allow -disk_dev_ino "on".
              xorriso  commands  which extract files from an ISO image try to hardlink files with
              identical inode number. The normal scope of this operation is from  image  load  to
              image  load.  One  may  give  up  the accumulated hard link addresses by -hardlinks
              "discard_extract".
              A large number of hardlink families may exhaust  -temp_mem_limit  if  not  -osirrox
              "sort_lba_on"  and  -hardlinks  "cheap_sorted_extract"  are  both  in  effect. This
              restricts hard linking to other files restored by the same single extract  command.
              -hardlinks "normal_extract" re-enables wide and expensive hardlink accumulation.

       -acl "on"|"off"
              Enable  or  disable  processing of ACLs.  If enabled, then xorriso will obtain ACLs
              from disk file objects, store ACLs in the ISO image  using  the  libisofs  specific
              AAIP  format,  load AAIP data from ISO images, test ACL during file comparison, and
              restore ACLs to disk files when extracting them from ISO images.  See also commands
              -getfacl, -setfacl.

       -xattr "on"|"user"|"any"|"off"
              Enable  or  disable  processing of xattr attributes.  If enabled, then xorriso will
              handle xattr similar to ACL.  See also  commands  -getfattr,  -setfattr  and  above
              paragraph about xattr.
              Modes "on" and "user" read and write only attributes from namespace "user".
              Mode  "any"  processes  attributes  of all namespaces. This might need adminstrator
              privileges, even if the owner  of  the  disk  file  tries  to  read  or  write  the
              attributes.
              Note  that  xattr  from  namespace "isofs." are never read from disk or restored to
              disk. Further it is not  possible  to  set  them  via  xorriso  xattr  manipulation
              commands.

       -md5 "on"|"all"|"off"|"load_check_off"
              Enable  or disable processing of MD5 checksums for the overall session and for each
              single data file. If enabled then images with checksum tags get loaded only if  the
              tags  of  superblock  and  directory tree match properly. The MD5 checksums of data
              files and whole session get loaded from the image if there are any.
              With commands -compare and -update the recorded MD5 of a file will be used to avoid
              content  reading  from  the  image.  Only  the  disk  file content will be read and
              compared with that MD5. This can save  much  time  if  -disk_dev_ino  "on"  is  not
              suitable.
              At  image  generation  time  they  are  computed  for each file which gets its data
              written into the new session. The checksums of files which have their data in older
              sessions  get copied into the new session. Superblock, tree and whole session get a
              checksum tag each.
              Mode "all" will additionally check during image generation whether the checksum  of
              a  data  file  changed between the time when its reading began and the time when it
              ended. This implies reading every file twice.
              Mode "load_check_off" together with "on" or "all" will load recorded MD5  sums  but
              not  test  the  recorded  checksum  tags of superblock and directory tree.  This is
              necessary if growisofs was used as burn program, because it does not overwrite  the
              superblock  checksum  tag  of  the  first  session.  Therefore load_check_off is in
              effect when xorriso -as mkisofs option -M is performed.
              The test can be re-enabled by mode "load_check_on".
              Checksums can be exploited via commands -check_md5, -check_md5_r, via find  actions
              get_md5, check_md5, and via -check_media.

       -for_backup
              Enable  all extra features which help to produce or to restore backups with highest
              fidelity of file properties. Currently this is a shortcut for:
              -hardlinks on -acl on -xattr any -md5 on
              If you restore a backup with xattr from non-user namespaces, then  make  sure  that
              the  target  operating  system  and  filesystem  know  what  these attributes mean.
              Possibly  you  will  need  administrator  privileges  to  record  or  restore  such
              attributes.  At recording time, xorriso will try to tolerate missing privileges and
              just record what is readable.  But at restore time, missing privileges  will  cause
              failure events.
              Command  -xattr  "user" after command -for_backup excludes non-user attributes from
              being recorded or restored.

       -ecma119_map "stripped"|"unmapped"|"lowercase"|"uppercase"
              Choose the conversion of file names from the loaded session if neither a Rock Ridge
              name nor a Joliet name was read from the session.
              Mode  "stripped" is the default. It shows the names as found in the ISO but removes
              trailing ";1" or ".;1" if present.
              Mode "unmapped" shows names as found without removing characters.
              Mode "lowercase" is like "stripped" but also maps uppercase  letters  to  lowercase
              letters. This is compatible to default GNU/Linux mount behavior.
              Mode "uppercase" is like "stripped" but maps lowercase letters to uppercase, if any
              occur despite the prescriptions of ECMA-119.

       -disk_dev_ino "on"|"ino_only"|"off"
              Enable or disable processing of recorded file  identification  numbers  (dev_t  and
              ino_t).  If  enabled they are stored as xattr and can substantially accelerate file
              comparison. The root node gets a global start timestamp.  If  during  comparison  a
              file  with  younger  timestamps  is found in the ISO image, then it is suspected to
              have inconsistent content.
              If device numbers and inode numbers of the disk filesystems are persistent  and  if
              no  irregular  alterations  of  timestamps  or  system clock happen, then potential
              content changes can be detected without reading that content.  File content  change
              is assumed if any of mtime, ctime, device number or inode number have changed.
              Mode  "ino_only"  replaces  the  precondition that device numbers are stable by the
              precondition that mount points in  the  compared  tree  always  lead  to  the  same
              filesystems. Use this if mode "on" always sees all files changed.
              The  speed  advantage  appears  only  if  the  loaded  session  was  produced  with
              -disk_dev_ino "on" too.
              Note that -disk_dev_ino "off" is totally in effect only  if  -hardlinks  is  "off",
              too.

       -file_name_limit [+]number
              Set  the maximum permissible length for file names in the range of 64 to 255.  Path
              components which are longer than the given number will get truncated and have their
              last  33  bytes overwritten by a colon ':' and the hex representation of the MD5 of
              the first 4095 bytes of  the  whole  oversized  name.  Potential  incomplete  UTF-8
              characters will get their leading bytes replaced by '_'.
              iso_rr_paths  with  the long components will still be able to access the file paths
              with truncated components.
              If -file_name_limit is executed while an ISO tree is present, the file names in the
              ISO tree get checked for existing truncated file names of the current limit and for
              name collisions between newly truncated files and existing files.  In  both  cases,
              the setting will be refused with a SORRY event.
              One  may  lift  this  ban  by  prepending  the  character  "+"  to  the argument of
              -file_name_limit. Truncated filenames may then get  truncated  again,  invalidating
              their  MD5  part.  Colliding  truncated names are made unique, consuming at least 9
              more bytes of the remaining name part.
              If writing of xattr is enabled, then the length will be stored in "isofs.nt" of the
              root  directory.   If reading of xattr is enabled and "isofs.nt" is found, then the
              found length will get into effect if it is smaller  than  the  current  setting  of
              -file_name_limit.
              File  name  patterns  will  only work if they match the truncated name.  This might
              change in future.
              Files with truncated names get deleted and re-added unconditionally during  -update
              and -update_r. This might change in future.
              Linux  kernels up to at least 4.1 misrepresent names of length 254 and 255.  If you
              expect such names in or under disk_paths and plan to mount the ISO  by  such  Linux
              kernels,  consider  to set -file_name_limit 253.  Else just avoid names longer than
              253 characters.

       -rom_toc_scan "on"|"force"|"off"[:"emul_off"][:"emul_wide"]
              Read-only drives do not tell the actual media type but show any media as ROM  (e.g.
              as  DVD-ROM).  The session history of MMC multi-session media might be truncated to
              first and last session or even be  completely  false.   (The  emulated  history  of
              overwriteable media is not affected by this.)
              To  have  in case of failure a chance of getting the session history and especially
              the address of the last session, there is a scan for ISO  9660  filesystem  headers
              which  might  help  but  also  might  yield worse results than the drive's table of
              content. At its end it can cause read attempts to invalid addresses and  thus  ugly
              drive behavior.  Setting "on" enables that scan for alleged read-only media.
              Some  operating  systems  are  not  able  to  mount  the  most  recent  session  of
              multi-session DVD or BD. If on such a system xorriso has no  own  MMC  capabilities
              then  it  may  still  find  that  session  from a scanned table of content. Setting
              "force" handles any media like a ROM medium with setting "on".
              On the other hand the emulation of  session  history  on  overwriteable  media  can
              hamper  reading  of  partly  damaged  media.  Setting  "off:emul_off"  disables the
              elsewise trustworthy table-of-content scan for those media.
              The table-of-content scan on overwriteable media normally searches only up  to  the
              end  of  the  session  that  is  pointed  to by the superblock at block 0.  Setting
              "on:emul_wide" lets the scan continue up to the end of the  medium.   This  may  be
              useful  after  copying  a  medium with -check_media patch_lba0=on when not the last
              session was loaded.

       -calm_drive "in"|"out"|"all"|"revoke"|"on"|"off"
              Reduce drive noise until it is actually used again.  Some  drives  stay  alert  for
              substantial  time  after  they have been used for reading. This reduces the startup
              time for the next drive operation but can be loud and waste energy if no  i/o  with
              the drive is expected to happen soon.
              Modes   "in",  "out",  "all"  immediately  calm  down  -indev,  -outdev,  or  both,
              respectively.  Mode "revoke" immediately alerts both.  Mode "on" causes -calm_drive
              to  be  performed  automatically  after  each -dev, -indev, and -outdev. Mode "off"
              disables this.

       -ban_stdio_write
              Allow for writing only the usage of MMC  optical  drives.  Disallow  to  write  the
              result  into  files  of  nearly  arbitrary  type.  Once set, this command cannot be
              revoked.

       -early_stdio_test "on"|"appendable_wo"|"off"
              If enabled by "on" then regular files and block devices get  tested  for  effective
              access  permissions.  This  implies  to  try opening those files for writing, which
              otherwise will happen only later and only if actual writing is desired.
              The test result is  used  for  classifying  the  pseudo  drives  as  overwriteable,
              read-only,  write-only,  or  uselessly empty. This may lead to earlier detection of
              severe problems, and may avoid some less severe error events.
              Mode "appendable_wo" is like "on"  with  the  additional  property  that  non-empty
              write-only files are regarded as appendable rather than blank.

       -data_cache_size number_of_tiles blocks_per_tile
              Set  the  size  and granularity of the data cache which is used when ISO images are
              loaded and when file content is read from ISO images. The cache consists of several
              tiles,  which  each consists of several blocks. A larger cache reduces the need for
              tiles being read multiple times. Larger tiles might additionally improve  the  data
              throughput  from  the drive, but can be wasteful if the data are scattered over the
              medium.
              Larger cache sizes help best with image  loading  from  MMC  drives.  They  are  an
              inferior alternative to -osirrox option "sort_lba_on".
              blocks_per_tile  must  be  a power of 2. E.g. 16, 32, or 64. The overall cache size
              must not exceed 1 GiB.  The default values can be restored by  parameter  "default"
              instead  of  one  or  both of the numbers.  Currently the default is 32 tiles of 32
              blocks = 2 MiB.

       Inserting files into ISO image:

       The following commands expect file addresses of two kinds:
       disk_path is a path to an object in the local filesystem tree.
       iso_rr_path is the Rock Ridge name of a file object in the ISO image.  If  no  Rock  Ridge
       information  is  recorded  in the loaded ISO image, then you will see ISO 9660 names which
       are of limited length and character set.  If no Rock Ridge information shall be stored  in
       an  emerging  ISO image, then their names will get mapped to such restricted ISO 9660 (aka
       ECMA-119) names.

       Note that in the ISO image you are as powerful as the superuser. Access permissions of the
       existing files in the image do not apply to your write operations. They are intended to be
       in effect with the read-only mounted image.

       If the iso_rr_path of a newly inserted file leads to an existing file object  in  the  ISO
       image, then the following collision handling happens:
       If  both  objects  are  directories  then  they  get  merged  by recursively inserting the
       subobjects from filesystem into ISO image.  If other file types collide then  the  setting
       of command -overwrite decides.
       Renaming  of  files  has similar collision handling, but directories can only be replaced,
       not merged. Note that if the target directory exists, then -mv inserts the source  objects
       into  this  directory  rather  than  attempting to replace it. Command -move, on the other
       hand, would attempt to replace it.

       The commands in this section alter the ISO image and not the local filesystem.

       -disk_pattern "on"|"ls"|"off"
              Set the pattern expansion mode for the disk_path  parameters  of  several  commands
              which support this feature.
              Setting  "off"  disables this feature for all commands which are marked in this man
              page by "disk_path [***]" or "disk_pattern [***]".
              Setting "on" enables it for all those commands.
              Setting "ls" enables it only for those which are marked by "disk_pattern [***]".
              Default is "ls".

       -add pathspec [...] | disk_path [***]
              Insert the given files or directory trees from filesystem into the ISO image.
              If -pathspecs is set to "on" or  "as_mkisofs"  then  pattern  expansion  is  always
              disabled  and  character '=' has a special meaning. It separates the ISO image path
              from the disk path:
              iso_rr_path=disk_path
              Character '=' in the iso_rr_path must be escaped by '\' (i.e. as "\=").
              With -pathspecs "on", the character '\' must not be escaped. The character  '='  in
              the disk_path must not be escaped.
              With  -pathspecs  "as_mkisofs",  all  characters  '\'  must  be  escaped  in  both,
              iso_rr_path and disk_path. The character '=' may or  may  not  be  escaped  in  the
              disk_path.
              If  iso_rr_path  does  not begin with '/' then -cd is prepended.  If disk_path does
              not begin with '/' then -cdx is prepended.
              If no '=' is given then the word is used as both, iso_rr_path and disk path.  If in
              this  case the word does not begin with '/' then -cdx is prepended to the disk_path
              and -cd is prepended to the iso_rr_path.
              If -pathspecs is set to "off" then -disk_pattern  expansion  applies,  if  enabled.
              The  resulting  words  are  used  as both, iso_rr_path and disk path. Relative path
              words get prepended the setting of -cdx to disk_path and  the  setting  of  -cd  to
              iso_rr_path.

       -add_plainly mode
              If  set to mode "unknown" then any command word that does not begin with "-" and is
              not recognized as known command will be subject to a virtual -add command.  I.e. it
              will  be  used  as  pathspec  or  as disk_path and added to the image.  If enabled,
              -disk_pattern expansion applies to disk_paths.
              Mode "dashed" is similar to "unknown" but also adds unrecognized command words even
              if they begin with "-".
              Mode  "any"  announces  that  all  further  words  are  to be added as pathspecs or
              disk_paths. This does not work in dialog mode.
              Mode "none" is the default. It prevents any words from being understood as files to
              add, if they are not parameters to appropriate commands.

       -path_list disk_path
              Like  -add  but  read  the parameter words from file disk_path or standard input if
              disk_path is "-".  The list must contain exactly one pathspec or disk_path  pattern
              per line.

       -quoted_path_list disk_path
              Like -path_list but with quoted input reading rules. Lines get split into parameter
              words for -add. Whitespace outside quotes is discarded.

       -map disk_path iso_rr_path
              Insert file object disk_path into the ISO image as iso_rr_path. If disk_path  is  a
              directory then its whole sub tree is inserted into the ISO image.

       -map_single disk_path iso_rr_path
              Like -map, but if disk_path is a directory then its sub tree is not inserted.

       -map_l disk_prefix iso_rr_prefix disk_path [***]
              Perform  -map  with  each of the disk_path parameters. iso_rr_path will be composed
              from disk_path by replacing disk_prefix by iso_rr_prefix.

       -update disk_path iso_rr_path
              Compare file object disk_path with file object iso_rr_path. If they do  not  match,
              then  perform the necessary image manipulations to make iso_rr_path a matching copy
              of disk_path. By default this comparison will imply lengthy content reading  before
              a  decision  is  made.  Commands -disk_dev_ino or -md5 may accelerate comparison if
              they were already in effect when the loaded session was recorded.
              If disk_path is a directory and iso_rr_path does not  exist  yet,  then  the  whole
              subtree will be inserted. Else only directory attributes will be updated.

       -update_r disk_path iso_rr_path
              Like  -update  but  working recursively. I.e. all file objects below both addresses
              get compared whether they have counterparts below the  other  address  and  whether
              both  counterparts  match.  If  there  is  a  mismatch  then  the  necessary update
              manipulation is done.
              Note that the comparison result may depend on command -follow. Its  setting  should
              always be the same as with the first adding of disk_path as iso_rr_path.
              If iso_rr_path does not exist yet, then it gets added. If disk_path does not exist,
              then iso_rr_path gets deleted.

       -update_l disk_prefix iso_rr_prefix disk_path [***]
              Perform -update_r with each  of  the  disk_path  parameters.  iso_rr_path  will  be
              composed from disk_path by replacing disk_prefix by iso_rr_prefix.

       -update_li iso_rr_prefix disk_prefix iso_rr_path [***]
              Perform  -update_r  with  each  of  the  iso_rr_path  parameters. disk_path will be
              composed from iso_rr_path by replacing iso_rr_prefix by disk_prefix.

       -update_lxi disk_prefix iso_rr_prefix disk_path [***]
              Perform -update_r with each of the disk_path parameters and  with  iso_rr_paths  in
              the ISO filesystem which are derived from the disk_path parameters after exchanging
              disk_prefix by iso_rr_prefix.  So,  other  than  -update_l,  this  detects  missing
              matches of disk_path and deletes the corresponding iso_rr_path.
              Note  that  relative disk_paths and disk_path patterns are interpreted as sub paths
              of the current disk working directory  -cdx.  The  corresponding  iso_rr_paths  are
              derived  by  exchanging  disk_prefix  by  iso_rr_prefix  before  pattern  expansion
              happens. The current -cdi directory has no influence.

       -cut_out disk_path byte_offset byte_count iso_rr_path
              Map a byte interval of a regular disk file into a regular file in  the  ISO  image.
              This  may  be  necessary  if the disk file is larger than a single medium, or if it
              exceeds the traditional limit of 2 GiB - 1 for old operating systems, or the  limit
              of  4  GiB  - 1 for newer ones. Only the newest Linux kernels seem to read properly
              files >= 4 GiB - 1.
              A clumsy remedy for this limit is to backup file pieces and to concatenate them  at
              restore time. A well tested chopping size is 2047m.  It is permissible to request a
              higher byte_count than available. The resulting  file  will  be  truncated  to  the
              correct  size  of  a  final  piece.  To request a byte_offset higher than available
              yields no file in the ISO image but a SORRY event.  E.g:
               -cut_out /my/disk/file 0 2047m \
               /file/part_1_of_3_at_0_with_2047m_of_5753194821 \
               -cut_out /my/disk/file 2047m 2047m \
               /file/part_2_of_3_at_2047m_with_2047m_of_5753194821 \
               -cut_out /my/disk/file 4094m 2047m \
               /file/part_3_of_3_at_4094m_with_2047m_of_5753194821
              While command -split_size is set larger than 0, and if all pieces of a file  reside
              in  the  same  ISO directory with no other files, and if the names look like above,
              then their ISO directory will be recognized and handled like a regular  file.  This
              affects  commands  -compare*,  -update*,  and  overwrite  situations.   See command
              -split_size for details.

       -cpr disk_path [***] iso_rr_path
              Insert the given files or directory trees from filesystem into the ISO image.
              The rules for generating the ISO addresses are similar as with shell command cp -r.
              Nevertheless, directories of the iso_rr_path are created if necessary. Especially a
              not yet existing iso_rr_path will be handled as directory  if  multiple  disk_paths
              are  present.   The leafnames of the multiple disk_paths will be grafted under that
              directory as would be done with an existing directory.
              If a single disk_path is present then a non-existing iso_rr_path will get the  same
              type as the disk_path.
              If  a disk_path does not begin with '/' then -cdx is prepended.  If the iso_rr_path
              does not begin with '/' then -cd is prepended.

       -mkdir iso_rr_path [...]
              Create empty directories  if  they  do  not  exist  yet.   Existence  as  directory
              generates a WARNING event, existence as other file causes a FAILURE event.

       -lns target_text iso_rr_path
              Create  a  symbolic  link  with  address  iso_rr_path  which points to target_text.
              iso_rr_path may not exist yet.
              Hint: Command -clone produces the ISO equivalent of a hard link.

       -clone iso_rr_path_original iso_rr_path_copy
              Create a copy of the ISO file object  iso_rr_path_original  with  the  new  address
              iso_rr_path_copy.  If  the  original  is  a  directory  then  copy  all  files  and
              directories underneath. If iso_rr_path_original is a boot  catalog  file,  then  it
              gets not copied but is silently ignored.
              The  copied  ISO  file objects have the same attributes. Copied data files refer to
              the same content source as their originals.  The copies  may  then  be  manipulated
              independendly of their originals.
              This  command  will refuse execution if the address iso_rr_path_copy already exists
              in the ISO tree.

       -cp_clone iso_rr_path_original [***] iso_rr_path_dest
              Create copies of one or more ISO file objects as with command -clone.  In  case  of
              collision  merge  directories with existing ones, but do not overwrite existing ISO
              file objects.
              The rules for generating the copy addresses are the same as with command -cpr  (see
              above)  or shell command cp -r. Other than with -cpr, relative iso_rr_path_original
              will get prepended the  -cd  path  and  not  the  -cdx  path.  Consider  to  -mkdir
              iso_rr_path_dest before -cp_clone so the copy address does not depend on the number
              of iso_rr_path_original parameters.

       Settings for file insertion:

       -file_size_limit value [value [...]] --
              Set the maximum permissible size for a single data file. The values get  summed  up
              for  the actual limit. If the only value is "off" then the file size is not limited
              by xorriso.  Default is a limit of 100 extents, 4g -2k each:
               -file_size_limit 400g -200k --
              When mounting ISO 9660 filesystems, old operating systems can handle only files  up
              to 2g -1 --. Newer ones are good up to 4g -1 --.  You need quite a new Linux kernel
              to read correctly the final bytes of a file >= 4g if its size  is  not  aligned  to
              2048 byte blocks.
              xorriso's  own  data  read  capabilities  are not affected by operating system size
              limits. Such limits apply to mounting only. Nevertheless, the target filesystem  of
              an -extract must be able to take the file size.

       -not_mgt code[:code[...]]
              Control the behavior of the exclusion lists.
              Exclusion  processing  happens  before  disk_paths  get mapped to the ISO image and
              before disk files get compared with image files.  The absolute  disk  path  of  the
              source  is  matched  against the -not_paths list.  The leafname of the disk path is
              matched against the patterns in the -not_leaf list. If a match is detected then the
              disk  path  will  not  be  regarded as an existing file and not be added to the ISO
              image.
              Several codes are defined.  The _on/_off settings persist until they are revoked by
              their_off/_on counterparts.
              "erase" empties the lists which were accumulated by -not_paths and -not_leaf.
              "reset" is like "erase" but also re-installs default behavior.
              "off"  disables exclusion processing temporarily without invalidating the lists and
              settings.
              "on" re-enables exclusion processing.
              "param_off" applies exclusion processing only to paths below disk_path parameter of
              commands. I.e. explicitly given disk_paths are exempted from exclusion processing.
              "param_on"  applies  exclusion processing to command parameters as well as to files
              below such parameters.
              "subtree_off" with "param_on"  excludes  parameter  paths  only  if  they  match  a
              -not_paths item exactly.
              "subtree_on"  additionally  excludes  parameter  paths which lead to a file address
              below any -not_paths item.
              "ignore_off" treats excluded disk files as if they  were  missing.  I.e.  they  get
              reported with -compare and deleted from the image with -update.
              "ignore_on" keeps excluded files out of -compare or -update activities.

       -not_paths disk_path [***]
              Add the given paths to the list of excluded absolute disk paths. If a given path is
              relative, then the current -cdx is prepended to form  an  absolute  path.   Pattern
              matching,  if enabled, happens at definition time and not when exclusion checks are
              made.
              (Do not forget to end the list of disk_paths by "--")

       -not_leaf pattern
              Add a single shell parser  style  pattern  to  the  list  of  exclusions  for  disk
              leafnames. These patterns are evaluated when the exclusion checks are made.

       -not_list disk_path
              Read  lines  from disk_path and use each of them either as -not_paths parameter, if
              they contain a / character, or as -not_leaf pattern.

       -quoted_not_list disk_path
              Like -not_list but with quoted input reading rules. Each word  is  handled  as  one
              parameter for -not_paths or -not_leaf.

       -follow occasion[:occasion[...]]
              Enable  or  disable  resolution of symbolic links and mountpoints under disk_paths.
              This applies to actions -add, -du*x, -ls*x, -findx, -concat, and  to  -disk_pattern
              expansion.
              There are three kinds of follow decisison to be made:
              link  is  the hop from a symbolic link to its target file object for the purpose of
              reading. I.e. not for command -concat.  If enabled then symbolic links are  handled
              as their target file objects, else symbolic links are handled as themselves.
              mount is the hop from one filesystem to another subordinate filesystem.  If enabled
              then mountpoint directories are handled as any other  directory,  else  mountpoints
              are  handled  as  empty  directories  if  they  are  encountered  in directory tree
              traversals.
              concat is the hop from a symbolic link to its target file object for the purpose of
              writing. I.e. for command -concat. This is a security risk !
              Less general than above occasions:
              pattern is mount and link hopping, but only during -disk_pattern expansion.
              param  is  link hopping for parameter words (after eventual pattern expansion).  If
              enabled then -ls*x will show the link targets rather  than  the  links  themselves.
              -du*x,  -findx,  and  -add will process the link targets but not follow links in an
              eventual directory tree below the targets (unless "link" is enabled).
              Occasions can be combined in a colon separated list. All occasions mentioned in the
              list will then lead to a positive follow decision.
              off prevents any positive follow decision. Use it if no other occasion applies.
              Shortcuts:
              default is equivalent to "pattern:mount:limit=100".
              on always decides positive. Equivalent to "link:mount:concat".

              Not an occasion but an optional setting is:
              limit=<number>  which sets the maximum number of link hops.  A link hop consists of
              a sequence of symbolic links and a final target  of  different  type.  Nevertheless
              those hops can loop. Example:
                $ ln -s .. uploop
              Link  hopping  has  a  built-in  loop  detection  which  stops hopping at the first
              repetition of a link target. Then the repeated link is handled as itself and not as
              its  target.   Regrettably  one can construct link networks which cause exponential
              workload before their loops get detected.  The number given with "limit=" can  curb
              this workload at the risk of truncating an intentional sequence of link hops.

       -pathspecs "on"|"off"|"as_mkisofs"
              Control parameter interpretation with xorriso actions -add and -path_list.
              Mode "as_mkisofs" enables pathspecs of the form
              iso_rr_path=disk_path
              like with program mkisofs -graft-points.
              All  characters  '\'  must  be  escaped  in  both,  iso_rr_path and disk_path.  The
              character '=' must be escaped in the iso_rr_path and may or may not be  escaped  in
              the  disk_path.  This mode temporarily disables -disk_pattern expansion for command
              -add.
              Mode "on" does nearly the same. But '=' must only be escaped in the iso_rr_path and
              '\'  must  not be escaped at all. This has the disadvantage that one cannot express
              an iso_rr_path which ends by '\'.
              Mode  "off"  disables  pathspecs  of  the   form   target=source   and   re-enables
              -disk_pattern expansion.

       -overwrite "on"|"nondir"|"off"
              Allow  or disallow overwriting of existing files in the ISO image by files with the
              same name.
              With setting "off", name collisions with at  least  one  non-directory  file  cause
              FAILURE events. Collisions of two directories lead to merging of their file lists.
              With  setting  "nondir",  only  directories  are  protected  by  such events, other
              existing file types get treated with -rm before the new file gets  added.   Setting
              "on"  enables  automatic  -rm_r.  I.e.  a  non-directory  can  replace  an existing
              directory and all its subordinates.
              If restoring of files is enabled, then the overwrite rule  applies  to  the  target
              file objects on disk as well, but "on" is downgraded to "nondir".

       -split_size number["k"|"m"]
              Set  the  threshold for automatic splitting of regular files. Such splitting maps a
              large disk file onto a ISO directory with  several  part  files  in  it.   This  is
              necessary  if  the size of the disk file exceeds -file_size_limit.  Older operating
              systems can handle files in mounted ISO 9660 filesystems only if they  are  smaller
              than 2 GiB or in other cases 4 GiB.
              Default  is  0  which  will exclude files larger than -file_size_limit by a FAILURE
              event.  A well tested -split_size is 2047m. Sizes above  -file_size_limit  are  not
              permissible.
              While  command  -split_size  is  set larger than 0 such a directory with split file
              pieces will be recognized and handled like a regular file by commands  -compare*  ,
              -update*,   and   in   overwrite   situations.   There   are   -ossirox  parameters
              "concat_split_on" and "concat_split_off" which control the handling when files  get
              restored to disk.
              In  order  to  be  recognizable,  the  names of the part files have to describe the
              splitting by 5 numbers:
               part_number,total_parts,byte_offset,byte_count,disk_file_size
              which are embedded in the following text form:
               part_#_of_#_at_#_with_#_of_#
              Scaling characters like "m"  or  "k"  are  taken  into  respect.   All  digits  are
              interpreted as decimal, even if leading zeros are present.
              E.g: /file/part_1_of_3_at_0_with_2047m_of_5753194821
              No other files are allowed in the directory. All parts have to be present and their
              numbers have to be plausible. E.g. byte_count must be valid as  -cut_out  parameter
              and their contents may not overlap.

       File manipulations:

       The  following  commands  manipulate  files in the ISO image, regardless whether they stem
       from the loaded image or were newly inserted.

       -iso_rr_pattern "on"|"ls"|"off"
              Set the pattern expansion mode for the iso_rr_path parameters of  several  commands
              which support this feature.
              Setting  "off" disables pattern expansion for all commands which are marked in this
              man page by "iso_rr_path [***]" or "iso_rr_pattern [***]".
              Setting "on" enables it for all those commands.
              Setting "ls" enables it only for those which are marked by "iso_rr_pattern [***]".
              Default is "on".

       -rm iso_rr_path [***]
              Delete the given files from the ISO image.
              Note: This does not free any space on the -indev medium, even if  the  deletion  is
              committed to that same medium.
              The  image  size  will  shrink  if  the  image  is written to a different medium in
              modification mode.

       -rm_r iso_rr_path [***]
              Delete the given files or directory trees from the ISO image.  See  also  the  note
              with command -rm.

       -rmdir iso_rr_path [***]
              Delete empty directories.

       -move iso_rr_path iso_rr_path
              Rename the file given by the first (origin) iso_rr_path to the second (destination)
              iso_rr_path.  Deviate from rules of shell command mv by not moving the origin  file
              underneath  an  existing destination directory. The origin file will rather replace
              such a directory, if this is allowed by command -overwrite.

       -mv iso_rr_path [***] iso_rr_path
              Rename the given file objects in the ISO tree to the last parameter  in  the  list.
              Use the same rules as with shell command mv.
              If  pattern  expansion  is  enabled  and  if  the  last parameter contains wildcard
              characters then it must match exactly  one  existing  file  address,  or  else  the
              command fails with a FAILURE event.

       -chown uid iso_rr_path [***]
              Set  ownership of file objects in the ISO image. uid may either be a decimal number
              or the name of a user known to the operating system.

       -chown_r uid iso_rr_path [***]
              Like -chown but affecting all files below eventual directories.

       -chgrp gid iso_rr_path [***]
              Set group attribute of file objects in the ISO image. gid  may either be a  decimal
              number or the name of a group known to the operating system.

       -chgrp_r gid iso_rr_path [***]
              Like -chgrp but affecting all files below eventual directories.

       -chmod mode iso_rr_path [***]
              Equivalent to shell command chmod in the ISO image.  mode is either an octal number
              beginning  with  "0"  or  a  comma  separated  list  of  statements  of  the   form
              [ugoa]*[+-=][rwxst]* .
              Like: go-rwx,u+rwx .
              Personalities: u=user, g=group, o=others, a=all
              Operators: + adds given permissions, - revokes given permissions, = revokes all old
              permissions and then adds the given ones.
              Permissions: r=read, w=write, x=execute|inspect, s=setuid|setgid, t=sticky bit
              For octal numbers see man 2 stat.

       -chmod_r mode iso_rr_path [***]
              Like -chmod but affecting all files below eventual directories.

       -setfacl acl_text iso_rr_path [***]
              Attach the given ACL to the given iso_rr_paths. If the  files  already  have  ACLs,
              then  those get deleted before the new ones get into effect.  If acl_text is empty,
              or contains the text "clear" or the text "--remove-all",  then  the  existing  ACLs
              will  be  removed  and  no new ones will be attached. Any other content of acl_text
              will be interpreted as a list of ACL entries. It may  be  in  the  long  multi-line
              format as put out by -getfacl but may also be abbreviated as follows:
              ACL  entries are separated by comma or newline. If an entry is empty text or begins
              with "#" then it will be ignored. A valid entry has to begin by  a  letter  out  of
              {ugom}  for  "user",  "group", "other", "mask". It has to contain two colons ":". A
              non-empty text between those ":" gives a user id or group id. After the second  ":"
              there may be letters out of {rwx- #}.  The first three give read, write, or execute
              permission.  Letters "-", " " and TAB are ignored. "#" causes the rest of the entry
              to be ignored. Letter "X" or any other letters are not supported. Examples:
                g:toolies:rw,u:lisa:rw,u:1001:rw,u::wr,g::r,o::r,m::rw
                group:toolies:rw-,user::rw-,group::r--,other::r--,mask::rw-
              A  valid  entry  may  be  prefixed by "d", some following characters and ":".  This
              indicates that the entry goes to the "default" ACL rather than to the "access" ACL.
              Example:
                u::rwx,g::rx,o::,d:u::rwx,d:g::rx,d:o::,d:u:lisa:rwx,d:m::rwx

       -setfacl_r acl_text iso_rr_path [***]
              Like -setfacl but affecting all files below eventual directories.

       -setfacl_list disk_path
              Read  the  output  of  -getfacl_r  or  shell command getfacl -R and apply it to the
              iso_rr_paths as  given  in  lines  beginning  with  "#  file:".  This  will  change
              ownership,  group  and  ACL of the given files.  If disk_path is "-" then lines are
              read from standard input. Line "@" ends the list, "@@@" aborts without changing the
              pending iso_rr_path.
              Since -getfacl and getfacl -R strip leading "/" from file paths, the setting of -cd
              does always matter.

       -setfattr [-]name value iso_rr_path [***]
              Attach the given xattr pair of name and value to the given  iso_rr_paths.   If  the
              given  name  is prefixed by "-", then the pair with that name gets removed from the
              xattr list. If name is "--remove-all" then all user namespace xattr  of  the  given
              iso_rr_paths get deleted. In case of deletion, value must be an empty text.
              Which  names  are  permissible  depends  on the setting of command -xattr.  "on" or
              "user" restricts them to namespace "user". I.e. a name has to look like "user.x" or
              "user.whatever".
              -xattr setting "any" enables names from all namespaces except "isofs".
              Values  and names undergo the normal input processing of xorriso.  See also command
              -backslash_codes. Other than with command -setfattr_list, the byte value  0  cannot
              be expressed via -setfattr.

       -setfattr_r [-]name value iso_rr_path [***]
              Like -setfattr but affecting all files below eventual directories.

       -setfattr_list disk_path
              Read the output format of -getfattr_r or shell command getfattr -Rd and apply it to
              the iso_rr_paths as given in  lines  beginning  with  "#  file:".   All  previously
              existing  xattr  of  the acceptable namespaces will be deleted before the new xattr
              get attached. The set of acceptable names depends on the setting of command -xattr.
              If disk_path is "-" then lines are read from standard input.
              Since -getfattr and getfattr -Rd strip leading "/" from file paths, the setting  of
              -cd does always matter.
              Empty  input lines and lines which begin by "#" will be ignored (except "# file:").
              Line "@" ends the list, "@@@" aborts  without  changing  the  pending  iso_rr_path.
              Other input lines must have the form
                name="value"
              The separator "=" is not allowed in names.  Value may contain any kind of bytes. It
              must be in quotes. Trailing  whitespace  after  the  end  quote  will  be  ignored.
              Non-printables  bytes  and  quotes must be represented as \XYZ by their octal 8-bit
              code XYZ.  Use code \000 for 0-bytes.

       -alter_date type timestring iso_rr_path [***]
              Alter the date entries of files in the ISO image. type may be one of the following:
              "a" sets access time, updates ctime.
              "m" sets modification time, updates ctime.
              "b" sets access time and modification time, updates ctime.
              "a-c", "m-c", and "b-c" set the times without updating ctime.
              "c" sets the ctime.
              timestring may be in the following formats (see also section EXAMPLES):
              As expected by program date:
               MMDDhhmm[[CC]YY][.ss]]
              As produced by program date:
               [Day] MMM DD hh:mm:ss [TZON] YYYY
              Relative times counted from current clock time:
               +|-Number["s"|"h"|"d"|"w"|"m"|"y"]
              where "s" means seconds, "h" hours, "d" days, "w" weeks, "m"=30d, "y"=365.25d  plus
              1d added to multiplication result.
              Absolute seconds counted from Jan 1 1970:
               =Number
              xorriso's own timestamps:
               YYYY.MM.DD[.hh[mm[ss]]]
              scdbackup timestamps:
               YYMMDD[.hhmm[ss]]
              where "A0" is year 2000, "B0" is 2010, etc.
              ECMA-119 volume timestamps:
               YYYYMMDDhhmmsscc
              These are normally given as GMT. The suffix "LOC" causes local timezone conversion.
              E.g. 2013010720574700, 2013010720574700LOC.  The last two digits cc  (centiseconds)
              will be ignored, but must be present in order to make the format recognizable.
              Example:
                -alter_date m-c 2013.11.27.103951 /file1 /file2 --
              This  command  does  not  persistently  apply to the boot catalog, which gets fresh
              timestamps at -commit time. Command -volume_date "uuid" can set this time value.

       -alter_date_r type timestring iso_rr_path [***]
              Like -alter_date but affecting all files below eventual directories.

       -hide hide_state iso_rr_path [***]
              Prevent the names of the given files from showing up in the directory trees of  ISO
              9660  and/or  Joliet  and/or HFS+ when the image gets written.  The data content of
              such hidden files will be included in the resulting image, even if they do not show
              up  in  any  directory.   But  you will need own means to find nameless data in the
              image.
              Warning: Data which are hidden from the ISO 9660 tree will not  be  copied  by  the
              write method of modifying.
              Possible values of hide_state are: "iso_rr" for hiding from ISO 9660 tree, "joliet"
              for Joliet tree, "hfsplus" for HFS+, "on" for them all.  "off" means visibility  in
              all directory trees.
              These values may be combined.  E.g.: joliet:hfsplus
              This  command  does  not  apply to the boot catalog.  Rather use: -boot_image "any"
              "cat_hidden=on"

       Tree traversal command -find:

       -find iso_rr_path [test [op] [test ...]] [-exec action [params]] --
              A restricted substitute for shell command find in the ISO image.   It  performs  an
              action on matching file objects at or below iso_rr_path.
              If  not  used  as  last  command  in  the line then the parameter list needs to get
              terminated by "--".
              Tests are optional. If they are omitted then action is applied to all file objects.
              If  tests  are  given then they form together an expression.  The action is applied
              only if the expression matches the file object. Default expression operator between
              tests is -and, i.e. the expression matches only if all its tests match.
              Available tests are:
              -name  pattern : Matches if pattern matches the file leaf name. If the pattern does
              not contain any of the characters "*?[", then it will  be  truncated  according  to
              -file_name_limit and thus match the truncated name in the ISO filesystem.
              -wholename  pattern  :  Matches  if  pattern  matches  the file path as it would be
              printed by action "echo". Character '/' can be matched  by  wildcards.  If  pattern
              pieces  between  '/'  do  not  contain  any  of  the characters "*?[", they will be
              truncated according to -file_name_limit.
              -disk_name pattern : Like -name but testing the leaf name of  the  file  source  on
              disk.   Can  match  only data files which do not stem from the loaded image, or for
              directories above such data files. With directories the result can  change  between
              -find runs if their content stems from multiple sources.
              -disk_path  disk_path  : Matches if the given disk_path is equal to the path of the
              file source on disk. The same restrictions apply as with -disk_name.
              -type type_letter : Matches files  of  the  given  type:  "block",  "char",  "dir",
              "pipe", "file", "link", "socket", "eltorito", and "Xotic" which matches what is not
              matched by the other types.
              Only the first letter is interpreted.  E.g.: -find / -type d
              -maxdepth number : Matches only files which are at most at the  given  depth  level
              relative to the iso_rr_path where -find starts. That path itself is at depth 0, its
              directory children are at 1, their directory children at 2, and so on.
              -mindepth number : Matches only files which are at least at the given depth level.
              -damaged : Matches files which use data blocks marked as damaged by a previous  run
              of -check_media. The damage info vanishes when a new ISO image gets loaded.
              Note  that  a  MD5  session mismatch marks all files of the session as damaged.  If
              finer distinction is desired, perform -md5 off before -check_media.
              -pending_data : Matches files which get their content from outside the  loaded  ISO
              image.
              -lba_range  start_lba  block_count : Matches files which use data blocks within the
              range of start_lba and start_lba+block_count-1.
              -has_acl : Matches files which have a non-trivial ACL.
              -has_xattr : Matches files which have xattr name-value pairs from user namespace.
              -has_aaip : Matches files which have ACL or any xattr.
              -has_any_xattr : Matches files which have any xattr other than ACL.
              -has_md5 : Matches data files which have MD5 checksums.
              -has_hfs_crtp creator type : Matches files which have the given  HFS+  creator  and
              type  attached.   These  are  codes of 4 characters which get stored if -hfsplus is
              enabled. Use a single dash '-' as wildcard that matches any such code.  E.g:.
               -has_hfs_crtp YYDN TEXT
               -has_hfs_crtp - -
              -has_hfs_bless blessing : Matches files which bear the given HFS+ blessing. It  may
              be   one   of   :  "ppc_bootdir",  "intel_bootfile",  "show_folder",  "os9_folder",
              "osx_folder", "any". See also action set_hfs_bless.
              -has_filter : Matches files which are filtered by -set_filter.
              -hidden hide_state : Matches files which are hidden in "iso_rr" tree,  in  "joliet"
              tree, in "hfsplus" tree, in all trees ("on"), or not hidden in any tree ("off").
              Those which are hidden in some tree match -not -hidden "off".
              -bad_outname namespace : Matches files with names which change when converted forth
              and back between the local character set and one  of  the  namespaces  "rockridge",
              "joliet", "ecma119", "hfsplus".
              All  applicable  -compliance  rules are taken into respect.  Rule "omit_version" is
              always enabled, because else namespaces "joliet" and "ecma119" would cause  changes
              with  every  non-directory name.  Consider to also enable rules "no_force_dots" and
              "no_j_force_dots".
              The namespaces use different character sets and apply further restrictions to  name
              length,  permissible  characters,  and mandatory name components.  "rockridge" uses
              the character set defined by -out_charset, "joliet" uses  UCS-2BE,  "ecma119"  uses
              ASCII, "hfsplus" uses UTF-16BE.
              -name_limit_blocker  length  :  Matches  file  names  which  would  prevent command
              -file_name_limit with the given length. The command itself reports only  the  first
              problem file.
              -prune : If this test is reached and the tested file is a directory then -find will
              not dive into that directory. This test itself does always match.
              -use_pattern "on"|"off" : This pseudo test controls the interpretation of wildcards
              with tests -name, -wholename, and -disk_name. Default is "on". If interpretation is
              disabled by "off", then the parameters of -name, -wholename, and -disk_name have to
              match literally rather than as search pattern.  This test itself does always match.
              -or_use_pattern  "on"|"off"  :  Like  -use_pattern, but automatically appending the
              test by -or rather than by -and. Further the test itself does  never  match.  So  a
              subsequent test -or will cause its other operand to be performed.
              -decision "yes"|"no" : If this test is reached then the evaluation ends immediately
              and action is performed if the decision is "yes" or "true". See operator -if.
              -true and -false : Always match or match not, respectively. Evaluation goes on.
              -sort_lba : Always match. This causes -find to perform its  action  in  a  sequence
              sorted  by  the  ISO  image block addresses of the files. It may improve throughput
              with actions which read data from  optical  drives.  Action  will  always  get  the
              absolute path as parameter.
              Available operators are:
              -not : Matches if the next test or sub expression does not match.  Several tests do
              this specifically:
              -undamaged,  -lba_range  with  negative  start_lba,   -has_no_acl,   -has_no_xattr,
              -has_no_aaip, -has_no_filter .
              -and : Matches if both neighboring tests or expressions match.
              -or : Matches if at least one of both neighboring tests or expressions matches.
              -sub  ...  -subend or ( ... ) : Enclose a sub expression which gets evaluated first
              before it is processed by neighboring operators.  Normal precedence is: -not, -or ,
              -and.
              -if ... -then ... -elseif ... -then ...  -else ... -endif : Enclose one or more sub
              expressions. If the -if expression matches, then the -then expression is  evaluated
              as  the  result  of  the  whole  expression  up  to  -endif.  Else the next -elseif
              expression is evaluated and if it matches, its -then expression. Finally in case of
              no  match,  the -else expression is evaluated.  There may be more than one -elseif.
              Neither -else nor -elseif are mandatory.  If -else is missing  and  would  be  hit,
              then the result is a non-match.
              -if-expressions are the main use case for above test -decision.

              Default  action is echo, i.e. to print the address of the found file. Other actions
              are certain xorriso commands  which  get  performed  on  the  found  files.   These
              commands may have specific parameters. See also their particular descriptions.
              chown  and  chown_r  change  the  ownership and get the user id as parameter. E.g.:
              -exec chown thomas --
              chgrp and chgrp_r change the group attribute and get the  group  id  as  parameter.
              E.g.: -exec chgrp_r staff --
              chmod  and  chmod_r  change  access permissions and get a mode string as parameter.
              E.g.: -exec chmod a-w,a+r --
              alter_date and alter_date_r change the timestamps. They get a type character and  a
              timestring as parameters.
              E.g.: -exec alter_date "m" "Dec 30 19:34:12 2007" --
              set_to_mtime sets the ctime and atime to the value found in mtime.
              lsdl prints file information like shell command ls -dl.
              compare  performs  command  -compare with the found file address as iso_rr_path and
              the corresponding file address below its parameter disk_path_start.  For  this  the
              iso_rr_path of the -find command gets replaced by the disk_path_start.
              E.g.: -find /thomas -exec compare /home/thomas --
              update  performs  command  -update  with the found file address as iso_rr_path. The
              corresponding file address is determined like with above action "compare".
              update_merge is like update but does not delete the found file if it is missing  on
              disk.  It may be run several times and records with all visited files whether their
              counterpart on disk has  already  been  seen  by  one  of  the  update_merge  runs.
              Finally,  a  -find  run  with  action  "rm_merge"  may remove all files that saw no
              counterpart on disk.
              Up to the next "rm_merge" or "clear_merge" all newly inserted files will get marked
              as having a disk counterpart.
              rm removes the found iso_rr_path from the image if it is not a directory with files
              in it. I.e. this "rm" includes "rmdir".
              rm_r removes the found iso_rr_path from the image, including whole directory trees.
              rm_merge removes the found iso_rr_path if it was visited by one  or  more  previous
              actions  "update_merge"  and saw no counterpart on disk in any of them. The marking
              from the update actions is removed in any case.
              clear_merge removes an eventual marking from action "update_merge".
              report_damage classifies files whether they hit a data  block  that  is  marked  as
              damaged. The result is printed together with the address of the first damaged byte,
              the maximum span of damages, file size, and the path of the file.
              report_lba prints files which are associated to image data blocks.   It  tells  the
              logical  block address, the block number, the byte size, and the path of each file.
              There may be reported more than one line per file if the file  has  more  than  one
              section.  In this case each line has a different extent number in column "xt".
              report_sections  like  report_lba  but  telling  the  byte  sizes of the particular
              sections rather than the overall byte size of the file.
              getfacl prints access permissions in ACL text form to the result channel.
              setfacl attaches ACLs after removing existing ones. The new ACL is  given  in  text
              form as defined with command -setfacl.
              E.g.: -exec setfacl u:lisa:rw,u::rw,g::r,o::-,m::rw --
              getfattr  prints  xattr  name-value  pairs  to  the  result  channel. The choice of
              namespaces depends on the setting of command -xattr: "on" or "user" restricts it to
              the namespace "user", "any" only omits namespace "isofs".
              get_any_xattr  prints  xattr  name-value pairs from any namespace except ACL to the
              result channel. This is mostly for debugging of namespace "isofs".
              list_extattr mode prints a script to the result channel, which  would  use  FreeBSD
              command  setextattr  to  set  the  file's xattr name-value pairs of user namespace.
              Parameter mode controls the form of the output of names and values.   Default  mode
              "e"  prints harmless characters in shell quotation marks, but represents texts with
              octal 001 to 037 and 0177 to 0377 by an embedded echo -e command.  Mode "q"  prints
              any characters in shell quotation marks. This might not be terminal-safe but should
              work in script files.  Mode "r" uses no quotation marks. Not safe.  Mode "b" prints
              backslash encoding. Not suitable for shell parsing.
              E.g. -exec list_extattr e --
              Command -backslash_codes does not affect the output.
              get_md5 prints the MD5 sum, if recorded, together with file path.
              check_md5  compares  the MD5 sum, if recorded, with the file content and reports if
              mismatch.
              E.g.: -find / -not -pending_data -exec check_md5 FAILURE --
              make_md5 equips a data file with an MD5 sum of its content. Useful to  upgrade  the
              files in the loaded image to full MD5 coverage by the next commit with -md5 "on".
              E.g.: -find / -type f -not -has_md5 -exec make_md5 --
              setfattr sets or deletes xattr name value pairs.
              E.g.: -find / -has_xattr -exec setfattr --remove-all '' --
              set_hfs_crtp adds, changes, or removes HFS+ creator and type attributes.
              E.g.: -exec set_hfs_crtp YYDN TEXT
              E.g.: -find /my/dir -prune -exec set_hfs_crtp --delete -
              get_hfs_crtp  prints  the  HFS+  creator  and  type  attributes  together  with the
              iso_rr_path, if the file has such attributes at all.
              E.g.: -exec get_hfs_crtp
              set_hfs_bless applies or removes HFS+  blessings.  They  are  roles  which  can  be
              attributed to up to four directories and a data file:
              "ppc_bootdir", "intel_bootfile", "show_folder", "os9_folder", "osx_folder".
              They may be abbreviated as "p", "i", "s", "9", and "x".
              Each  such  role  can be attributed to at most one file object. "intel_bootfile" is
              the one that would apply to a data file. All  others  apply  to  directories.   The
              -find  run will end as soon as the first blessing is issued. The previous bearer of
              the blessing will lose it then.  No file object can bear more than one blessing.
              E.g.: -find /my/blessed/directory -exec set_hfs_bless p
              Further there is blessing "none" or "n" which revokes any blessing from  the  found
              files. This -find run will not stop when the first match is reached.
              E.g.: -find / -has_hfs_bless any -exec set_hfs_bless none
              get_hfs_bless  prints  the  HFS+  blessing role and the iso_rr_path, if the file is
              blessed at all.
              E.g.: -exec get_hfs_bless
              set_filter applies or removes filters.
              E.g.: -exec set_filter --zisofs --
              mkisofs_r applies the rules of mkisofs -r to the file object:
              user id and group id become 0, all r-permissions get granted,  all  w  denied.   If
              there  is  any  x-permission,  then  all  three  x  get granted.  s- and t-bits get
              removed.
              sort_weight attributes a LBA weight number to regular files.
              The number may range from -2147483648 to 2147483647. The higher it  is,  the  lower
              will  be  the  block address of the file data in the emerging ISO image.  Currently
              the boot catalog has a hardcoded weight of 1 billion.  Normally  it  should  occupy
              the block with the lowest possible address.
              Data files which are loaded by -indev or -dev get a weight between 1 and 2 exp 28 =
              268,435,456, depending on their block address. This shall keep them roughly in  the
              same order if the write method of modifying is applied.
              Data  files  which  are  added  by other commands get an initial weight of 0.  Boot
              image files have a default weight of 2.
              E.g.: -exec sort_weight 3 --
              show_stream shows the content stream chain of a data file.
              show_stream_id is like show_stream, but also prints between stream type  and  first
              ":" in square brackets libisofs id numbers: [fs_id,dev_id,ino_id].
              hide  brings  the  file  into  one  of  the  hide  states "on", "iso_rr", "joliet",
              "hfsplus", "off". They may be combined. E.g.: joliet:hfsplus
              E.g.:
                -find / -disk_name *_secret -exec hide on
              print_outname prints in the first line the filename as registered  by  the  program
              model,  and in the second line the filename after conversion forth and back between
              local character set and one of the namespaces "rockridge", "joliet", "ecma119",  or
              "hfsplus". The third output line is "--" .
              The  name  conversion does not take into respect the possibility of name collisions
              in the target namespace. Such collisions are most likely in "joliet" and "ecma119",
              where they get resolved by automatic file name changes.
              E.g.:
                -find / -bad_outname joliet -exec print_outname joliet
              estimate_size  prints a lower and an upper estimation of the number of blocks which
              the found files together will occupy in the emerging  ISO  image.   This  does  not
              account  for  the  superblock,  for the directories in the -find path, or for image
              padding.
              find performs another run of -find on the matching file address.   It  accepts  the
              same params as -find, except iso_rr_path.
              E.g.:
                -find / -name '???' -type d -exec find -name '[abc]*' -exec chmod a-w,a+r --

       Filters for data file content:

       Filters  may  be  installed  between  data files in the ISO image and their content source
       outside the image. They may also be used vice versa between data content in the image  and
       target files on disk.
       Built-in  filters  are  "--zisofs"  and "--zisofs-decode". The former is to be applied via
       -set_filter, the latter is automatically applied if zisofs compressed content is  detected
       with a file when loading the ISO image.
       Another  built-in  filter  pair is "--gzip" and "--gunzip" with suffix ".gz".  They behave
       about like external gzip and gunzip but avoid forking a process for each single  file.  So
       they are much faster if there are many small files.

       -external_filter name option[:option] program_path [arguments] --
              Register  a  content  filter  by  associating  a  name with a program path, program
              arguments, and some behavioral options.  Once  registered  it  can  be  applied  to
              multiple  data  files in the ISO image, regardless whether their content resides in
              the loaded ISO image or in the local filesystem.   External  filter  processes  may
              produce  synthetic  file  content  by  reading  the original content from stdin and
              writing to stdout whatever they want.  They must deliver the  same  output  on  the
              same input in repeated runs.
              Options are:
               "default" means that no other option is intended.
               "suffix=..."  sets a file name suffix. If it is not empty then it will be appended
              to the file name or removed from it.
               "remove_suffix" will remove a file name suffix rather than appending it.
               "if_nonempty" will leave 0-sized files unfiltered.
               "if_reduction" will try filtering and revoke it  if  the  content  size  does  not
              shrink.
               "if_block_reduction" will revoke if the number of 2 kB blocks does not shrink.
               "used=..."  is  ignored.  Command  -status shows it with the number of files which
              currently have the filter applied.
              Examples:
               -external_filter bzip2 suffix=.bz2:if_block_reduction \
                                /usr/bin/bzip2 --
               -external_filter bunzip2 suffix=.bz2:remove_suffix \
                                /usr/bin/bunzip2 --

       -unregister_filter name
              Remove an -external_filter registration. This is only possible if the filter is not
              applied to any file in the ISO image.

       -close_filter_list
              Irrevocably  ban commands -concat "pipe", -external_filter, and -unregister_filter,
              but not -set_filter. Use this to prevent external filtering in general or when  all
              intended  filters  are  registered  and  -concat  mode  "pipe" shall be disallowed.
              External filters may also be banned totally at compile time of xorriso.  By default
              they are banned if xorriso runs under setuid permission.

       -set_filter name iso_rr_path [***]
              Apply  an  -external_filter or a built-in filter to the given data files in the ISO
              image.  If the filter suffix is not empty , then it will be  applied  to  the  file
              name.   Renaming only happens if the filter really gets attached and is not revoked
              by its options.  By default files which  already  bear  the  suffix  will  not  get
              filtered.  The  others  will get the suffix appended to their names.  If the filter
              has option "remove_suffix", then the filter will only be applied if the  suffix  is
              present  and  can  be  removed.  Name oversize or collision caused by suffix change
              will prevent filtering.
              With most filter types this command will immediately run the filter once  for  each
              file  in  order  to  determine  the  output  size.  Content reading operations like
              -extract , -compare and image generation  will  perform  further  filter  runs  and
              deliver filtered content.
              At  image  generation  time  the filter output must still be the same as the output
              from the first run. Filtering for image generation does not happen with files  from
              the  loaded  ISO  image if the write method of growing is in effect (i.e -indev and
              -outdev are identical).
              The reserved filter name "--remove-all-filters" revokes filtering. This will revoke
              suffix  renamings  as  well.   Use  "--remove-all-filters+"  to  prevent any suffix
              renaming.
              Attaching or detaching filters will not alter the state  of  -changes_pending.   If
              the  filter manipulations shall be the only changes in a write run, then explicitly
              execute -changes_pending "yes".

       -set_filter_r name iso_rr_path [***]
              Like -set_filter but affecting all data files below eventual directories.

       Writing the result, drive control:

       (see also paragraph about settings below)

       -rollback
              Discard the manipulated ISO image and reload it from -indev.  (Use -rollback_end if
              immediate program end is desired.)

       -changes_pending "no"|"yes"|"mkisofs_printed"|"show_status"
              Write  runs  are  performed  only  if a change of the image has been made since the
              image was loaded or created blank. Vice versa the program will start  a  write  run
              for  pending  changes  when  it ends normally (i.e. not by abort and not by command
              -rollback_end).
              The command -changes_pending can be used to override the  automatically  determined
              state.  This  is mainly useful for setting state "yes" despite no real changes were
              made. The  sequence  -changes_pending  "no"  -end  is  equivalent  to  the  command
              -rollback_end.  State  "mkisofs_printed" is caused by emulation command -as mkisofs
              if option -print-size is present.
              The pseudo-state "show_status" can be used to print the  current  state  to  result
              channel.
              Image  loading  or  manipulations which happen after this command will again update
              automatically the change status of the image.

       -commit
              Perform the write operation. Afterwards, if -outdev is readable, make  it  the  new
              -dev and load the image from there.  Switch to growing mode.  (A subsequent -outdev
              will  activate  modification  mode  or  blind  growing.)   -commit   is   performed
              automatically at end of program if there are uncommitted manipulations pending.
              So,  to  perform  a  final  write  operation with no new -dev and no new loading of
              image, rather execute command -end.  If you want to go on  without  image  loading,
              execute  -commit_eject  "none".   To  eject  after write without image loading, use
              -commit_eject "all".
              To suppress a final write, execute -rollback_end.

              Writing can last quite a while. It is not unnormal with several types of media that
              there  is  no progress visible for the first few minutes or that the drive gnaws on
              the medium for a few minutes after all data have been transmitted.  xorriso and the
              drives  are  in  a  client-server relationship.  The drives have much freedom about
              what to do with the media.  Some combinations of drives and  media  simply  do  not
              work, despite the promises by their vendors.  If writing fails then try other media
              or another drive. The reason for such failure is hardly ever in  the  code  of  the
              various  burn  programs  but  you may well try some of those listed below under SEE
              ALSO.

       -eject "in"|"out"|"all"
              Eject the medium in -indev, -outdev, or both drives, respectively.  Note: It is not
              possible yet to effectively eject disk files.

       -commit_eject "in"|"out"|"all"|"none"
              Combined  -commit and -eject. When writing has finished do not make -outdev the new
              -dev, and load no ISO image. Rather  eject  -indev  and/or  -outdev.  Give  up  any
              non-ejected drive.

       -blank mode
              Make media ready for writing from scratch (if not -dummy is activated).
              This  affects  only the -outdev not the -indev.  If both drives are the same and if
              the ISO image was altered then this command leads  to  a  FAILURE  event.   Defined
              modes are:
                as_needed, fast, all, deformat, deformat_quickest
              "as_needed"  cares  for  used  CD-RW,  DVD-RW  and  for used overwriteable media by
              applying -blank "fast". It applies -format "full" to  yet unformatted  DVD-RAM  and
              BD-RE.  Other  media  in blank state are gracefully ignored.  Media which cannot be
              made ready for writing from scratch cause a FAILURE event.
              "fast" makes CD-RW and unformatted DVD-RW re-usable, or  invalidates  overwriteable
              ISO images. "all" might work more thoroughly and need more time.
              "deformat" converts overwriteable DVD-RW into unformatted ones.
              "deformat_quickest"  is a faster way to deformat or blank DVD-RW but produces media
              which are only suitable for a single session.  Some drives announce this  state  by
              not  offering  feature  21h,  but  some  drives offer it anyway.  If feature 21h is
              missing, then xorriso will refuse to write on DVD-RW if not command -close  is  set
              to "on".
              The progress reports issued by some drives while blanking are quite unrealistic. Do
              not conclude success  or  failure  from  the  reported  percentages.  Blanking  was
              successful if no SORRY event or worse occurred.
              Mode may be prepended by "force:" in order to override the evaluation of the medium
              state by libburn. E.g. "force:fast".  Blanking will nevertheless  only  succeed  if
              the drive is willing to do it.

       -format mode
              Convert  unformatted  DVD-RW into overwriteable ones, "de-ice" DVD+RW, format newly
              purchased BD-RE or BD-R, re-format DVD-RAM or BD-RE.
              Defined modes are:
                as_needed, full, fast, by_index_<num>, fast_by_index_<num>,
                by_size_<num>, fast_by_size_<num>, without_spare
              "as_needed" formats yet unformatted DVD-RW, DVD-RAM, BD-RE,  or  blank  unformatted
              BD-R. Other media are left untouched.
              "full" (re-)formats DVD-RW, DVD+RW, DVD-RAM, BD-RE, or blank unformatted BD-R.
              "fast" does the same as "full" but tries to be quicker.
              "by_index_"  selects  a  format  out  of  the  descriptor  list  issued  by command
              -list_formats. The index number from that list is to be appended to the mode  word.
              E.g: "by_index_3".
              "fast_by_index_" does the same as "by_index_" but tries to be quicker.
              "by_size_"  selects a format out of the descriptor list which provides at least the
              given size. That size is to be appended to the mode  word.   E.g:  "by_size_4100m".
              This  applies  to media with Defect Management.  On BD-RE it will not choose format
              0x31, which offers no Defect Management.
              "fast_by_size_" does the same as "by_size_" but tries to be quicker.
              "without_spare" selects the  largest  format  out  of  the  descriptor  list  which
              provides no Spare Area for Defect Management. On BD-RE this will be format 0x31.
              The formatting action has no effect on media if -dummy is activated.
              Formatting  is  normally needed only once during the lifetime of a medium, if ever.
              But it is a reason for re-formatting if:
               DVD-RW was deformatted by -blank,
               DVD+RW has read failures (re-format before next write),
               DVD-RAM or BD-RE shall change their amount of defect reserve.
              BD-R may be written unformatted or may be formatted before first  use.   Formatting
              activates  Defect  Management  which  tries  to catch and repair bad spots on media
              during the write process at the expense of half speed even with flawless media.
              The progress reports issued by some drives while formatting are quite  unrealistic.
              Do  not  conclude  success or failure from the reported percentages. Formatting was
              successful if no SORRY event or worse occurred. Be patient with  apparently  frozen
              progress.

       -list_formats
              Put  out  a  list  of  format  descriptors  as reported by the output drive for the
              current medium. The list gives the index number after "Format idx",  a  MMC  format
              code, the announced size in blocks (like "2236704s") and the same size in MiB.
              MMC  format codes are manifold. Most important are: "00h" general formatting, "01h"
              increases reserve space for DVD-RAM, "26h" for DVD+RW, "30h" for BD-RE with reserve
              space, "31h" for BD-RE without reserve space, "32h" for BD-R.
              Smaller format size with DVD-RAM, BD-RE, or BD-R means more reserve space.

       -list_speeds
              Put out a list of speed values as reported by the drives with the loaded media. The
              list tells read speeds of the input drive and of the output drive. Further it tells
              write speeds of the output drive.
              The  list  of write speeds does not necessarily mean that the medium is writable or
              that these speeds are actually achievable. Especially the lists reported with empty
              drive or with ROM media obviously advertise speeds for other media.
              It  is  not  mandatory  to  use speed values out of the listed range.  The drive is
              supposed to choose a safe speed that is as near to the desired speed as possible.
              At the end of the list, "Write speed L" and "Write speed H" are  the  best  guesses
              for  lower  and  upper  write speed limit.  "Write speed l" and "Write speed h" may
              appear only with CD and eventually override the list of other speed offers.
              Only if the drive reports contradicting speed information there will appear  "Write
              speed  0",  which  tells  the outcome of speed selection by command -speed 0, if it
              deviates from "Write speed H".
              "Read speed L" and "Read speed H" tell the minimum  and  maximum  read  speeds,  as
              reported  by  the drive. They would be chosen by -read_speed "min" or "max" if they
              undercut or surpass  the  built-in  limits.  These  are  "1x",  "52xCD",  "24xDVD",
              "20xBD".

       -close_damaged "as_needed"|"force"
              Try  to  close  the  upcoming track and session if the drive reported the medium as
              damaged. This may apply to CD-R, CD-RW, DVD-R, DVD-RW, DVD+R,  DVD+R  DL,  or  BD-R
              media.  It  is indicated by warning messages when the drive gets acquired, and by a
              remark "but next track is damaged" with the line "Media status :" of command -toc.
              The setting of command -close determines whether the medium stays appendable.
              Mode "as_needed" gracefully refuses on media which are  not  reported  as  damaged.
              Mode "force" attempts the close operation even with media which appear undamaged.
              No image changes are allowed to be pending before this command is performed.  After
              closing was attempted, both drives are given up.

       -list_profiles "in"|"out"|"all"
              Put out a list of media types supported by -indev, -outdev, or both,  respectively.
              The currently recognized type is marked by text "(current)".

       Settings for result writing:

       Rock  Ridge  info  will  be  generated  by default.  ACLs will be written according to the
       setting of command -acl.

       -joliet "on"|"off"
              If enabled by "on", generate Joliet tree additional to ISO 9660 + Rock Ridge tree.

       -hfsplus "on"|"off"
              If enabled by "on", generate a HFS+ filesystem inside the ISO 9660 image  and  mark
              it by Apple Partition Map (APM) entries in the System Area, the first 32 KiB of the
              image.
              This may collide with data submitted by  -boot_image  system_area=.   The  first  8
              bytes  of  the  System Area get overwritten by { 0x45, 0x52, 0x08 0x00, 0xeb, 0x02,
              0xff, 0xff } which can be executed as x86 machine code  without  negative  effects.
              So if an MBR gets combined with this feature, then its first 8 bytes should contain
              no essential commands.
              The next blocks of 2 KiB in the System Area will be occupied by APM  entries.   The
              first one covers the part of the ISO image before the HFS+ filesystem metadata. The
              second one marks the range from HFS+ metadata to the end of file content  data.  If
              more  ISO  image  data  follow,  then  a third partition entry gets produced. Other
              features of xorriso might cause the need for more APM entries.
              The  HFS+  filesystem  is  not  suitable  for  add-on  sessions  produced  by   the
              multi-session method of growing. An existing ISO image may nevertheless be the base
              for a new image produced by the method of modifying.  If -hfsplus is  enabled  when
              -indev  or -dev gets executed, then AAIP attributes get loaded from the input image
              and checked for information about HFS creator, filetype,  or  blessing.  If  found,
              then  they  get enabled as settings for the next image production.  Therefore it is
              advisable to perform -hfsplus "on" before -indev or -dev.
              Information about HFS creator, type,  and  blessings  gets  stored  by  xorriso  if
              -hfsplus  is  enabled  at  -commit  time.  It  is  stored  as copy outside the HFS+
              partition, but rather along with the Rock Ridge information.  xorriso does not read
              any information from the HFS+ meta data.
              Be  aware  that  HFS+  is  case-insensitive  although it can record file names with
              upper-case and lower-case letters. Therefore, file names from the iso_rr name  tree
              may  collide  in  the  HFS+  name  tree.  In  this  case they get changed by adding
              underscore characters and counting numbers. In case of very long names, it might be
              necessary to map them to "MANGLED_...".

       -rockridge "on"|"off"
              Mode  "off"  disables  production  of  Rock Ridge information for the ISO 9660 file
              objects. The multi-session capabilities  of  xorriso  depend  much  on  the  naming
              fidelity  of  Rock  Ridge.  So  it  is strongly discouraged to deviate from default
              setting "on".

       -compliance rule[:rule...]
              Adjust the compliance to specifications of ISO 9660/ECMA-119 and  its  contemporary
              extensions.  In some cases it is worth to deviate a bit in order to circumvent bugs
              of the intended reader system or to get unofficial extra features.
              There are several adjustable rules which have a keyword each. If they are mentioned
              with  this command then their rule gets added to the relaxation list. This list can
              be erased by rules "strict" or "clear". It can be reset to  its  start  setting  by
              "default".  All  of  the  following relaxation rules can be revoked individually by
              appending "_off". Like "deep_paths_off".
              Rule keywords are:
              "iso_9660_level="number chooses level 1 with ECMA-119 names of  the  form  8.3  and
              -file_size_limit  <= 4g - 1, or level 2 with ECMA-119 names up to length 32 and the
              same -file_size_limit, or  level  3  with  ECMA-119  names  up  to  length  32  and
              -file_size_limit >= 400g -200k. If necessary -file_size_limit gets adjusted.
              "allow_dir_id_ext" allows ECMA-119 names of directories to have a name extension as
              with other file types. It does not force dots and  it  omits  the  version  number,
              though. This is a bad tradition of mkisofs which violates ECMA-119.  Especially ISO
              level 1 only allows 8 characters in a directory name and not 8.3.
              "omit_version" does not add versions (";1") to ECMA-119 and Joliet file names.
              "only_iso_version" does not add versions (";1") to Joliet file names.
              "deep_paths" allows ECMA-119 file paths deeper than 8 levels.
              "long_paths" allows ECMA-119 file paths longer than 255 characters.
              "long_names" allows up to 37 characters with ECMA-119 file names.
              "no_force_dots" does not add a dot to ECMA-119 file names which have none.
              "no_j_force_dots" does not add a dot to Joliet file names which have none.
              "lowercase" allows lowercase characters in ECMA-119 file names.
              "7bit_ascii" allows nearly all  7-bit  characters  in  ECMA-119  file  names.   Not
              allowed  are 0x0 and '/'. If not "lowercase" is enabled, then lowercase letters get
              converted to uppercase.
              "full_ascii" allows all 8-bit characters except 0x0 and '/' in ECMA-119 file names.
              "untranslated_names" might be dangerous for inadverted reader programs  which  rely
              on  the  restriction  to  at  most 37 characters in ECMA-119 file names.  This rule
              allows ECMA-119 file names up to 96 characters with no character conversion.  If  a
              file name has more characters, then image production will fail deliberately.
              "untranslated_name_len="number  enables untranslated_names with a smaller limit for
              the length of file names. 0 disables this feature, -1 chooses maximum length limit,
              numbers larger than 0 give the desired length limit.
              "joliet_long_names" allows Joliet leaf names up to 103 characters rather than 64.
              "joliet_long_paths" allows Joliet paths longer than 240 characters.
              "joliet_utf16"  encodes Joliet names in UTF-16BE rather than UCS-2.  The difference
              is with characters which are not present in UCS-2 and get encoded in  UTF-16  by  2
              words of 16 bit each.  Both words then stem from a reserved subset of UCS-2.
              "always_gmt" stores timestamps in GMT representation with timezone 0.
              "rec_mtime"  records with non-RockRidge directory entries the disk file's mtime and
              not the creation time of the image. This applies to the ECMA-119  tree  (plain  ISO
              9660), to Joliet, and to ISO 9660:1999. "rec_time" is default. If disabled, it gets
              automatically re-enabled by -as mkisofs emulation when a pathspec is encountered.
              "new_rr" uses Rock Ridge version 1.12 (suitable for GNU/Linux  but  not  for  older
              FreeBSD  or for Solaris). This implies "aaip_susp_1_10_off" which may be changed by
              subsequent "aaip_susp_1_10".
              Default is  "old_rr"  which  uses  Rock  Ridge  version  1.10.  This  implies  also
              "aaip_susp_1_10" which may be changed by subsequent "aaip_susp_1_10_off".
              "aaip_susp_1_10"  allows  AAIP to be written as unofficial extension of RRIP rather
              than as official extension under SUSP-1.12.
              "no_emul_toc" saves 64 kB with the first session on overwriteable media  but  makes
              the image incapable of displaying its session history.
              "iso_9660_1999"  causes the production of an additional directory tree compliant to
              ISO 9660:1999. It can record long filenames for readers  which  do  not  understand
              Rock Ridge.
              "old_empty" uses the old way of of giving block addresses in the range of [0,31] to
              files with no own data content. The new way is to have a dedicated block  to  which
              all such files will point.
              Default setting is
               "clear:only_iso_version:deep_paths:long_paths:no_j_force_dots:
               always_gmt:old_rr".
              Note:  The term "ECMA-119 name" means the plain ISO 9660 names and attributes which
              get visible if the reader ignores Rock Ridge.

       -rr_reloc_dir name
              Specify the name of the relocation directory in which deep directory subtrees shall
              be  placed  if  -compliance is set to "deep_paths_off" or "long_paths_off".  A deep
              directory is one that has a chain of 8 parent directories  (including  root)  above
              itself,  or  one  that  contains  a  file  with  an  ECMA-119 path of more than 255
              characters.
              The overall directory tree will appear originally deep  when  interpreted  as  Rock
              Ridge  tree.  It  will  appear  as  re-arranged  if  only  ECMA-119  information is
              considered.
              The default relocation directory is the root directory. By giving a non-empty  name
              with  -rr_reloc_dir,  a directory in the root directory may get this role.  If that
              directory does not already exist at -commit time, then  it  will  get  created  and
              marked  for Rock Ridge as relocation artefact. At least on GNU/Linux it will not be
              displayed in mounted Rock Ridge images.
              The name must not contain a '/' character and must not be longer than 255 bytes.

       -volid text
              Specify the volume ID, which most operating systems will consider to be the  volume
              name of the image or medium.
              xorriso  accepts any text up to 32 characters, but according to rarely obeyed specs
              stricter rules apply:
              ECMA-119 demands ASCII characters out of [A-Z0-9_]. Like:
                "IMAGE_23"
              Joliet allows 16 UCS-2 characters. Like:
                "Windows name"
              Be aware that the volume id might get used automatically as the name of  the  mount
              point when the medium is inserted into a playful computer system.
              If  an ISO image gets loaded while the volume ID is set to default "ISOIMAGE" or to
              "", then the volume ID of the loaded image will become the effective volume id  for
              the  next  write  run.  But as soon as command -volid is performed afterwards, this
              pending ID is overridden by the new setting.
              Consider this when setting -volid "ISOIMAGE"  before  executing  -dev,  -indev,  or
              -rollback.  If you insist in -volid "ISOIMAGE", set it again after those commands.

       -volset_id text
              Set  the volume set ID string to be written with the next -commit.  Permissible are
              up to 128 characters. This setting gets overridden by image loading.

       -publisher text
              Set the publisher ID string to be written with the next -commit. This may  identify
              the  person  or organisation who specified what shall be recorded.  Permissible are
              up to 128 characters. This setting gets overridden by image loading.

       -application_id text
              Set the application ID string to  be  written  with  the  next  -commit.  This  may
              identify the specification of how the data are recorded.  Permissible are up to 128
              characters. This setting gets overridden by image loading.
              The special text "@xorriso@" gets converted to the ID string of  xorriso  which  is
              normally  written  as -preparer_id. It is a wrong tradition to write the program ID
              as -application_id.

       -system_id text
              Set the system ID string to be written with the next -commit. This may identify the
              system  which  can  recognize  and act upon the content of the System Area in image
              blocks 0 to 15.  Permissible are up to 32 characters. This setting gets  overridden
              by image loading.

       -volume_date type timestring
              Set  one  of  the  four overall timestamps for subsequent image writing.  Available
              types are:
              "c"  time when the volume was created.
              "m"  time when volume was last modified.
              "x"  time when the information in the volume expires.
              "f"  time since when the volume is effectively valid.
              "all_file_dates"  sets mtime, atime, and ctime of all files and directories to  the
              given  time.  If the timestring is "set_to_mtime", then the atime and ctime of each
              file and directory get set to the value found in their mtime.
              These actions stay delayed until actual ISO production begins.  Up to then they can
              be revoked by "all_file_dates" with empty timestring or timestring "default".
              The  timestamps  of  the  El Torito boot catalog file get refreshed when the ISO is
              produced. They can be influenced by "uuid".
              "uuid"  sets a timestring that overrides "c" and "m" times literally and  sets  the
              time  of  the  El  Torito boot catalog.  It must consist of 16 decimal digits which
              form YYYYMMDDhhmmsscc, with YYYY between 1970 and 2999. Time zone is  GMT.   It  is
              supposed to match this GRUB line:
               search --fs-uuid --set YYYY-MM-DD-hh-mm-ss-cc
              E.g. 2010040711405800 is 7 Apr 2010 11:40:58 (+0 centiseconds).
              Timestrings  for the other types may be given as with command -alter_date.  Some of
              them are prone to timezone computations. The timestrings "default" or  "overridden"
              cause  default  settings: "c" and "m" will show the current time of image creation.
              "x" and "f" will be marked as insignificant.  "uuid" will be deactivated.
              At -commit time, some timestamps get  set  to  the  maximum  value  of  effectively
              written  volume  creation  and  modification  time:  El  Torito  boot catalog, HFS+
              superblock, ECMA-119 file modification time  if  -compliance  "no_rec_mtime".   The
              isohybrid  MBR  id is computed from "uuid" if given, else from the effective volume
              modification date.

       -copyright_file text
              Set the copyright file name to be written with the next -commit. This should be the
              ISO  9660  path  of  a  file  in  the  image  which contains a copyright statement.
              Permissible are up to 37 characters. This setting gets overridden by image loading.

       -abstract_file text
              Set the abstract file name to be written with the next -commit. This should be  the
              ISO 9660 path of a file in the image which contains an abstract statement about the
              image content.  Permissible are up to 37 characters. This setting  gets  overridden
              by image loading.

       -biblio_file text
              Set  the  biblio  file name to be written with the next -commit. This should be the
              ISO 9660 path of  a  file  in  the  image  which  contains  bibliographic  records.
              Permissible are up to 37 characters. This setting gets overridden by image loading.

       -preparer_id
              Set  the  preparer ID string to be written with the next -commit. This may identify
              the person or other entity which controls the preparation of the data  which  shall
              be  recorded.  Normally  this  should be the ID of xorriso and not of the person or
              program which operates xorriso.  Please avoid to change it.  Permissible are up  to
              128 characters.
              The  special  text  "@xorriso@" gets converted to the ID string of xorriso which is
              default at program startup.
              Unlike other ID strings, this setting is not influenced by image loading.

       -application_use character|0xXY|disk_path
              Specify the content of the Application Use field which can take at most 512 bytes.
              If the parameter of this command is empty,  then  the  field  is  filled  with  512
              0-bytes.  If  it  is  a  single  character, then it gets repeated 512 times.  If it
              begins by "0x" followed by two hex digits [0-9a-fA-F], then the digits are read  as
              byte value which gets repeated 512 times.
              Any other parameter text is used as disk_path to open a data file and to read up to
              512 bytes from it. If the file is smaller than 512 bytes, then the remaining  bytes
              in the field get set to binary 0.
              This setting is not influenced by image loading.

       -out_charset character_set_name
              Set  the character set to which file names get converted when writing an image. See
              paragraph "Character sets" for more explanations.  When loading the  written  image
              after -commit the setting of -out_charset will be copied to -in_charset.

       -uid uid
              User id to be used for all files when the new ISO tree gets written to media.

       -gid gid
              Group id to be used for all files when the new ISO tree gets written to media.

       -zisofs option[:options]
              Set  global  parameters  for zisofs compression. This data format is recognized and
              transparently uncompressed by some Linux kernels. It is to be applied  via  command
              -set_filter with built-in filter "--zisofs".  Parameters are:
               "level="[0-9] zlib compression: 0=none, 1=fast,..., 9=slow
               "block_size="32k|64k|128k size of compression blocks
               "by_magic=on"  enables  an  expensive  test  at image generation time which checks
              files from disk whether  they  already  are  zisofs  compressed,  e.g.  by  program
              mkzftree.
               "default" same as "level=6:block_size=32k:by_magic=off"

       -speed code|number[k|m|c|d|b]
              Set  the  burn speed. Default is "max" (or "0") = maximum speed as announced by the
              drive.  Further special speed codes are:
              "min" (or "-1") selects minimum speed as announced by the drive.
              "none" avoids to send a speed setting command to the drive before burning begins.
              Speed can be given in media dependent numbers or as a desired throughput per second
              in  MMC  compliant  kB  (= 1000) or MB (= 1000 kB). Media x-speed factor can be set
              explicitly by "c" for CD, "d" for DVD, "b" for BD, "x" is optional.
              Example speeds:
               706k = 706kB/s = 4c = 4xCD
               5540k = 5540kB/s = 4d = 4xDVD
              If there is no hint about the speed unit attached, then the medium in  the  -outdev
              will decide. Default unit is CD = 176.4k.
              MMC  drives usually activate their own idea of speed and take the speed value given
              by the burn program only as upper limit for their own decision.

       -stream_recording "on"|"off"|"full"|"data"|number
              Setting "on" tries to circumvent the management of defects on  DVD-RAM,  BD-RE,  or
              BD-R.  Defect  management  keeps  partly damaged media usable. But it reduces write
              speed to half nominal speed even if the medium is in perfect shape.  For  the  case
              of flawless media, one may use -stream_recording "on" to get full speed.
              "full"  tries  full  speed  with  all write operations, whereas "on" does this only
              above byte address 32s. One may give a number of at least 16s in order  to  set  an
              own address limit.
              "data" causes full speed to start when superblock and directory entries are written
              and writing of file content blocks begins.

       -dvd_obs "default"|"32k"|"64k"
              GNU/Linux specific: Set the number of bytes  to  be  transmitted  with  each  write
              operation  to  DVD  or  BD media. A number of 64 KB may improve throughput with bus
              systems which show latency problems. The default depends on media type, on  command
              -stream_recording , and on compile time options.

       -modesty_on_drive parameter[:parameters]
              Control  whether  the  drive  buffer  shall be kept from getting completely filled.
              Parameter "on" (or "1") keeps the program from trying to write to the burner  drive
              while  its  buffer  is in danger to be filled over a given limit.  If this limit is
              exceeded then the  program  will  wait  until  the  filling  reaches  a  given  low
              percentage value.
              This  can ease the load on operating system and drive controller and thus help with
              achieving better input  bandwidth  if  disk  and  burner  are  not  on  independent
              controllers  (like  hda  and  hdb).  It  may  also help with throughput problems of
              simultaneous burns on different burners with Linux kernels like 3.16,  if  one  has
              reason  not  to  fix  the  problem  by -scsi_dev_family "sg".  On the other hand it
              increases the risk of buffer underflow and thus reduced write speed.
              Some burners are not suitable because they report buffer fill with granularity  too
              coarse  in size or time, or expect their buffer to be filled to the top before they
              go to full speed.
              Parameters "off" or "0" disable this feature.
              The  threshold  for  beginning  to  wait  is  given  by  parameter  "max_percent=".
              Parameter   "min_percent="   defines   the  threshold  for  resuming  transmission.
              Percentages are permissible in the range of  25  to  100.  Numbers  in  this  range
              without a prepended name are interpreted as "on:min_percent=".
              E.g.: -modesty_on_drive 75
              The optimal values depend on the buffer behavior of the drive.
              Parameter  "timeout_sec="  defines  after  which  time  of unsuccessful waiting the
              modesty shall be disabled because it does not work.
              Parameter "min_usec=" defines the initial sleeping period in microseconds.  If  the
              drive  buffer  appears  to be too full for sending more data, the program will wait
              the given time and inquire the buffer fill state again.  If repeated inquiry  shows
              not  enough  free  space, the sleep time will slowly be increased to what parameter
              "max_usec=" defines.
              Parameters,  which  are  not  mentioned  with  a  -modesty_on_drive  command,  stay
              unchanged.  Default is:
                -modesty_on_drive off:min_percent=90:max_percent=95:
                timeout_sec=120:min_usec=5000:max_usec=25000

       -use_immed_bit "on"|"off"|"default"
              Control whether several long lasting SCSI commands shall be executed with the Immed
              bit, which makes the commands end early while the drive operation  is  still  going
              on.  xorriso  then inquires progress indication until the drive reports to be ready
              again. If this feature is turned off, then blanking and  formatting  will  show  no
              progress indication.
              It  may  depend  on  the operating system whether -use_immed_bit is set to "off" by
              default. Command -status will tell by appending "/on" or  "/off"  if  a  drive  has
              already  been  acquired  and -use_immed_bit is currently set to "default".  Command
              -use_immed_bit tolerates and ignores such appended text.

       -stdio_sync "on"|"off"|"end"|number
              Set the number of bytes after which to force output to stdio: pseudo drives.   This
              forcing  keeps  the  memory  from  being clogged with lots of pending data for slow
              devices. Default "on" is the same as "16m".   Forced  output  can  be  disabled  by
              "off",  or  be delayed by "end" until all data are produced. If a number is chosen,
              then it must be at least 64k.

       -dummy "on"|"off"
              If "on" then simulate burning or refuse with FAILURE  event  if  no  simulation  is
              possible, do neither blank nor format.

       -fs number["k"|"m"]
              Set  the  size  of  the  fifo buffer which smoothens the data stream from ISO image
              generation to media burning. Default is 4 MiB, minimum 64 kiB, maximum 1 GiB.   The
              number may be followed by letter "k" or "m" which means unit is kiB (= 1024) or MiB
              (= 1024 kiB).

       -close "on"|"off"|"as_needed"
              If -close is set to "on" then mark the written medium as not appendable  any  more.
              This will have no effect on overwritable media types.  Setting "on" is the contrary
              of cdrecord option -multi, and is one aspect of growisofs option -dvd-compat.
              If set to "off" then keep the medium writable for an appended session.
              If set to "as_needed" then use "on" only if "off" is predicted  to  fail  with  the
              given medium and its state.
              Not  all  drives correctly recognize fast-blanked DVD-RW which need "on".  If there
              is well founded suspicion that a burn run failed due to -close "off",  then  -close
              "as_needed" causes a re-try with "on".
              Note  that  emulation  command  -as  "cdrecord"  temporarily  overrides the current
              setting of -close by its own default -close "on" if its option -multi is missing.

       -write_type "auto"|"tao"|"sao/dao"
              Set the write type for the next burn run. "auto" will  select  SAO  with  blank  CD
              media,  DAO  with  blank  DVD-R[W]  if  -close  is "on", and elsewise CD TAO or the
              equivalent write type of the particular DVD/BD  media.   Choosing  TAO  or  SAO/DAO
              explicitly  might  cause  the  burn  run  to  fail if the desired write type is not
              possible with the given media state.

       -padding number["k"|"m"]|"included"|"appended"
              Append the given number of extra bytes to the image stream.  This is a  traditional
              remedy  for  a  traditional  bug  in  block device read drivers. Needed only for CD
              recordings in TAO mode.  Since one can hardly predict on what media an image  might
              end up, xorriso adds the traditional 300k of padding by default to all images.
              For images which will never get to a CD it is safe to use -padding 0 .
              Normally  padding  is  not  written as part of the ISO image but appended after the
              image end. This is -padding mode "appended".
              Emulation command -as "mkisofs" and command -jigdo cause padding to be  written  as
              part of the image.  The same effect is achieved by -padding mode "included".

       Bootable ISO images:

       Contrary  to  published  specifications many BIOSes will load an El Torito record from the
       first session on media and not from the last one, which  gets  mounted  by  default.  This
       makes  no  problems with overwriteable media, because they appear to inadverted readers as
       one single session.
       But with multi-session media CD-R[W], DVD-R[W], DVD+R, it implies that the whole  bootable
       system  has  to reside already in the first session and that the last session still has to
       bear all files which the booted system expects after mounting the ISO image.
       If a boot image from ISOLINUX or GRUB is known to be present on media then it  is  advised
       to  patch  it  when  a  follow-up  session  gets  written.  But one should not rely on the
       capability to influence the bootability of the existing sessions, unless  one  can  assume
       overwriteable media.
       Normally  the  boot  images  are  data  files  inside  the ISO filesystem. By special path
       "--interval:appended_partition_NNN:all::"  it  is  possible  to  refer  to   an   appended
       partition.  The  number  NNN  gives  the  partition  number as used with the corresponding
       command -append_partition.  E.g.:
         -append_partition 2 0xef /tmp/efi.img
         -boot_image any efi_path=--interval:appended_partition_2:all::
       There are booting mechanisms which do not use an El Torito record but rather start at  the
       first bytes of the image: PC-BIOS MBR or EFI GPT for hard-disk-like devices, APM partition
       entries for Macs which expect HFS+ boot images, MIPS Volume Header for old SGI  computers,
       DEC  Boot  Block  for  old  MIPS DECstation, SUN Disk Label for SPARC machines, HP-PA boot
       sector for HP PA-RISC machines, DEC Alpha SRM boot sector for old DEC Alpha machines.

       Several of the following commands expect disk paths as input but also  accept  description
       strings for the libisofs interval reader, which is able to cut out data from disk files or
       -indev and to  zeroize  parts  of  the  content:  command  -append_partition,  boot  specs
       system_area=, grub2_mbr=, prep_boot_part=, efi_boot_part=.
       The description string consists of the following components, separated by colon ':'
         "--interval:"Flags":"Interval":"Zeroizers":"Source
       The  component  "--interval"  states  that  this  is  not  a plain disk path but rather an
       interval  reader  description  string.   The  component   Flags   modifies   the   further
       interpretation:
       "local_fs" demands to read from a file depicted by the path in Source.
       "imported_iso" demands to read from the -indev. This works only if -outdev is not the same
       as -indev. The Source component is ignored.
       "appended_partition_NNN" with a decimal number NNN works only  for  -boot_image  bootspecs
       which  announce  El  Torito  boot image paths: bin_path=, efi_path=.  The number gives the
       partition number as used with the corresponding option -append_partition.
       The component Interval consists of two byte address numbers separated  by a "-" character.
       E.g. "0-429" means to read bytes 0 to 429.
       The  component  Zeroizers  consists  of zero or more comma separated strings.  They define
       which part of the read data to zeroize. Byte  number  0  means  the  byte  read  from  the
       Interval start address.  Each string may be one of:
       "zero_mbrpt"  demands to zeroize the MBR partition table if bytes 510 and 511 bear the MBR
       signature 0x55 0xaa.
       "zero_gpt" demands to check for a GPT header in bytes 512 to 1023, to zeroize it  and  its
       partition table blocks.
       "zero_apm" demands to check for an APM block 0 and to zeroize its partition table blocks.
       Start_byte"-"End_byte   demands  to  zeroize  the  read-in  bytes  beginning  with  number
       Start_byte and ending after End_byte.
       The component Source is the  file  path  with  flag  "local_fs",  and  ignored  with  flag
       "imported_iso".
       Byte  numbers  may  be  scaled  by a suffix out of {k,m,g,t,s,d} meaning multiplication by
       {1024, 1024k, 1024m, 1024g, 2048, 512}. A scaled value end number depicts the last byte of
       the scaled range.
       E.g. "0d-0d" is "0-511".
       Examples:
         "local_fs:0-32767:zero_mbrpt,zero_gpt,440-443:/tmp/template.iso"
         "imported_iso:45056d-47103d::"

       -boot_image "any"|"isolinux"|"grub"
                   "discard"|"keep"|"patch"|"replay"|"show_status"|
                   bootspec|"next"
              Define the equipment of the emerging filesystem with boot entry points.
              With  systems  which  boot  via BIOS or EFI this is a set of El Torito boot images,
              possibly MBR boot code, and possibly partition tables of type  MBR,  GPT,  or  APM.
              Such file sets get produced by boot loader systems like ISOLINUX or GRUB.

              Each  -boot_image  command  has  two  parameters:  type  and setting. More than one
              -boot_image command may be used to define the handling of one or more boot  images.
              Sequence matters.
              Types  isolinux  and  grub  care  for  known  peculiarities.   Type  any  makes  no
              assumptions about the origin of the boot images.

              When loading an ISO filesystem, system area and El Torito boot images  get  loaded,
              too. The default behavior is not to write loaded El Torito boot images and to write
              the loaded system area content without alterations.
              discard gives up the El Torito  boot  catalog  and  its  boot  images.   regardless
              whether  loaded  from  an  ISO  filesystem or defined by commands.  Any BIOS or EFI
              related boot options get revoked.   Nevertheless,  loaded  system  area  data  stay
              valid. If desired, they have to be erased by
               -boot_image any system_area=/dev/zero
              keep keeps or copies El Torito boot images unaltered and writes a new catalog.
              patch  applies  patching  to  existing El Torito boot images if they seem to bear a
              boot info table.
              A boot info table needs to be patched when the boot  image  gets  newly  introduced
              into  the  ISO image or if an existing image gets relocated.  This is automatically
              done if type "isolinux" or "grub" is given, but not with "any".
              If patching is enabled, then boot images from previous  sessions  will  be  checked
              whether they seem to bear a boot info table. If not, then they stay unpatched. This
              check is not infallible. So if you do know that the images need  no  patching,  use
              "any" "keep".  "grub" "patch" will not patch EFI images (platform_id=0xef).
              replay  is  a  more modern version of "patch", which not only cares for existing El
              Torito boot equipment but also for the recognizable boot provisions in  the  System
              Area.  It  discards  any  existing  -boot_image  setting  and executes the commands
              proposed by command -report_el_torito "cmd".
              This action will only succeed if the  file  objects  mentioned  in  the  output  of
              command  -report_el_torito  "cmd" are still available. Do not remove or rename boot
              image files after -indev.
              Drop unknown El Torito:  -boot_image "any" "discard"
              Maintain recognizable stuff:  -boot_image "any" "replay"
              El Torito only for GRUB:  -boot_image "grub" "patch"
              El Torito only for ISOLINUX:  -boot_image "isolinux" "patch"
              show_status will print what is  known  about  the  loaded  boot  images  and  their
              designated fate.

              A  bootspec is a word of the form name=value. It is used to describe the parameters
              of a boot feature.  The names "dir",  "bin_path",  "efi_path"  lead  to  El  Torito
              bootable  images.   Name  "system_area" activates a given file as MBR or other disk
              header.
              On all media types this is possible within the first session. In  further  sessions
              an  existing  boot  image can get replaced by a new one, but depending on the media
              type this may have few effect at boot time. See above.
              El Torito boot images have to be added to the ISO  image  by  normal  means  (image
              loading,  -map,  -add,  ...). In case of ISOLINUX the files should reside either in
              ISO image directory /isolinux or in /boot/isolinux .  In that case it  suffices  to
              use as bootspec the text "dir=/isolinux" or "dir=/boot/isolinux". E.g.:
               -boot_image isolinux dir=/boot/isolinux
              which bundles these individual settings:
               -boot_image isolinux bin_path=/boot/isolinux/isolinux.bin
               -boot_image isolinux cat_path=/boot/isolinux/boot.cat
               -boot_image isolinux load_size=2048
               -boot_image any boot_info_table=on
              An  El  Torito  boot  catalog  file  gets  inserted into the ISO image with address
              cat_path= with the first -boot_image "any"  "next"  or  at  -commit  time.   It  is
              subject  to  normal  -overwrite and -reassure processing if there is already a file
              with the same name.  The catalog lists the boot images and  is  read  by  the  boot
              facility  to choose one of the boot images. But it is not necessary that it appears
              in the directory tree at all. One may hide it in all trees by cat_hidden=on.  Other
              possible  values  are  "iso_rr",  "joliet",  "hfsplus", and the default "off".  The
              timestamps of the  boot  catalog  file  are  refreshed  at  commit  time.   Command
              -volume_date "uuid" can be used to set their value.
              bin_path=  depicts  an  El  Torito boot image file, a binary program which is to be
              started by the hardware boot facility (e.g. the BIOS) at boot time.
              efi_path= depicts an El Torito boot image file that is ready for EFI booting.  This
              is  normally a FAT filesystem image not larger than 65535 blocks of 512 bytes (= 32
              MiB - 512).  Its load_size is determined automatically, no  boot  info  table  gets
              written, no boot medium gets emulated, platform_id is 0xef.
              emul_type=  can be one of "no_emulation", "hard_disk", "diskette".  It controls the
              boot medium emulation code of a boot image.  The default "no_emulation" is suitable
              for ISOLINUX, GRUB, FreeBSD cdboot.
              load_size=  is  a  value  which  depends  on the boot image.  Default is 2048 which
              matches the expectations of most boot images.  The special value "full"  means  the
              full size of the boot image file rounded up to a multiple of 2048 bytes. Maximum is
              33,552,384 bytes.
              boot_info_table=on causes address patching to bytes 8 to 63 of the boot image which
              is given by "any" "bin_path=".  "boot_info_table=off" disables this patching.
              grub2_boot_info=on  causes address patching to byte 2548 of the boot image which is
              given by "any" "bin_path=".  The address is written as 64 bit little-endian number.
              It  is  the  2KB block address of the boot image content, multiplied by 4, and then
              incremented by 5.  "grub2_boot_info=off" disables this patching.
              platform_id= defines by a hexadecimal or decimal number the Platform ID of the boot
              image.  "0x00"  is  80x86  PC-BIOS, "0x01" is PowerPC, "0x02" is Mac, "0xef" is EFI
              (decimal "239").
              id_string=text|56_hexdigits defines the ID string of the boot catalog section where
              the  boot  image will be listed. If the value consists of 56 characters [0-9A-Fa-f]
              then it is converted into 28 bytes, else the first  28  characters  become  the  ID
              string.   The ID string of the first boot image becomes the overall catalog ID.  It
              is limited to 24 characters. Other id_strings become section IDs.
              sel_crit=hexdigits defines the Selection Criteria of the  boot  image.   Up  to  20
              bytes  get  read from the given characters [0-9A-Fa-f].  They get attributed to the
              boot image entry in the catalog.
              next ends the definition of a boot image and  starts  a  new  one.   Any  following
              -bootimage  bootspecs  will affect the new image.  The first "next" discards loaded
              boot images and their catalog.
              system_area=disk_path copies at most 32768 bytes from the given disk  file  to  the
              very  start  of  the  ISO image.  This System Area is reserved for system dependent
              boot software, e.g. an MBR which can be used to boot from USB stick or hard disk.
              Other than an El Torito boot image, the file disk_path needs not to be added to the
              ISO image.
              -boot_image  isolinux system_area= implies "partition_table=on".  In this case, the
              disk path should lead to one of the SYSLINUX files isohdp[fp]x*.bin or  to  a  file
              which  was  derived  from  one of those files.  E.g. to the first 512 bytes from an
              ISOLINUX isohybrid ISO image.
              In this case, El Torito boot images (dir=, bin_path=, efi_path=) may  be  augmented
              by isolinux partition_entry=gpt_basdat or isolinux partition_entry=gpt_hfsplus, and
              by isolinux partition_entry=apm_hfsplus.  The boot image will then be mentioned  in
              GPT  as  Basic Data or GPT HFS+ partition, and in APM as HFS+ partition.  The first
              three GPT partitions will also be marked by MBR partitions.
              In multi-session situations the existing System Area is preserved by  default.   In
              in  this  case,  the  special  disk_path  "."  prevents  reading of a disk file but
              nevertheless causes adjustments in the loaded system area  data.  Such  adjustments
              may get ordered by -boot_image commands.
              -boot_image  any  gpt_disk_guid=value  controls whether an emerging GPT shall get a
              randomly generated disk GUID or whether the GUID is supplied by  the  user.   Value
              "random"  is default. Value "volume_date_uuid" produces a low quality GUID from the
              value set by -volume_date "uuid".
              A string of 32 hex digits, or a RFC 4122 compliant GUID string may be used  to  set
              the  disk  GUID  directly. UEFI prescribes the first three components of a RFC 4122
              GUID string to be byte-swapped in the binary representation:
              E.g.           gpt_disk_guid=2303cd2a-73c7-424a-a298-25632da7f446            equals
              gpt_disk_guid=2acd0323c7734a42a29825632da7f446
              The partition GUIDs get generated by minimally varying the disk GUID.
              -boot_image     any    part_like_isohybrid=on    enables    -boot_image    isolinux
              partition_entry= even if no -boot_image isolinux system_area=  is  given.   No  MBR
              partition   of  type 0xee emerges, even if GPT gets produced.  Gaps between GPT and
              APM partitions will not be filled by  more  partitions.   Appended  partitions  get
              mentioned in APM if other APM partitions emerge.
              -boot_image  any  iso_mbr_part_type=number  sets  the  partition  type  of  the MBR
              partition which represents the ISO or at least protects it.  Number may be 0x00  to
              0xff.  The  text "default" re-enables the default types of the various occasions to
              create an ISO MBR partition.
              This is without effect if no such partition emerges by other  settings  or  if  the
              partition  type  is prescribed mandatorily like 0xee for GPT protective MBR or 0x96
              for CHRP.
              grub2_mbr=disk_path works like "any"  system_area=  with  additional  patching  for
              modern GRUB MBRs. The content start address of the first boot image is converted to
              a count of 512 byte blocks, and an offset of 4 is added.  The result is written  as
              64 bit little-endian number to byte address 0x1b0.
              This  feature  can  be  revoked  either  by  grub2_mbr= with empty disk path, or by
              submitting a disk_path via system_area=.
              partition_table=on causes a simple partition table to be written into bytes 446  to
              511 of the System Area.
              With  type  "isolinux" it shows a partition that begins at byte 0 and it causes the
              LBA of the first boot image to be written into the MBR. For the first session  this
              works only if also "system_area=" and "bin_path=" or "dir=" is given.
              With  types  "any"  and "grub" it shows a single partition which starts at byte 512
              and ends where the ISO image ends.  This works with or without system_area= or boot
              image.
              Bootspecs chrp_boot_part=, prep_boot_part=, and efi_boot_part= overwrite this entry
              in the MBR partition table.
              If types "isolinux" or "grub" are set  to  "patch",  then  "partition_table=on"  is
              activated  without  new  boot  image.   In  this case the existing System Area gets
              checked whether it bears addresses and  sizes  as  if  it  had  been  processed  by
              "partition_table=on".  If so, then those parameters get updated when the new System
              Area is written.
              Special "system_area=/dev/zero" causes 32k of NUL-bytes.  Use this  to  discard  an
              MBR which was loaded with the ISO image.
              appended_part_as=gpt  marks partitions from -append_partition in GPT rather than in
              MBR. In this case the MBR shows a single partition of type 0xee  which  covers  the
              whole output data.
              appended_part_as=mbr  is the default. Appended partitions get marked in GPT only if
              GPT is produced because of  other  settings.   If  given  explicitly,  this  clears
              setting "gpt" and "apm". Nevertheless "apm" may be added to "mbr".
              appended_part_as=apm marks partitions from -append_partition in APM additionally to
              "mbr" or "gpt".
              By default, appended partitions get marked in APM only if APM is  produced  because
              of other options together with part_like_isohybrid="on".
              chrp_boot_part=on causes a single partition in MBR which covers the whole ISO image
              and has type 0x96. This is not compatible with any other feature that produces  MBR
              partition entries. It makes GPT unrecognizable.
              prep_boot_part=disk_path  inserts  the  content  of  a data file into the image and
              marks it by an MBR partition of type 0x41. The parts of the ISO  image  before  and
              after  this  partition will be covered by further MBR partitions.  The data file is
              supposed to contain ELF executable code.
              efi_boot_part=disk_path inserts the content of a data file into the image and marks
              it  by  a  GPT partition. If not chrp_boot_part=on, then the first partition in MBR
              will have type 0xee to announce the presence of GPT.  The data file is supposed  to
              contain a FAT filesystem.
              Instead  of a disk_path, the word --efi-boot-image may be given.  It exposes in GPT
              the content of the first El Torito EFI boot image as EFI system partition. EFI boot
              images  are  introduced  by bootspec efi_path=.  The affected EFI boot image cannot
              show up in HFS+ because it is stored outside the HFS+ partition.
              partition_offset=2kb_block_adr causes a partition table  with  a  single  partition
              that begins at the given block address. This is counted in 2048 byte blocks, not in
              512 byte blocks. If the block address is non-zero then it must be at  least  16.  A
              non-zero  partition  offset  causes two superblocks to be generated and two sets of
              directory trees. The image is then mountable from its absolute  start  as  well  as
              from the partition start.
              The  offset  value  of an ISO image gets preserved when a new session is added.  So
              the value defined here is only in effect if a new ISO image gets written.
              partition_hd_cyl=number gives the number of heads per cylinder  for  the  partition
              table. 0 chooses a default value. Maximum is 255.
              partition_sec_hd=number  gives  the  number  of  sectors per head for the partition
              table. 0 chooses a default value. Maximum is 63.
              The product partition_sec_hd * partition_hd_cyl * 512 is  the  cylinder  size.   It
              should  be  divisible  by  2048  in  order  to make exact alignment possible.  With
              appended partitions and "appended_part_as=gpt" there is no limit for the number  of
              cylinders.  Else  there  may  be at most 1024 of them.  If the cylinder size is too
              small to stay below the limit, then  appropriate  values  of  partition_hd_cyl  are
              chosen  with  partition_sec_hd  32 or 63. If the image is larger than 8,422,686,720
              bytes, then the cylinder size constraints cannot be fulfilled for MBR.
              partition_cyl_align=mode controls image size alignment  to  an  integer  number  of
              cylinders.  It  is  prescribed  by  isohybrid  specs and it seems to please program
              fdisk. Cylinder size must be divisible by 2048.  Images larger  than  8,323,596,288
              bytes cannot be aligned in MBR partition table.
              Mode  "auto"  is  default.  Alignment  by  padding  happens  only  with  "isolinux"
              "partition_table=on".
              Mode "on" causes alignment by padding with "partition_table=on" for any type.  Mode
              "all" is like "on" but also pads up partitions from -append_partition to an aligned
              size.
              Mode "off" disables alignment for any type.
              mbr_force_bootable=mode enforces an MBR partition with  "bootable/active"  flag  if
              options  like partition_table= or grub2_mbr= indicate production of a bootable MBR.
              These options normally cause the flag to be set if there is  an  MBR  partition  of
              type  other  than  0xee  or 0xef.  If no such partition exists, then no bootflag is
              set, unless mbr_force_bootable="on" forces creation of a dummy  partition  of  type
              0x00 which covers only the first block of the ISO image.
              If  no bootable MBR is indicated and a partition gets created by -append_partition,
              then mbr_force_bootable="on" causes a bootflag like it would  do  with  a  bootable
              MBR.
              mips_path=iso_rr_path  declares  a  data  file in the image to be a MIPS Big Endian
              boot file and causes production of  a  MIPS  Big  Endian  Volume  Header.  This  is
              mutually  exclusive  with  production  of  other  boot  blocks  like  MBR.  It will
              overwrite the first 512 bytes of any data provided by system_area=.  Up to 15  boot
              files can be declared by mips_path=.
              mipsel_path=iso_rr_path  declares  a  data  file in the image to be the MIPS Little
              Endian boot file. This is mutually exclusive  with  other  boot  blocks.   It  will
              overwrite  the first 512 bytes of any data provided by system_area=.  Only a single
              boot file can be declared by mipsel_path=.
              sparc_label=text causes the production of a SUN Disk Label with the given  text  as
              ASCII  label.  Partitions  2  to 8 may be occupied by appended images.  Partition 1
              will always be the ISO image. See command -append_partition.  The first  512  bytes
              of any data provided by system_area= will be overwritten.
              grub2_sparc_core=iso_rr_path  causes the content address and size of the given file
              to be written after the SUN Disk Label. Both numbers  are  counted  in  bytes.  The
              address  is  written as 64 bit big-endian number to byte 0x228. The size is written
              as 32 bit big-endian number to byte 0x230.
              hppa_cmdline=text sets the PALO command line for HP-PA. Up to 1023  characters  are
              permitted by default. With hppa_hdrversion=4 the limit is 127.
              Note  that  the  first  five  hppa_  bootspecs  are  mandatory, if any of the hppa_
              bootspecs is used. Only hppa_hdrversion= is allowed to be missing.
              hppa_bootloader=iso_rr_path designates the given path as HP-PA bootloader file.
              hppa_kernel_32=iso_rr_path designates the given path as HP-PA 32 bit kernel file.
              hppa_kernel_64=iso_rr_path designates the given path as HP-PA 64 bit kernel file.
              hppa_ramdisk=iso_rr_path designates the given path as HP-PA RAM disk file.
              hppa_hdrversion=number chooses between PALO header version 5 (default) and  version
              4.  For the appropriate value see in PALO source code: PALOHDRVERSION.
              alpha_boot=iso_rr_path  declares  a  data file in the image to be the DEC Alpha SRM
              Secondary Bootstrap Loader and causes production of a boot sector which  points  to
              it.  This is mutually exclusive with production of other boot blocks like MBR.
              mips_discard,  sparc_discard,  hppa_discard,  alpha_discard  revoke  any  boot file
              declarations made for mips/mipsel,  sparc,  hppa,  or  alpha,  respectively.   This
              removes the ban on production of other boot blocks.
              hfsplus_serial=hexstring  sets  a string of 16 digits "0" to "9" and letters "a" to
              "f", which will be used as unique serial number of an emerging HFS+ filesystem.
              hfsplus_block_size=number sets the allocation block size to be used when  producing
              HFS+  filesystems.  Permissible  are  512, 2048, or 0.  The latter lets the program
              decide.
              apm_block_size=number sets the block size to be used when describing partitions  by
              an  Apple  Partition  Map.  Permissible  are  512,  2048, or 0. The latter lets the
              program decide.
              Note that size 512 is not compatible with production of GPT,  and  that  size  2048
              will not be mountable -t hfsplus at least by older Linux kernels.

       -append_partition partition_number type_code disk_path
              Cause  a  prepared  filesystem  image  to  be  appended  to the ISO image and to be
              described by a partition table entry in a boot block at the start of  the  emerging
              ISO  image. The partition entry will bear the size of the submitted file rounded up
              to the next multiple of 2048 bytes or to the next multiple of the cylinder size.
              Beware  of  subsequent  multi-session  runs.  The  appended  partition   will   get
              overwritten.
              Partitions may be appended with boot block type MBR and with SUN Disk Label.
              With MBR:
              partition_number  may  be  1  to  4. Number 1 will put the whole ISO image into the
              unclaimed space before partition 1. So together with  most  xorriso  MBR  features,
              number 2 would be the most natural choice.
              The  type_code  may  be  "FAT12", "FAT16", "Linux", or a hexadecimal number between
              0x00 and 0xff. Not all those numbers will yield usable results. For a list of codes
              search the Internet for "Partition Types" or run fdisk command "L".
              If  some  other  command causes the production of GPT, then the appended partitions
              will be mentioned there too.
              The disk_path must provide the necessary data  bytes  at  commit  time.   An  empty
              disk_path disables this feature for the given partition number.
              With SUN Disk Label (selected by -boot_image any sparc_label=):
              partition_number  may  be 2 to 8. Number 1 will always be the ISO image.  Partition
              start addresses are aligned to 320 KiB. The type_code does not matter. Submit 0x0.
              Partition image name "." causes the partition to become a copy of  the  next  lower
              valid one.

       Jigdo Template Extraction:

       From  man genisoimage: "Jigdo is a tool to help in the distribution of large files like CD
       and DVD images; see http://atterer.net/jigdo/ for more details. Debian  CDs  and  DVD  ISO
       images  are  published on the web in jigdo format to allow end users to download them more
       efficiently."
       xorriso can produce a .jigdo and a .template  file  together  with  a  single-session  ISO
       image.   The  .jigdo  file  contains checksums and symbolic file addresses.  The .template
       file contains the compressed ISO image with reference tags instead of the content bytes of
       the listed files.
       Input  for this process are the normal arguments for a xorriso session on a blank -outdev,
       and a .md5 file which lists those data files which may be listed in the  .jigdo  file  and
       externally  referenced  in the .template file.  Each designated file is represented in the
       .md5 file by a single text line:
       MD5 as 32 hex digits, 2 blanks, size as 12 decimal digits or blanks,  2  blanks,  symbolic
       file address
       The  file  address  in  an .md5 line has to bear the same basename as the disk_path of the
       file which it shall match. The directory path of the file address is decisive for  To=From
       mapping,  not  for file recognition.  After To=From mapping, the file address gets written
       into the .jigdo file. Jigdo  restore  tools  will  convert  these  addresses  into  really
       reachable data source addresses from which they can read.
       If  the  list  of  jigdo  parameters  is  not  empty, then xorriso will refuse to write to
       non-blank targets, it will disable multi-session emulation, and padding will be counted as
       part of the ISO image.

       -jigdo parameter_name value
              Clear  Jigdo  Template  Extraction  parameter list or add a parameter to that list.
              The alias names are the corresponding genisoimage options.  They  are  accepted  as
              parameter  names  as  well.  Especially  they  are  recognized  by  the -as mkisofs
              emulation command.
              Parameter clear with any value empties the whole list.   No  .jigdo  and  .template
              file will be produced.
              template_path  sets  the  disk_path  for  the  .template  file  with  the holed and
              compressed ISO image copy.
              Alias: -jigdo-template
              jigdo_path sets the disk_path for the .jigdo file with the checksums  and  download
              addresses for filling the holes in .template.
              Alias: -jigdo-jigdo
              md5_path sets the disk_path where to find the .md5 input file.
              Alias: -md5-list
              min_size  sets the minimum size for a data file to be listed in the .jigdo file and
              being a hole in the .template file.
              Alias: -jigdo-min-file-size
              exclude adds a regular expression pattern which will get compared with the absolute
              disk_path  of  any  data  file. A match causes the file to stay in .template in any
              case.
              Alias: -jigdo-exclude
              demand_md5 adds a regular expression pattern  which  will  get  compared  with  the
              absolute  disk_path  of  any data file that was not found in the .md5 list. A match
              causes a MISHAP event.
              Alias: -jigdo-force-md5
              mapping adds a string pair of the form To=From to the parameter list.   If  a  data
              file  gets  listed in the .jigdo file, then it is referred by the file address from
              its line in the .md5 file. This file address gets checked whether  it  begins  with
              the  From  string.  If so, then this string will be replaced by the To string and a
              ':' character, before it goes into the .jigdo file. The From string should end by a
              '/' character.
              Alias: -jigdo-map
              compression  chooses  one  of "bzip2" or "gzip" for the compression of the template
              file. The jigdo file is put out uncompressed.
              Alias: -jigdo-template-compress
              checksum_iso chooses one or more of  "md5",  "sha1",  "sha256",  "sha512"  for  the
              auxiliary  "# Image Hex" checksums in the jigdo file. The value may e.g.  look like
              "md5,sha1,sha512". Value "all" chooses all available  algorithms.   Note  that  MD5
              stays always enabled.
              Alias: -checksum_algorithm_iso
              checksum_template is like checksum_iso but for "# Template Hex".
              Alias: -checksum_algorithm_template

       Character sets:

       File  names  are  strings  of  non-zero bytes with 8 bit each. Unfortunately the same byte
       string may appear as different peculiar national characters  on  differently  nationalized
       terminals.   The  meanings  of  byte codes are defined in character sets which have names.
       Shell command iconv -l lists them.
       The file names on hard disk are assumed to be encoded by the local character set which  is
       also  used  for  the  communication  with  the  user.   Byte  codes 32 to 126 of the local
       character set must match the US-ASCII characters of the  same  code.  ISO-8859  and  UTF-8
       fulfill this demand.
       By default, xorriso uses the character set as told by shell command "locale" with argument
       "charmap". This may be influenced by environment variables LC_ALL, LC_CTYPE, or  LANG  and
       should  match the expectations of the terminal.  In some situations it may be necessary to
       set it by command -local_charset.
       Local character sets should not matter as long as only english alphanumeric characters are
       used  for file names or as long as all writers and readers of the media use the same local
       character set.  Outside these constraints it may be necessary to let xorriso convert  byte
       codes from and to other character sets.
       The  Rock  Ridge  file  names  in  ISO  filesystems are assumed to be encoded by the input
       character set.  The Rock Ridge file names which get written with ISO filesystems  will  be
       encoded by the output character set.
       The  sets  can be defined independently by commands -in_charset and -out_charset. Normally
       one will have both identical, if ever.  Other than the  local  character  set,  these  two
       character sets may deviate from US-ASCII.
       The output character sets for Joliet and HFS+ are not influenced by these commands. Joliet
       uses output character set UCS-2 or UTF-16. HFS+ uses UTF-16.
       The default output charset is the local character set of the terminal where xorriso  runs.
       So by default no conversion happens between local filesystem names and emerging Rock Ridge
       names in the image. The situation stays ambiguous  and  the  reader  has  to  riddle  what
       character set was used.
       By command -auto_charset it is possible to attribute the output charset name to the image.
       This makes the situation unambiguous. But if your terminal character set  does  not  match
       the  character  set  of the local file names, then this attribute can become plainly wrong
       and cause problems at read time.  To prevent this it is necessary  to  check  whether  the
       terminal  properly  displays  all intended filenames. Check especially the exotic national
       characters.
       To enforce recording of a particular character set name without any  conversion  at  image
       generation  time,  set  -charset  and  -local_charset  to  the  desired  name,  and enable
       -backslash_codes to avoid evil character display on your terminal.

       -charset character_set_name
              Set the character set from which to convert file names when loading an image and to
              which to convert when writing an image.

       -local_charset character_set_name
              Override  the  system  assumption of the local character set name.  If this appears
              necessary, one should consider to set -backslash_codes to "on" in  order  to  avoid
              dangerous binary codes being sent to the terminal.

       Exception processing:

       Since  the  tasks of xorriso are manifold and prone to external influence, there may arise
       the need for xorriso to report and handle problem events.
       Those events get classified when they are detected by one  of  the  software  modules  and
       forwarded  to reporting and evaluation modules which decide about reactions. Event classes
       are sorted by severity:
       "NEVER" The upper end of the severity spectrum.
       "ABORT" The program is being aborted and on its way to end.
       "FATAL" The main purpose of the run failed or an important resource failed unexpectedly.
       "FAILURE" An important part of the job could not be performed.
       "MISHAP" A FAILURE which can be tolerated during ISO image generation.
       "SORRY" A less important part of the job could not be performed.
       "WARNING" A situation is suspicious of being not intended by the user.
       "HINT" A proposal to the user how to achieve better results.
       "NOTE" A harmless information about noteworthy circumstances.
       "UPDATE" A pacifier message during long running operations.
       "DEBUG" A message which would only interest the program developers.
       "ALL" The lower end of the severity spectrum.

       -abort_on severity
              Set the severity threshold for events to abort the program.
              Useful: "NEVER", "ABORT", "FATAL", "FAILURE" , "MISHAP", "SORRY"
              It may become necessary to abort the program anyway, despite the  setting  by  this
              command. Expect not many "ABORT" events to be ignorable.
              A  special property of this command is that it works preemptive if given as program
              start argument. I.e. the first -abort_on setting among the start  arguments  is  in
              effect  already  when  the first operations of xorriso begin. Only "-abort_on" with
              dash "-" is recognized that way.

       -return_with severity exit_value
              Set the threshold and exit_value to be returned at program  end  if  no  abort  has
              happened.  This  is  to  allow xorriso to go on after problems but to get a failure
              indicating exit value from the program, nevertheless.  Useful is a value lower than
              the -abort_on threshold, down to "WARNING".
              exit_value  may be either 0 (indicating success to the starter of the program) or a
              number between 32 and 63. Some other exit_values are used by xorriso if it  decides
              to abort the program run:
              1=abort due to external signal
              2=no program arguments given
              3=creation of xorriso main object failed
              4=failure to start libburnia-project.org libraries
              5=program abort during argument processing
              6=program abort during dialog processing

       -report_about severity
              Set the threshold for events to be reported.
              Useful:  "SORRY", "WARNING", "HINT", "NOTE", "UPDATE", "DEBUG", "ALL"
              Regardless what is set by -report_about, messages get always reported if they reach
              the severity threshold of -abort_on .
              Event messages are sent to the info channel "I" which is usually stderr but may  be
              influenced  by  command  -pkt_output.   Info  messages which belong to no event get
              attributed severity "NOTE".
              A special property of this command is that the first  -report_about  setting  among
              the  start  arguments  is  in  effect  already when the first operations of xorriso
              begin. Only "-report_about" with dash "-" is recognized that way.

       -signal_handling mode
              Control the installation of a signal handler which shall react on external  signals
              (e.g.  from  program  "kill"  or  from  keys Ctrl+C) or on signals caused by severe
              program errors.
              Mode "on" is the default. It uses the signal handler of libburn which produces ugly
              messages but puts much effort in releasing optical drives before xorriso ends.
              Mode  "off"  as  first  -signal_handling among the start arguments prevents all own
              signal precautions of xorriso. Inherited signal handler settings stay as they are.
              It  works  like  "sig_dfl"  if  given  after  other  signal  handling  was  already
              established at program start.
              Mode  "sig_dfl"  uses  the  system  provided  default handling of signals, which is
              normally a sudden abort of the  program.  To  prevent  stuck  drives,  the  libburn
              handler is used during burning, blanking, and formatting on MMC drives.
              Mode  "sig_ign"  tries to ignore as many signal types as possible. This imposes the
              risk that xorriso refuses to end until externally kill -9 if  performed.   kill  -9
              then  imposes  the risk that the drive is left in unusable state and needs poweroff
              to be reset. So during burning, blanking, and formatting wait for  at  least  their
              normal run time before killing externally.
              A special property of this command is that the first -signal_handling setting among
              the start arguments is in effect already  when  the  first  operations  of  xorriso
              begin. Only "-signal_handling" with dash "-" is recognized that way.

       -error_behavior occasion behavior
              Control  the  program behavior at problem event occasions.  For now this applies to
              occasions "image_loading" which is given while an image tree is read from the input
              device,  and  to  "file_extraction"  which  is  given  with  osirrox  commands like
              -extract.
              With "image_loading" there are three behaviors available:
              "best_effort" goes on with reading after events with severity below FAILURE if  the
              threshold of command -abort_on allows this.
              "failure" aborts image tree reading on first event of at least SORRY.  It issues an
              own FAILURE event.  This is the default.
              "fatal" acts like "failure" but issues the own event as FATAL.
              With occasion "file_extraction" there are three behaviors:
              "keep" maintains incompletely extracted files on disk. This is the default.
              "delete" removes files which encountered errors during content extraction.
              "best_effort" starts a revovery attempt  by  means  of  -extract_cut  if  the  file
              content stems from the loaded ISO image and is not filtered.

       Dialog mode control:

       -dialog "on"|"off"|"single_line"
              Enable  or  disable to enter dialog mode after all program arguments are processed.
              In dialog mode input lines get prompted via readline or from stdin.
              If no -abort_on severity was set when dialog starts, then "NEVER" is set  to  avoid
              abort  in  most  cases  of wrong input or other problems. Before dialog begins, the
              default is "FAILURE" which e.g. aborts on unknown commands.
              Mode "on" supports input of newline characters  within  quotation  marks  and  line
              continuation  by  trailing  backslash  outside quotation marks.  Mode "single_line"
              does not.

       -page length width
              Describe terminal to the text pager. See also above, paragraph Result pager.
              If parameter length is nonzero then the user gets prompted  after  that  number  of
              terminal lines. Zero length disables paging.
              Parameter  width  is  the  number  of  characters  per terminal line. It is used to
              compute the number of terminal lines which get occupied by an output line.  A usual
              terminal width is 80.

       -use_readline "on"|"off"
              If "on" then use readline for dialog. Else use plain stdin.
              See also above, paragraph Dialog, Readline, Result pager.

       -reassure "on"|"tree"|"off"
              If "on" then ask the user for "y" or "n":
              before deleting or overwriting any file in the ISO image,
              before overwriting any disk file during restore operations,
              before rolling back pending image changes,
              before committing image changes to media,
              before changing the input drive,
              before blanking or formatting media,
              before ending the program.
              With  setting  "tree"  the  reassuring prompt will appear for an eventual directory
              only once and not for each file in its whole subtree.
              Setting "off" silently kills any kind of  image  file  object  and  performs  above
              irrevocable actions.
              To really produce user prompts, command -dialog needs to be set to "on".  Note that
              the prompt does not appear in situations where file removal is forbidden by command
              -overwrite.  -reassure  only  imposes an additional curb for removing existing file
              objects.
              Be aware that file objects  get  deleted  from  the  ISO  image  immediately  after
              confirmation.  They  are  gone  even  if  the  running command gets aborted and its
              desired effect gets revoked. In case of severe mess-up, consider to  use  -rollback
              to revoke the whole session.

       Drive and media related inquiry actions:

       -devices
              Show  list  of  available  MMC  drives with the addresses of their libburn standard
              device files.
              This is only possible when no ISO image changes are pending.   After  this  command
              was executed, there is no drive current and no image loaded.
              In  order  to  be  visible,  a  device has to offer rw-permissions with its libburn
              standard device file. Thus it might be only the superuser who is able  to  see  all
              drives.
              Drives which are occupied by other processes get not shown.

       -device_links
              Like  -devices,  but  presenting  the drives with addresses of symbolic links which
              point to the actual device files.
              Modern GNU/Linux systems may shuffle drive addresses from boot to boot.   The  udev
              daemon is supposed to create links which always point to the same drive, regardless
              of its system address.  The command -device_links shows the addresses of such links
              if  they  begin by "/dev/dvd" or "/dev/cd".  Precedence is: "dvdrw", "cdrw", "dvd",
              "cdrom", "cd".

       -toc
              Show media specific tables of content. This is the session history of  the  medium,
              not the ISO image directory tree.
              In case of overwriteable media holding a valid ISO image, it may happen that only a
              single session gets shown. But if the first session on the overwriteable media  was
              written by xorriso then a complete session history can be emulated.
              A  drive which is incapable of writing may show any media as CD-ROM or DVD-ROM with
              only one or two sessions on it. The last of these sessions is supposed  to  be  the
              most recent real session then.
              Some  read-only  drives  and  media show no usable session history at all.  Command
              -rom_toc_scan might help.
              If input device and output device are both acquired and not  the  same,  then  both
              tables-of-content get shown.

       -toc_of "in"|"out"|"all"[":short"]
              Like  command  -toc but explicitly choosing which drive's table-of-content to show.
              "in" shows -indev or -dev, "out" shows -outdev or -dev, "all"  shows  the  same  as
              -toc.
              If  ":short"  is  appended to the drive choosing word, then only a short summary of
              drive state and medium content is printed.
              As further difference to -toc, this command does not emit  FAILURE  events  if  the
              desired drive is not acquired.

       -mount_cmd drive entity id path
              Emit  an  appropriate command line for mounting the ISO session indicated by drive,
              entity and id.  The result will be different on GNU/Linux and on FreeBSD or NetBSD.
              drive can be "indev" or "outdev" to indicate already acquired drives, or it can  be
              the  path  of  a not yet acquired drive.  Prefix "stdio:" for non-MMC drives is not
              mandatory.
              For entity and id, see also command -load. They must be either "sbsector" with  the
              superblock sector address as id, or "track" with a track number as id, or "session"
              with a session number, or "volid" with a search  pattern  for  the  volume  id,  or
              "auto" with which any text as id mounts the first track of the last session.
              path will be used as mount point and must already exist as a directory on disk.
              The  command  gets  printed  to  the  result channel. See command -mount for direct
              execution of this command.

       -mount_opts option[:option...]
              Set options which influence -mount and -mount_cmd. Currently there is  only  option
              "exclusive"  which  is  default  and  its  counterpart  "shared". The latter causes
              xorriso not to give up the affected drive with command  -mount.   On  GNU/Linux  it
              adds  mount option "loop" which may enable mounting of several sessions of the same
              block device at the same time. One should not write to a mounted optical medium, of
              course. Take care to umount all sessions before ejecting.

       -session_string drive entity id format
              Print  to the result channel a text which gets composed according to format and the
              parameters of the addressed session.
              Formats "linux:"path or "freebsd:"path produce the output  of  -mount_cmd  for  the
              given operating systems.
              In  other texts xorriso will substitute the following parameter names.  An optional
              prefix "string:" will be removed.
              "%device%" will be substituted by the mountable device path of the drive address.
              "%sbsector%" will be substituted by the session start sector.
              "%track%", "%session%", "%volid%" will be  substituted  by  track  number,  session
              number, or volume id of the depicted session.

       -print_size
              Print  the  foreseeable  consumption  of 2048 byte blocks by next -commit. This can
              last a while as a -commit gets prepared and only in last moment is revoked by  this
              command.   The  result  depends  on several settings and also on the kind of output
              device.  If no -jidgo options are set and not command -as "mkisofs" was used,  then
              -padding (300 kB by default) is not counted as part of the image size.
              If  an  El  Torito  boot  image  file is already depicted, then command -print_size
              automatically executes -boot_image "any" "next".  This means that the properties of
              that boot image cannot be edited by subsequent commands.

       -tell_media_space
              Print  available  space  on  the output medium and the free space after subtracting
              already foreseeable consumption by next -commit.
              Note that the title of the prediction "After commit :" is misleading.  It is rather
              the  space that may still be filled in this session without making the next -commit
              fail from medium overflow.
              The free space after the next -commit might be smaller by several MB.  This depends
              on medium type, number of recorded sessions, and drive habits.

       -pvd_info
              Print  various  ID  strings and timestamps which can be found in loaded ISO images.
              Some of the IDs may be changed by commands like -volid or  -publisher.   For  these
              IDs  -pvd_info reports what would be written with the next -commit.  The timestamps
              get not automatically propagated from loaded image to newly written image. The ones
              for  new  images  may be set by command -volume_date.  See there for the meaning of
              the particular timestamps.

       -report_el_torito mode
              With mode plain print a report about the information found in the  El  Torito  boot
              catalog of the loaded ISO image.
              With  mode  help  print  a  text which explains the meaning of the lines put out by
              "plain".
              Mode cmd tries to print the xorriso commands which are  necessary  to  produce  the
              found  boot  equipment:  disk  identifiers, El Torito boot images, and System Area.
              Disk identifiers are strings which the booting operating system might use  to  find
              the ISO filesystem from where it comes. Currently known is the use of volume id and
              modification date.
              The intended use case is modification  of  the  filesystem  by  having  -indev  and
              -outdev  pointing to different images or drives.  The result might be insufficient,
              if the found equipment cannot be produced by  xorriso.  Various  SORRY  events  may
              arise  in  this  case,  but  it  is  not guaranteed that xorriso recognizes all its
              insufficiencies.
              Mode as_mkisofs tries to print the xorriso -as mkisofs options, which are necessary
              to  produce  the  found  equipment.   The  intended  use case is to use the mounted
              filesystem as input tree together with the printed options.

       -report_system_area mode
              With mode plain print a report about the information found in the  System  Area  of
              the loaded ISO image. The report consists of zero to many lines with a header text,
              a colon, and information text.
              With mode help print a text which explains the meaning of  the  lines  put  out  by
              "plain".  You  probably will have to look for more documentation which explains the
              technical details of the mentioned boot facilities.
              Modes cmd and as_mkisofs work like with command -report_el_torito. See above.
              With mode gpt_disk_guid print the GPT disk GUID of the loaded ISO in RFC 4122  text
              format  to  result  channel. It is not considered an error if no GPT is present. In
              this case nothing is printed to result channel.
              With mode gpt_crc_of:disk_path read up to 32 KiB from the disk file with  the  path
              given  after  the  colon.  Compute the GPT compliant CRC number and print it to the
              result channel. The number is shown like "0x690fd979".  The special  disk_path  "-"
              causes reading from standard input.
              With  mode  make_guid  print a pseudo-random GUID in RFC 4122 text format to result
              channel.

       Navigation in ISO image and disk filesystem:

       -cd iso_rr_path
              Change the current working directory in  the  ISO  image.   This  is  prepended  to
              iso_rr_paths which do not begin with '/'.
              It  is  possible to set the working directory to a path which does not exist yet in
              the ISO image. The necessary parent directories will be created when the first file
              object  is inserted into that virtual directory.  Use -mkdir if you want to enforce
              the existence of the directory already at first insertion.

       -cdx disk_path
              Change the current working directory in the local filesystem.  To be  prepended  to
              disk_paths which do not begin with '/'.

       -pwd
              Tell the current working directory in the ISO image.

       -pwdx
              Tell the current working directory in the local filesystem.

       -ls iso_rr_pattern [***]
              List files in the ISO image which match shell patterns (i.e. with wildcards '*' '?'
              '[a-z]').  If a pattern does not begin with '/' then it is compared with  addresses
              relative to -cd.
              Directories are listed by their content rather than as single file item.
              Pattern expansion may be disabled by command -iso_rr_pattern.

       -lsd iso_rr_pattern [***]
              Like  -ls  but  listing  directories  as themselves and not by their content.  This
              resembles shell command ls -d.

       -lsl iso_rr_pattern [***]
              Like -ls but also list some of the file attributes.  The  output  format  resembles
              shell command ls -ln.
              File type 'e' indicates the El Torito boot catalog.
              If the file has non-trivial ACL, then a '+' is appended to the permission info.  If
              the file is hidden, then 'I' for "iso_rr", 'J' for "joliet", 'A' for "hfsplus", 'H'
              for multiple hiding gets appended.  Together with ACL it is 'i', 'j', 'a', 'h'.

       -lsdl iso_rr_pattern [***]
              Like  -lsd  but also list some of the file attributes.  The output format resembles
              shell command ls -dln.

       -lsx disk_pattern [***]
              List files in the local filesystem which match shell patterns.  Patterns  which  do
              not begin with '/' are used relative to -cdx.
              Directories are listed by their content rather than as single file item.
              Pattern expansion may be disabled by command -disk_pattern.

       -lsdx disk_pattern [***]
              Like  -lsx  but  listing  directories as themselves and not by their content.  This
              resembles shell command ls -d.

       -lslx disk_pattern [***]
              Like -lsx but also listing some of the file attributes.   Output  format  resembles
              shell command ls -ln.

       -lsdlx disk_pattern [***]
              Like  -lsdx  but also listing some of the file attributes.  Output format resembles
              shell command ls -dln.

       -getfacl iso_rr_pattern [***]
              Print the access permissions of the given files in the ISO image using  the  format
              of  shell  command  getfacl.  If a file has no ACL then it gets fabricated from the
              -chmod settings. A file may have a real ACL if it was introduced into the ISO image
              while command -acl was set to "on".

       -getfacl_r iso_rr_pattern [***]
              Like  -gefacl  but  listing  recursively  the  whole file trees underneath eventual
              directories.

       -getfattr iso_rr_pattern [***]
              Print the xattr of the given files in the ISO image.  If a file has no  such  xattr
              then  noting is printed for it.  The choice of namespaces depends on the setting of
              command -xattr: "on" or "user" restricts it to namespace "user", "any"  only  omits
              namespace "isofs".

       -getfattr_r iso_rr_pattern [***]
              Like   -gefattr  but  listing  recursively  the  whole  file  trees  underneath  of
              directories.

       -du iso_rr_pattern [***]
              Recursively list size of directories and files in the ISO image which match one  of
              the patterns.  similar to shell command du -k.

       -dus iso_rr_pattern [***]
              List  size  of  directories  and  files  in  the  ISO  image which match one of the
              patterns.  Similar to shell command du -sk.

       -dux disk_pattern [***]
              Recursively list size of directories and files in the local filesystem which  match
              one of the patterns. Similar to shell command du -k.

       -dusx disk_pattern [***]
              List  size  of directories and files in the local filesystem which match one of the
              patterns.  Similar to shell command du -sk.

       -findx disk_path [-name pattern] [-type t] [-exec action [params]] --
              Like -find but operating on local filesystem and not on the  ISO  image.   This  is
              subject to the settings of -follow.
              -findx  accepts the same -type parameters as -find. Additionally it recognizes type
              "mountpoint" (or "m") which matches subdirectories  which  reside  on  a  different
              device than their parent. It never matches the disk_path given as start address for
              -findx.
              -findx accepts the -exec actions as  does  -find.  But  except  the  following  few
              actions it will always perform action "echo".
              in_iso  reports  the path if its counterpart exists in the ISO image.  For this the
              disk_path of  the  -findx  command  gets  replaced  by  the  iso_rr_path  given  as
              parameter.
              E.g.: -findx /home/thomas -exec in_iso /thomas_on_cd --
              not_in_iso reports the path if its counterpart does not exist in the ISO image. The
              report format is the same as with command -compare.
              add_missing iso_rr_path_start adds the counterpart if it does not yet exist in  the
              ISO image and marks it for "rm_merge" as non-removable.
              E.g.: -findx /home/thomas -exec add_missing /thomas_on_cd --
              is_full_in_iso  reports  if  the counterpart in the ISO image contains files. To be
              used with -type "m" to report mount points.
              empty_iso_dir deletes all files from the counterpart in the ISO image. To  be  used
              with -type "m" to truncate mount points.
              estimate_size  prints a lower and an upper estimation of the number of blocks which
              the found files together will occupy in the emerging  ISO  image.   This  does  not
              account  for  the  superblock, for the directories in the -findx path, or for image
              padding.
              list_extattr mode prints a script to the result channel, which  would  use  FreeBSD
              command setextattr to set the file's xattr name-value pairs of user namespace.  See
              -find for a description of parameter mode.
              E.g. -exec list_extattr e --

       -compare disk_path iso_rr_path
              Compare attributes and eventual data file content of  a  fileobject  in  the  local
              filesystem  with  a file object in the ISO image. The iso_rr_path may well point to
              an image file object which is not yet committed, i.e. of  which  the  data  content
              still  resides  in  the  local filesystem. Such data content is prone to externally
              caused changes.
              If iso_rr_path is empty then disk_path is used as path in the ISO image too.
              Differing attributes are reported in detail, differing content is summarized.  Both
              to the result channel. In case of no differences no result lines are emitted.

       -compare_r disk_path iso_rr_path
              Like  -compare  but working recursively. I.e. all file objects below both addresses
              get compared whether they have counterparts below the  other  address  and  whether
              both counterparts match.

       -compare_l disk_prefix iso_rr_prefix disk_path [***]
              Perform  -compare_r  with  each  of  the  disk_path parameters. iso_rr_path will be
              composed from disk_path by replacing disk_prefix by iso_rr_prefix.

       -show_stream iso_rr_path [***]
              Display the content stream chain of data files in the ISO image. The chain consists
              of  the  iso_rr_name  and  one or more streams, separated by " < " marks.  A stream
              description consists of one or more texts, separated by ":" characters.  The  first
              text  tells  the  stream type, the following ones, if ever, describe its individual
              properties.  Frequently used types are:
               disk:'disk_path'  for local filesystem objects.
               image:'iso_rr_path'  for ISO image file objects.
               cout:'disk_path offset count'  for -cut_out files.
               extf:'filter_name' for external filters.
              Example:
               '/abc/xyz.gz' < extf:'gzip' < disk:'/home/me/x'

       -show_stream_r iso_rr_path [***]
              Like -show_stream but working recursively.

       Evaluation of readability and recovery:

       It is not uncommon that optical media produce read errors. The reasons may be various  and
       get  obscured by error correction which is performed by the drives and based on extra data
       on the media. If a drive returns data then one can quite trust that they are valid. But at
       some  degree  of  read  problems  the  correction  will  fail and the drive is supposed to
       indicate error.
       xorriso can scan a medium for readable data blocks, classify them according to their  read
       speed,  save them to a file, and keep track of successfully saved blocks for further tries
       on the same medium.
       By command -md5 checksums may get recorded with  data  files  and  whole  sessions.  These
       checksums are reachable only via indev and a loaded image.  They work independently of the
       media type and can detect transmission errors.

       -check_media [option [option ...]] --
              Try to read data blocks from the indev drive, optionally copy them to a disk  file,
              and  finally  report  about the encountered quality. Several options may be used to
              modify the default behavior.
              The parameters given with this command override the default settings which may have
              been  changed  by  command  -check_media_defaults.  See  there for a description of
              available options.
              The result list tells intervals of 2 KiB  blocks  with  start  address,  number  of
              blocks  and  quality.  Qualities  which  begin  with  "+"  are supposed to be valid
              readable data. Qualities with "-" are unreadable or corrupted data.  "0"  indicates
              qualities  which  are  not  covered by the check run or are regularly allowed to be
              unreadable (e.g. gaps between tracks).
              Alternatively it is possible to report damaged files rather than blocks.
              If -md5 is "on" then the default mode what=tracks looks out for  libisofs  checksum
              tags  for  the ISO session data and checks them against the checksums computed from
              the data stream.

       -check_media_defaults [option [option ...]] --
              Preset  options  for  runs  of  -check_media,  -extract_cut  and  best_effort  file
              extraction.  Options  given  with  -check_media  will  override the preset options.
              -extract_cut will override some options automatically.
              An option consists of a keyword, a "=" character, and a value. Options may override
              each other. So their sequence matters.
              The default setting at program start is:
              use=indev what=tracks min_lba=-1 max_lba=-1 retry=default
              time_limit=28800 item_limit=100000 data_to='' event=ALL
              abort_file=/var/opt/xorriso/do_abort_check_media
              sector_map='' map_with_volid=off patch_lba0=off report=blocks
              bad_limit=invalid slow_limit=1.0 chunk_size=0s async_chunks=0
              Option "reset=now" restores these startup defaults.
              Non-default options are:
              report="files" lists the files which use damaged blocks (not with use=outdev).  The
              format is like with find -exec report_damage.  Note that  a  MD5  session  mismatch
              marks  all  files  of  the  session  as  damaged.  If finer distinction is desired,
              perform -md5 off before -check_media.
              report="blocks_files" first lists damaged blocks and then affected files.
              use="outdev" reads from the output drive instead of the input  drive.  This  avoids
              loading the ISO image tree from media.
              use="sector_map"  does  not  read  any  media  but  loads  the file given by option
              sector_map= and processes this virtual outcome.
              what="disc" scans the payload range of a medium without respecting track gaps.
              what="image" similar to "disc", but restricts scanning to the range of the ISO 9660
              image, if present.
              min_lba=limit omits all blocks with addresses lower than limit.
              max_lba=limit switches to what=disc and omits all blocks above limit.
              chunk_size=size  sets  the  number  of  bytes  to  be  read  in  one low-level read
              operation.  This gets rounded down to full blocks of 2048 bytes. 0 means  automatic
              size.
              retry="on"  forces  read  retries  with minimal senseful chunk size when the normal
              read chunk produces a read error. This size is 1s with CD and stdio files, 16s with
              DVD  (1  ECC  Block),  and  32s  with BD (1 Cluster).  By default, retries are only
              enabled with CD media. "retry=off" forbits retries for all media types.
              abort_file=disk_path gives the path of the file which may abort a scan  run.  Abort
              happens  if  the  file exists and its mtime is not older than the start time of the
              run. Use shell command "touch" to trigger this.  Other than an aborted program run,
              this will report the tested and untested blocks and go on with running xorriso.
              time_limit=seconds  gives  the  number  of  seconds  after  which the scan shall be
              aborted. This is useful for unattended scanning of media which  may  else  overwork
              the  drive in its effort to squeeze out some readable blocks.  Abort may be delayed
              by the drive gnawing on the last single read operation.  Value -1  means  unlimited
              time.
              item_limit=number  gives  the  number  of  report  list items after which to abort.
              Value -1 means unlimited item number.
              data_to=disk_path copies the valid blocks to the given file.
              event=severity sets the given severity for a problem event which shall be issued at
              the  end  of a check run if data blocks were unreadable or failed to match recorded
              MD5 checksums. Severity "ALL" disables this event.
              sector_map=disk_path tries to read the file given by disk_path as sector bitmap and
              to  store  such  a map file after the scan run.  The bitmap tells which blocks have
              been read successfully in previous runs.  It is the persistent memory  for  several
              scans  on  the  same  medium,  even  with  intermediate  eject, in order to collect
              readable blocks whenever the drive is lucky enough to produce them. The stored file
              contains  a  human readable TOC of tracks and their start block addresses, followed
              by binary bitmap data.
              By default, untested blocks are not considered bad,  but  rather  as  intentionally
              unread. If you expect time_limit= or item_limit= to abort the run, then consider to
              use bad_limit="untested".
              map_with_volid="on" examines tracks whether they are ISO images  and  prints  their
              volume IDs into the human readable TOC of sector_map=.
              patch_lba0="on"  transfers  within the data_to= file a copy of the currently loaded
              session head to the start of that file and patches it to be valid at that position.
              This makes the loaded session the last valid session of the image file when it gets
              mounted or loaded as stdio: drive. New sessions will be appended  after  this  last
              session and will overwrite any sessions which have followed it.
              patch_lba0="force"  performs  patch_lba0="on"  even  if  xorriso  believes that the
              copied data are not valid.
              patch_lba0= may also bear a number. If it is 32 or higher  it  is  taken  as  start
              address  of  the  session to be copied. In this case it is not necessary to have an
              -indev and a loaded image. ":force" may be appended after the number.
              bad_limit=threshold sets the highest quality which shall be considered  as  damage.
              Choose   one  of  "good",  "md5_match",  "slow",  "partial",  "valid",  "untested",
              "md5_mismatch", "invalid", "tao_end", "off_track", "unreadable".
              "valid" and "invalid" are qualities imported from a sector_map file.  "tao_end" and
              "off_track"  are  intentionally  not  readable,  but not bad either.  "partial" are
              blocks retrieved from a partially readable chunk. They are supposed to  be  ok  but
              stem from a suspicious neighborhood.
              "md5_match"  and "md5_mismatch" regions overlap with regions of other quality.  The
              former is a strong confirmation for quality, the latter only tells that one or more
              blocks of the region must be wrong.
              slow_limit=threshold  sets  the  time  threshold  for  a  single  read  chunk to be
              considered slow. This may be a fractional number like 0.1 or 1.5.
              async_chunks=number enables asynchronous MD5 processing if number is 2  or  larger.
              In  this case the given number of read chunks is allocated as fifo buffer.  On very
              fast MMC drives try: chunk_size=64s async_chunks=16.

       -check_md5 severity iso_rr_path [***]
              Compare the data content of the given files in the loaded image with their recorded
              MD5  checksums,  if  there  are  any. In case of any mismatch an event of the given
              severity is issued. It may then be handled  by  appropriate  settings  of  commands
              -abort_on  or -return_with which both can cause non-zero exit values of the program
              run. Severity ALL suppresses that event.
              This command reports match and mismatch  of  data  files  to  the  result  channel.
              Non-data  files  cause  NOTE  events.  There  will  also be UPDATE events from data
              reading.
              If no iso_rr_path is given then the whole loaded session is compared with  its  MD5
              sum.  Be  aware  that this covers only one session and not the whole image if there
              are older sessions.

       -check_md5_r severity iso_rr_path [***]
              Like -check_md5 but checking all data  files  underneath  the  given  paths.   Only
              mismatching data files will be reported.

       osirrox ISO-to-disk restore commands:

       Normally  xorriso only writes to disk files which were given as stdio: pseudo-drives or as
       log files.  But its alter ego osirrox is able to extract file objects from ISO images  and
       to create, overwrite, or delete file objects on disk.
       Disk  file  exclusions  by  -not_mgt,  -not_leaf,  -not_paths apply.  If disk file objects
       already exist then the settings of -overwrite and -reassure  apply.  But  -overwrite  "on"
       only triggers the behavior of -overwrite "nondir". I.e. directories cannot be deleted.
       Access  permissions  of  files  in the ISO image do not restrict restoring.  The directory
       permissions on disk have to allow rwx.

       -osirrox setting[:option:...]
              Setting "off" disables disk filesystem manipulations. This is  the  default  unless
              the program was started with leafname "osirrox". Elsewise the capability to restore
              files can be enabled explicitly by -osirrox "on".  It can be  irrevocably  disabled
              by -osirrox "banned".
              The  setting  "blocked"  is  like  "off".  But  it  can  only be revoked by setting
              "unblock", which elsewise is like "on". This can be used to  curb  command  scripts
              which might use "on" undesiredly.
              To  enable  restoring  of special files by "device_files" is potentially dangerous.
              The meaning of the number st_rdev (see man 2 stat) depends much  on  the  operating
              system.  Best  is  to  restore device files only to the same system from where they
              were copied. If not enabled, device files in  the  ISO  image  are  ignored  during
              restore operations.
              Due  to  a bug of previous versions, device files from previous sessions might have
              been altered to major=0, minor=1. So this combination does not get restored.
              Option "concat_split_on" is default. It enables restoring of split file directories
              as  data  files  if  the  directory contains a complete collection of -cut_out part
              files. With option "concat_split_off" such directories are handled like  any  other
              ISO image directory.
              Option   "auto_chmod_off"  is  default.  If  "auto_chmod_on"  is  set  then  access
              restrictions for disk directories get circumvented if those directories  are  owned
              by  the  effective  user who runs xorriso. This happens by temporarily granting rwx
              permission to the owner.
              Option "sort_lba_on" may improve read  performance  with  optical  drives.  It  can
              restore large numbers of hard links without exhausting -temp_mem_limit. It does not
              preserve directory mtime and it needs -osirrox option  auto_chmod_on  in  order  to
              extract directories which offer no write permission. Default is "sort_lba_off".
              Option  "o_excl_on"  is  the  default  unless the program was started with leafname
              "osirrox". On GNU/Linux it tries to avoid using drives which are mounted or in  use
              by other libburn programs.  Option "o_excl_off" on GNU/Linux enables access to such
              drives. Drives which get acquired while "o_excl_off" will refuse  to  get  blanked,
              formatted, written, or ejected. But be aware that even harmless inquiries can spoil
              ongoing burns of CD-R[W] and DVD-R[W].
              Option "strict_acl_off" is  default.  It  tolerates  on  FreeBSD  the  presence  of
              directory  "default"  ACLs  in  the ISO image. With "strict_acl_on" these GNU/Linux
              ACLs cause on FreeBSD a FAILURE event during restore with -acl "on".

       -extract iso_rr_path disk_path
              Copy the  file  objects  at  and  underneath  iso_rr_path  to  their  corresponding
              addresses at and underneath disk_path.  This is the inverse of -map or -update_r.
              If  iso_rr_path  is  a  directory  and disk_path is an existing directory then both
              trees will be merged. Directory attributes get extracted only if the disk directory
              is newly created by the copy operation.  Disk files get removed only if they are to
              be replaced by file objects from the ISO image.
              As many attributes as possible are copied together with restored file objects.

       -extract_single iso_rr_path disk_path
              Like -extract, but if iso_rr_path is  a  directory  then  its  sub  tree  gets  not
              restored.

       -extract_l iso_rr_prefix disk_prefix iso_rr_path [***]
              Perform  -extract  with  each  of  the  iso_rr_path  parameters.  disk_path will be
              composed from iso_rr_path by replacing iso_rr_prefix by disk_prefix.

       -extract_cut iso_rr_path byte_offset byte_count disk_path
              Copy a byte interval from a data file out of an ISO image into a newly created disk
              file.   The main purpose for this is to offer a way of handling large files if they
              are not supported by mount -t iso9660 or if the target disk filesystem cannot store
              large files.
              If  the data bytes of iso_rr_path are stored in the loaded ISO image, and no filter
              is applied, and  byte_offset  is  a  multiple  of  2048,  then  a  special  run  of
              -check_media  is  performed.  It  may  be  quicker and more rugged than the general
              reading method.

       -cpx iso_rr_path [***] disk_path
              Copy single leaf file objects from the ISO image to the address given by disk_path.
              If  more  then  one  iso_rr_path  is  given  then  disk_path must be a directory or
              non-existent. In the latter case it  gets  created  and  the  extracted  files  get
              installed in it with the same leafnames.
              Missing directory components in disk_path will get created, if possible.
              Directories  are  allowed  as  iso_rr_path only with -osirrox "concat_split_on" and
              only if they actually represent a complete collection of -cut_out split file parts.

       -cpax iso_rr_path [***] disk_path
              Like -cpx but restoring mtime, atime as in ISO image and trying  to  set  ownership
              and group as in ISO image.

       -cp_rx iso_rr_path [***] disk_path
              Like -cpx but also extracting whole directory trees from the ISO image.
              The  resulting disk paths are determined as with shell command cp -r : If disk_path
              is an existing directory then the trees will be inserted or merged underneath  this
              directory  and  will  keep their leaf names. The ISO directory "/" has no leaf name
              and thus gets mapped directly to disk_path.

       -cp_rax iso_rr_path [***] disk_path
              Like -cp_rx but restoring mtime, atime as in ISO image and trying to set  ownership
              and group as in ISO image.

       -paste_in iso_rr_path disk_path byte_offset byte_count
              Read the content of a ISO data file and write it into a data file on disk beginning
              at the byte_offset. Write at most byte_count bytes.  This is the inverse of command
              -cut_out.

       -concat mode [target | lim prog [args [...]] lim] iso_rr_path [***]
              Copy  the  data content of one or more data files of the ISO image into a disk file
              object, into a file descriptor, or start a program  and  copy  the  data  into  its
              standard  input.   The  latter is subject to the security restrictions for external
              filters.
              Modes overwrite and append write into the target  which  is  given  by  the  second
              parameter.  This may be the path to a disk file object, or "-" which means standard
              output, or a text of  the  form  /dev/fd/number,  where  number  is  an  open  file
              descriptor  (e.g.  standard  error  is  /dev/fd/2).  An existing target file is not
              removed before writing begins. If it is not able to take content  data,  then  this
              command  fails.   Mode  overwrite  truncates  regular  data  files to 0 size before
              writing into them.  Example:
               -concat append /home/me/accumulated_text /my/iso/text --

              Mode pipe expects as second parameter a delimiter word which shall mark the end  of
              the  program  argument list. The third argument is the disk_path to the program. It
              must contain at least one '/'. $PATH is not applied.  Further parameters up to  the
              announced delimiter word are used as arguments with the program start. Example:
               -iso_rr_pattern on \
               -concat pipe + /usr/bin/wc + "/my/iso/files*" --

              The  further  parameters  in  all  modes are the iso_rr_paths of data files.  Their
              content gets concatenated in the copy.

       -mount drive entity id path
              Produce the same line as -mount_cmd and then execute it  as  external  program  run
              after giving up the depicted drive. See also -mount_opts.  This demands -osirrox to
              be enabled and normally will succeed only for the superuser. For safety reasons the
              mount program is only executed if it is reachable as /bin/mount or /sbin/mount.

       Command compatibility emulations:

       Writing  of  ISO  9660  on  CD  is traditionally done by program mkisofs as ISO 9660 image
       producer and cdrecord as burn program.  xorriso does not strive  for  their  comprehensive
       emulation.   Nevertheless  it  is ready to perform some of its core tasks under control of
       commands which in said programs trigger comparable actions.

       -as personality option [options] --
              Perform the variable length option list as sparse emulation of the program depicted
              by the personality word.

              Personality "mkisofs" accepts the options listed with:
                -as mkisofs -help --
              Among  them: -R (always on), -r, -J, -o, -M, -C, -dir-mode, -file-mode, -path-list,
              -m, -exclude-list, -f, -print-size, -pad, -no-pad, -V, -v, -version, -graft-points,
              -z,  -no-emul-boot,  -b, -c, -boot-info-table, -boot-load-size, -input-charset, -G,
              -output-charset, -U, -hide, -hide-joliet, -hide-list, -hide-joliet-list, file paths
              and  pathspecs.   A  lot  of  options  are not supported and lead to failure of the
              mkisofs emulation. Some are ignored, but better do not rely on this tolerance.
              The supported options are  documented  in  detail  in  xorrisofs.info  and  in  man
              xorrisofs.  The  description  here is focused on the effect of mkisofs emulation in
              the context of a xorriso run.
              Other than with the "cdrecord" personality there is no automatic -commit at the end
              of  a  "mkisofs"  option  list.  Verbosity  settings  -v (= "UPDATE") and -quiet (=
              "SORRY") persist. The output  file  persists  until  things  happen  like  -commit,
              -rollback, -dev, or end of xorriso.
              Options  which affect all file objects in the ISO image, like -r or -dir-mode, will
              be applied only to files which are present in the ISO image when  the  command  -as
              ends. If you use several -as mkisofs commands in the same run, then consider to put
              such options into the last -as command.
              If files are added  to  the  image,  then  -pacifier  gets  set  to  "mkisofs"  and
              -stdio_sync is defaulted to "off" if no such setting was made yet.
              -graft-points  is  equivalent to -pathspecs on. Note that pathspecs without "=" are
              interpreted differently than with xorriso command  -add.   Directories  get  merged
              with the root directory of the ISO image, other filetypes get mapped into that root
              directory.
              If pathspecs are given and if no output  file  was  chosen  before  or  during  the
              "mkisofs" option list, then standard output (-outdev "-") will get into effect.  If
              -o points to a regular file, then it will be truncated  to  0  bytes  when  finally
              writing  begins.  This truncation does not happen if the drive is chosen by xorriso
              commands before -as mkisofs or after its list delimiter. Directories  and  symbolic
              links are no valid -o targets.
              Writing  to  stdout is possible only if -as "mkisofs" was among the start arguments
              or if other start arguments pointed the output drive to standard output.
              -print-size inhibits automatic image production at program end. This ban is  lifted
              only if the pending image changes get discarded.
              Padding is counted as part of the ISO image if not option --emul-toc is given.
              If  no -iso-level is given, then level 1 is chosen when the first file or directory
              is added to the image. At the same occasion directory names get allowed to  violate
              the standard by -compliance option allow_dir_id_ext.  This may be avoided by option
              -disallow_dir_id_ext.
              Option -root is supported. Option -old-root  is  implemented  by  xorriso  commands
              -mkdir, -cp_clone, -find update_merge, and -find rm_merge.  -root and -old-root set
              command -disk_dev_ino to "ino_only" and -md5 to "on",  by  default.   -disk_dev_ino
              can be set to "off" by --old-root-no-ino or to "on" by --old-root-devno .  -md5 can
              be set to "off" by --old-root-no-md5 .
              Not original mkisofs options are --quoted_path_list , --hardlinks , --acl , --xattr
              ,  --md5  ,  --stdio_sync .  They work like the xorriso commands with the same name
              and hardcoded parameter "on", e.g. -acl "on".  Explicit parameters are expected  by
              --stdio_sync and --scdbackup_tag.
              The  capability  to  preserve  multi-session  history  on  overwriteable media gets
              disabled by default. It can be enabled by using --emul-toc with the first  session.
              See -compliance no_emul_toc.
              --sort-weight  gets  as parameters a number and an iso_rr_path.  The number becomes
              the LBA sorting weight  of  regular  file  iso_rr_path  or  of  all  regular  files
              underneath directory iso_rr_path.  (See -find -exec sort_weight).
              Adopted  from  grub-mkisofs  are  --protective-msdos-label  (see  -boot_image  grub
              partition_table=on)  and  --modification-date=YYYYMMDDhhmmsscc  (see   -volume_date
              uuid).  For  EFI bootable GRUB boot images use --efi-boot.  It performs -boot_image
              grub efi_path= surrounded by two -boot_image "any" "next".  Alternative  option  -e
              from  Fedora  genisoimage  sets  bin_path  and platform_id for EFI, but performs no
              "next".
              For MBR bootable ISOLINUX images there is -isohybrid-mbr FILE, where FILE is one of
              the  Syslinux  files  mbr/isohdp[fp]x*.bin  .  Use  this instead of -G to apply the
              effect of -boot_image isolinux partition_table=on.
              --boot-catalog-hide is -boot_image any cat_hidden=on.
              -mips-boot is the same as -boot_image any mips_path= .
              -mipsel-boot leads to mipsel_path= .
              -partition_offset number is -boot_image any partition_offset=number.
              Command -append_partition is supported.
              -untranslated_name_len number is -compliance untranslated_name_len=number.
              --old-empty is -compliance old_empty.
              The options of genisoimage Jigdo Template Extraction are recognized  and  performed
              via  xorriso  command  -jigdo.  See the "Alias:" names there for the meaning of the
              genisoimage options.

              Personalities "xorrisofs", "genisoimage", and "genisofs" are aliases for "mkisofs".
              If xorriso is started with one of the leafnames "xorrisofs", "genisofs", "mkisofs",
              or  "genisoimage",  then it performs -read_mkisofsrc and prepends -as "genisofs" to
              the program arguments.  I.e. all arguments will be interpreted mkisofs style  until
              "--" is encountered.  From then on, arguments are interpreted as xorriso commands.
              --no_rc  as  first  argument  of  such  a  program start prevents interpretation of
              startup files. See section FILES below.

              Personality "cdrecord" accepts the options listed with:
                -as cdrecord -help --
              Among them: -v,  dev=,  speed=,  blank=,  fs=,  -eject,  -atip,  padsize=,  tsize=,
              -isosize,  -multi,  -msinfo,  --grow_overwriteable_iso, write_start_address=, track
              source file path or "-" for standard input as track source.
              It ignores most other options of  cdrecord  and  cdrskin  but  refuses  on  -audio,
              -scanbus, and on blanking modes unknown to xorriso.
              The  scope  is  only  a  single  data  track  per  session  to be written to blank,
              overwriteable, or appendable media. The medium gets closed if closing is applicable
              and not option -multi is present.
              If  an  input  drive was acquired, then it is given up.  This is only allowed if no
              image changes are pending.
              dev= must be given as xorriso device address. Addresses like 0,0,0 or ATA:1,1,0 are
              not supported.
              If  a  track  source  is given, then an automatic -commit happens at the end of the
              "cdrecord" option list.
              --grow_overwriteable_iso enables emulation of multi-session on overwriteable media.
              To enable emulation of a TOC, the first session needs -C 0,32 with -as mkisofs (but
              no -M) and --grow_overwriteable_iso write_start_address=32s with -as cdrecord.
              A much more elaborate libburn based cdrecord emulator is the program cdrskin.
              Personalites "xorrecord", "wodim", and "cdrskin" are aliases for "cdrecord".
              If xorriso is started with one of the leafnames "xorrecord", "cdrskin", "cdrecord",
              or  "wodim", then it automatically prepends -as "cdrskin" to the program arguments.
              I.e. all arguments will be interpreted cdrecord style until  "--"  is  encountered.
              From then on, arguments are interpreted as xorriso commands.
              --no_rc  as  first  argument  of  such  a  program start prevents interpretation of
              xorriso startup files.  See section FILES below.

       -read_mkisofsrc
              Try one by one to open for reading:
               ./.mkisofsrc , $MKISOFSRC , $HOME/.mkisofsrc , $(dirname $0)/.mkisofsrc
              On success interpret the file content as of man mkisofs CONFIGURATION, and end this
              command. Do not try further files.  The last address is used only if start argument
              0 has a non-trivial dirname.
              The  reader   currently   interprets   the   following   NAME=VALUE   pairs:   APPI
              (-application_id)  ,  PUBL  (-publisher) , SYSI (-system_id) , VOLI (-volid) , VOLS
              (-volset_id)
              Any other lines will be silently ignored.

       -pacifier behavior_code
              Control behavior of  UPDATE  pacifiers  during  write  operations.   The  following
              behavior codes are defined:
              "xorriso" is the default format:
              Writing: sector XXXXX of YYYYYY  [fifo active, nn% fill]
              "cdrecord" looks like:
              X of Y MB written (fifo nn%) [buf mmm%]
              "mkisofs"
              nn% done, estimate finish Tue Jul 15 20:13:28 2008
              The frequency of the messages can be adjusted by
              "interval=number"
              where  number  gives the seconds between two messages. Permissible settings are 0.1
              to 60.0.

       -scdbackup_tag list_path record_name
              Set the parameter "name" for a scdbackup checksum record.  It will be  appended  in
              an  scdbackup  checksum  tag  to the -md5 session tag if the image starts at LBA 0.
              This is the case if it gets written as first session onto a sequential  medium,  or
              piped into a program, named pipe or character device.
              If  list_path  is  not empty then the record will also be appended to the data file
              given by this path.
              Program scdbackup_verify will recognize and verify tag and file record.
              An empty record_name disables this feature.

       Scripting, dialog and program control features:

       -no_rc
              Only  if  used  as  first  program  argument  this  command  prevents  reading  and
              interpretation of startup files. See section FILES below.

       -options_from_file fileaddress
              Read  quoted  input from fileaddress and execute it like dialog lines.  Empty lines
              and lines which begin by # are ignored. Normally one line should hold  one  xorriso
              command  and  all  its  parameters.   Nevertheless  lines  may be concatenated by a
              trailing backslash.
              See also section "Command processing", paragraph "Quoted input".

       -help
              Print helptext.

       -version
              Print program name and version, component versions, license.

       -list_extras code
              Tell whether certain extra features were enabled at compile time.  Code "all" lists
              all  features  and  a  headline.   Other codes pick a single feature.  Code "codes"
              lists them. They share names with related commands (see also there):
              "acl" tells whether xorriso has an adapter for local filesystems ACLs.
              "xattr" tells whether xorriso has an adapter for local filesystems EA.
              "jigdo" tells whether production of Jigdo files is possible.
              "zisofs" tells whether zisofs and built-in gzip filters are enabled.
              "external_filter" tells whether external filter processes are allowed  and  whether
              they are allowed if real user id and effective user id differ.
              "dvd_obs" tells whether 64 kB output to DVD media is default.
              "use_readline" tells whether readline may be enabled in dialog mode.

       -history textline
              Copy textline into libreadline history.

       -status mode|filter
              Print the current settings of xorriso.  Modes:
                short... print only important or altered settings
                long ... print all settings including defaults
                long_history  like long plus history lines
              Filters  begin  with  '-'  and  are  compared literally against the output lines of
              -status:long_history. A line is put out only if its start matches the filter  text.
              No wildcards.

       -status_history_max number
              Set maximum number of history lines to be reported with -status "long_history".

       -list_delimiter word
              Set  the  list  delimiter  to be used instead of "--".  It has to be a single word,
              must not be empty, not longer than 80 characters, and must  not  contain  quotation
              marks.
              For brevity the list delimiter is referred as "--" throughout this text.

       -sh_style_result "on"|"off"
              Make  the  result  output of some filesystem inspection commands look more like the
              output of equivalent shell commands. The most important effect is  to  prevent  the
              wrapping of file addresses into quotation marks with commands
                -pwd -pwdx -ls -lsd -lsl -lsdl -lsx -lsdx -lslx -lsdlx
                -du -dus -dux -dusx -findx -find
              This  will  make  ambiguous  the representation of file names which contain newline
              characters. On the other hand it should  facilitate  integration  of  xorriso  into
              shell scripts which already use the corresponding shell commands.

       -backslash_codes "on"|"off"|mode[:mode]
              Enable  or  disable  the  interpretation  of  symbolic  representations  of special
              characters with quoted input, or with  program  arguments,  or  with  program  text
              output. If enabled the following translations apply:
               \a=bell(007) \b=backspace(010) \e=Escape(033) \f=formfeed(014)
               \n=linefeed(012) \r=carriage_return(015) \t=tab(011)
               \v=vtab(013) \\=backslash(134) \[0-7][0-7][0-7]=octal_code
               \x[0-9a-f][0-9a-f]=hex_code \cC=control-C
              Translations can occur with quoted input in 3 modes:
               "in_double_quotes" translates only inside " quotation.
               "in_quotes" translates inside " and ' quotation.
               "with_quoted_input" translates inside and outside quotes.
              With the start program arguments there is mode:
               "with_program_arguments" translates program arguments.
              Mode  "encode_output"  encodes output characters. It combines "encode_results" with
              "encode_infos". Inside single or double quotation marks encoding applies  to  8-bit
              characters  octal 001 to 037 , 177 to 377 and to backslash(134).  Outside quotation
              marks  some  harmless  ASCII  control   characters   stay   unencoded:   bell(007),
              backspace(010), tab(011), linefeed(012), formfeed(014), carriage_return(015).
              Mode   "off"   is   default   and   disables   any   translation.    Mode  "on"  is
              "with_quoted_input:with_program_arguments:encode_output".

       -temp_mem_limit number["k"|"m"]
              Set the maximum size of temporary memory to be used for image dependent  buffering.
              Currently this applies to pattern expansion, LBA sorting, restoring of hard links.
              Default is 16m = 16 MiB, minimum 64k = 64 kiB, maximum 1024m = 1 GiB.

       -print  text
              Print a text line to the result channel which is by default stdout.

       -print_info  text
              Print a text line to the info channel which is by default stderr.

       -print_mark  text
              Print  a text line to the mark channel which is by default directed to both, result
              and info channel. An empty text will cause no output at all.

       -prompt text
              Show text at beginning of output line and wait for the user to hit the Enter key or
              to send a line via stdin.

       -sleep seconds
              Wait  for  the  given number of seconds before performing the next command.  Expect
              coarse granularity no better than 1/100 seconds.

       -errfile_log mode path|channel
              If problem events are related to  input  files  from  the  filesystem,  then  their
              disk_paths can be logged to a file or to output channels R or I.
              Mode  can  either be "plain" or "marked". The latter causes marker lines which give
              the time of log start, burn session start, burn session end,  log  end  or  program
              end. In mode "plain", only the file paths are logged.
              If  path  is "-" or "-R" then the log is directed to the result channel.  Path "-I"
              directs it to the info message channel. Any text that does not begin  with  "-"  is
              used as path for a file to append the log lines.
              Problematic  files  can  be recorded multiple times during one program run.  If the
              program run aborts then the list might not be complete  because  some  input  files
              might not have been processed at all.
              The errfile paths are transported as messages of very low severity "ERRFILE".  This
              transport becomes visible with -report_about "ALL".

       -session_log path
              If path is not empty it gives the address of a plain text file where a  log  record
              gets  appended  after each session. This log can be used to determine the start_lba
              of a session for mount options -o sbsector= (on GNU/Linux) or -s (on FreeBSD)  from
              date or volume ID.
              Record format is: timestamp start_lba size volume-id
              The first three items are single words, the rest of the line is the volume ID.

       -scsi_log "on"|"off"
              Mode "on" enables very verbous logging of SCSI commands and drive replies.  Logging
              messages get printed to stderr, not to any of the xorriso output channels.
              A special property of this command is that the first -scsi_log  setting  among  the
              start  arguments  is  in effect already when the first operations of xorriso begin.
              Only "-scsi_log" with dash "-" is recognized that way.

       -end
              End program after writing pending changes.

       -rollback_end
              Discard pending changes. End program immediately.

       # any text
              Only in dialog or file execution mode, and only as first non-whitespace in line: Do
              not execute the line but store it in readline history.

       Support for frontend programs via stdin and stdout:

       -pkt_output "on"|"off"
              Consolidate text output on stdout and classify each line by a channel indicator:
               'R:' for result lines,
               'I:' for notes and error messages,
               'M:' for -mark texts.
              Next  is  a  decimal  number of which only bit 0 has a meaning for now.  0 means no
              newline at end of payload, 1 means that the newline character at  the  end  of  the
              output  line  belongs  to  the payload. After another colon and a blank follows the
              payload text.
              Example:
               I:1: enter option and parameters :

       -logfile channel fileaddress
              Copy output of a channel to the given file. Channel may be  one  of:  "."  for  all
              channels, "I" for info messages, "R" for result lines, "M" for -mark texts.

       -mark text
              If  text is not empty it will get put out on "M" channel each time xorriso is ready
              for the next dialog line or before xorriso performs a command that was  entered  to
              the pager prompt.

       -msg_op opcode parameter_text
              This command shall facilitate extraction of particular information from the message
              output  of  other   commands.   It   gives   access   to   the   C   API   function
              Xorriso_parse_line()  and  to  the  message  sieve  that  is provided by the C API.
              Please refer to  their  descriptions  in  file  xorriso.h.   Further  it  helps  to
              interpret the severity codes of info messages.
              Intended users are frontend programs which operate xorriso in dialog mode.
              The result output of this command is not caught by the message sieve.
              The following opcodes are defined:
              start_sieve
              Install  the  message  sieve  as  of Xorriso_sieve_big() and start watching program
              messages. The parameter_text has no meaning.
              show_sieve
              Show a list of filter rule names. The parameter_text  has  no  meaning.   The  list
              begins  by  a  line  with  the return value of Xorriso_sieve_get_result() with flag
              bit3. If this value is larger than 0, then the next line tells the number of names.
              The following lines show one name each.
              read_sieve
              Use  the  parameter_text  as  name  of  a filter rule and inquire its next recorded
              result.  See Xorriso_sieve_big() for a list of names and reply strings.
              The recorded strings are put out on result channel. They  get  wrapped  into  lines
              which   tell   their   structure.   The  first  line  tells  the  return  value  of
              Xorriso_sieve_get_result().  The next line tells the number of strings. Each string
              begins  by  a  line that tells the number of lines of the string. Then follow these
              lines. They are to be concatenated with a newline character between each  of  them.
              Finally  the  number  of  still available recorded results of the given name is put
              out.
              clear_sieve
              Dispose  all  recorded  strings  and  continue  watching  program  messages.    The
              parameter_text has no meaning.
              end_sieve
              Dispose  the  sieve  with its filter rules and stop watching program messages.  The
              parameter_text has no meaning.
              parse
              Read a  text  from  dialog  input  and  submit  it  to  Xorriso_parse_line().   The
              parameter_text word shall consist of several words separated by blanks.  It will be
              necessary to use both kinds of quotation marks.
              E.g. "'ISO session  :' '' 0 0 1"
              The   five   parameter   words   are:   prefix,   separators,   max_words,    flag,
              number_of_input_lines.   The  former  four are handed over to Xorriso_parse_line().
              The number of input lines minus one tells xorriso how many newline  characters  are
              part of the input text.
              The  announced  number  of  text lines will be read from dialog input, concatenated
              with   a   newline   character   between   each   of   them,   and   submitted   to
              Xorriso_parse_line()  as  parameter  line.  Note that newlines outside of quotation
              marks are interpreted as separators if the separators parameter is empty.
              The parsed strings are put out on result channel. They get wrapped into lines which
              tell   their   structure.    The   first   line   tells   the   return   value   of
              Xorriso_parse_line().  The next line tells  the  number  of  strings.  Each  string
              begins  by  a  line that tells the number of lines of the string. Then follow these
              lines. They are to be concatenated with a newline character between each of them.
              If -backslash_codes "encode_output" is enabled, then the strings  undergo  encoding
              as  if  they  were enclosed in quotes. Escpecially each string will be put out as a
              single result line.
              parse_bulk
              Like "parse", but with the fifth parameter word being number_of_input_texts  rather
              than number_of_input_lines. Each input text has to be preceded by a line that tells
              number_of_input_lines as with "parse".  Then come  the  announced  number  of  text
              lines.
              All input texts will be read before printing of result lines begins.  This consumes
              memory in xorriso. So the number_of_input_texts should not be  extremely  high.  On
              the  other  hand,  large  transactions  of  command,  input  texts, and results are
              desirable if connection latency is an issue.
              parse_silently
              Like "parse" but not issuing a prompting message. Confusing to humans.
              parse_bulk_silently
              Like "parse_bulk" but not issuing a prompting message. Confusing to humans.
              compare_sev
              The parameter_text should contain two comma separated severity texts as  issued  by
              this program. Like "SORRY,UPDATE". See also paragraph "Exception processing".
              These  two  severity  texts  get  compared  and a number gets printed to the result
              channel. This number is 0 if both severities are equal.  It  is  -1  if  the  first
              severity  is  lower  than  the second one.  It is 1 is the first severity is higher
              than the second one.
              Above example "SORRY,UPDATE" will yield 1.
              list_sev
              Print to the result channel a blank separated list of all severity  names.   Sorted
              from low to high severity.

       -named_pipe_loop mode[:mode] disk_path_stdin disk_path_stdout disk_path_stderr
              Temporarily  replace  standard  input,  standard output and standard error by named
              pipes. Enter dialog mode without readline.
              Defined modes are:
              "cleanup" removes the submitted pipe files when the loop ends.
              "keep" does not delete them. This is the default.
              "buffered" reads all lines from the input pipe until EOF before it opens the output
              pipes and processes the input lines.
              "direct"  opens the output pipes after the first input line was read.  Each line is
              executed directly after it is read. This is the default.
              The other three parameters must either be disk paths to existing named pipes, or be
              "-" to leave the according standard i/o channel unreplaced.
              xorriso  will  open the stdin pipe, read and execute dialog lines from it until the
              sender closes the pipe. The output pipes get opened depending on mode "buffered" or
              "direct".  After  all  lines are executed, xorriso will close its side of the pipes
              and enter a new cycle of opening, reading and executing.
              If  an  input  line  consists  only  of   the   word   "end_named_pipe_loop"   then
              -named_pipe_loop  will  end and further xorriso commands may be executed from other
              sources.

       -launch_frontend program [arguments ...] --
              Start the program that is given as first parameter. Submit the other parameters  as
              program arguments. Enable xorriso dialog mode.
              Two nameless pipe objects are created. xorriso standard input gets connected to the
              standard output of the started program.  xorriso standard output and standard error
              get connected to the standard input of that program.
              xorriso will abort when the started program ends or if it cannot be started at all.
              In both cases it will return a non-zero exit value.  The exit value will be zero if
              the frontend sends -end or -rollback_end before ending itself.
              This  command  may  be  totaly  banned  at compile time. It is banned by default if
              xorriso runs under setuid permissions.
              The program name will not be searched in  the  $PATH  directories.   To  make  this
              clear, it must contain at least one /-character.  Best is an absolute path.
              Example:
                xorriso -launch_frontend "$(which xorriso-tcltk)" -stdio --
              The frontend program should first send via its standard output:
                -mark 0 -pkt_output on -msg_op start_sieve - -reassure off
              It  should  be ready to decode -pkt_output and to react on -mark messages.  Best is
              to increment the -mark number after each sent command sequence and then to wait for
              the new number to show up in a mark message:
                ...some...commands... -mark <incremented_number>
              Further are advised:
                -report_about UPDATE -abort_on NEVER
                -iso_rr_pattern off -disk_pattern off
              A  check  of  the  xorriso  version  should be done, in order to make sure that all
              desired features are present.
              Command -launch_frontend will only work  once  per  xorriso  run.   If  no  command
              parameters  are  submitted  or if program is an empty text, then no program will be
              started but nevertheless -launch_frontend will be irrevocably disabled.

       -prog text
              Use text as name of this program in subsequent messages

       -prog_help text
              Use text as name of this program and perform -help.

EXAMPLES

   Overview of examples:
       As superuser learn about available drives
       Blank medium and compose a new ISO image as batch run
       A dialog session doing about the same
       Manipulate an existing ISO image on the same medium
       Copy modified ISO image from one medium to another
       Bring a prepared ISOLINUX tree onto medium and make it bootable
       Change existing file name tree from ISO-8859-1 to UTF-8
       Operate on storage facilities other than optical drives
       Burn an existing ISO image file to medium
       Perform multi-session runs as of cdrtools traditions
       Let xorriso work underneath growisofs
       Adjust thresholds for verbosity, exit value and program abort
       Examples of input timestrings
       Incremental backup of a few directory trees
       Restore directory trees from a particular ISO session to disk
       Try to retrieve blocks from a damaged medium

   As superuser learn about available drives
       On Linux, FreeBSD or NetBSD consider to give rw-permissions to those users or groups which
       shall be able to use the drives with xorriso.  On Solaris use pfexec. Consider to restrict
       privileges of xorriso to "base,sys_devices" and to give r-permission to user or group.
       $ xorriso -device_links
       1  -dev '/dev/cdrom1' rwrw-- :  'TSSTcorp' 'DVD-ROM SH-D162C
       1  -dev '/dev/cdrw'   rwrw-- :  'TSSTcorp' 'CDDVDW SH-S223B'
       2  -dev '/dev/cdrw3'  rwrw-- :  'HL-DT-ST' 'BDDVDRW_GGC-H20L'

   Blank medium and compose a new ISO image as batch run
       Acquire drive /dev/sr2, make medium ready for writing a new image, fill the image with the
       files from hard disk directories /home/me/sounds and /home/me/pictures.
       Because  no -dialog "on" is given, the program will then end by writing the session to the
       medium.
       $ xorriso -outdev /dev/sr2 \
        -blank as_needed \
        -map /home/me/sounds /sounds \
        -map /home/me/pictures /pictures

       The ISO image may be shaped in a more elaborate way like the following: Omit some unwanted
       stuff by removing it from the image directory tree.  Reintroduce some wanted stuff.
       $ cd /home/me
       $ xorriso -outdev /dev/sr2 \
        -blank as_needed \
        -map /home/me/sounds /sounds \
        -map /home/me/pictures /pictures \
        -rm_r \
          /sounds/indecent \
          '/pictures/*private*' \
          /pictures/confidential \
          -- \
        -cd / \
        -add pictures/confidential/work* --
       Note    that    '/pictures/*private*'    is    a    pattern    for    iso_rr_paths   while
       pictures/confidential/work* gets expanded by the shell with addresses from the hard  disk.
       Commands  -add  and  -map have different parameter rules but finally the same effect: they
       put files into the image.

   A dialog session doing about the same
       Some settings are already given as start argument. The other activities are done as dialog
       input. The pager gets set to 20 lines of 80 characters.
       The  drive  is  acquired  by  command -dev rather than -outdev in order to see the message
       about its current content. By  command  -blank  this  content  is  made  ready  for  being
       overwritten and the loaded ISO image is made empty.
       In order to be able to eject the medium, the session needs to be committed explicitly.
       $ xorriso -dialog on -page 20 80 -disk_pattern on
       enter option and arguments :
       -dev /dev/sr2
       enter option and arguments :
       -blank as_needed
       enter option and arguments :
       -map /home/me/sounds /sounds -map /home/me/pictures /pictures
       enter option and arguments :
       -rm_r /sounds/indecent /pictures/*private* /pictures/confidential
       enter option and arguments :
       -cdx /home/me/pictures -cd /pictures
       enter option and arguments :
       -add confidential/office confidential/factory
       enter option and arguments :
       -du /
       enter option and arguments :
       -commit_eject all -end

   Manipulate an existing ISO image on the same medium
       Load image from drive.  Remove (i.e. hide) directory /sounds and its subordinates.  Rename
       directory /pictures/confidential to /pictures/restricted.  Change  access  permissions  of
       directory /pictures/restricted.  Add new directory trees /sounds and /movies.  Burn to the
       same medium, check whether the tree can be loaded, and eject.
       $ xorriso -dev /dev/sr2 \
        -rm_r /sounds -- \
        -mv \
          /pictures/confidential \
          /pictures/restricted \
          -- \
        -chmod go-rwx /pictures/restricted -- \
        -map /home/me/prepared_for_dvd/sounds_dummy /sounds \
        -map /home/me/prepared_for_dvd/movies /movies \
        -commit -eject all

   Copy modified ISO image from one medium to another
       Load image from input drive. Do the same manipulations as in the previous example. Acquire
       output drive and blank it. Burn the modified image as first and only session to the output
       drive.
       $ xorriso -indev /dev/sr2 \
        -rm_r /sounds -- \
        ...
        -outdev /dev/sr0 -blank as_needed \
        -commit -eject all

   Bring a prepared ISOLINUX tree onto medium and make it bootable
       The user has already created a suitable file tree on disk and copied  the  ISOLINUX  files
       into  subdirectory  ./boot/isolinux  of  that  tree.   Now  xorriso  can burn an El Torito
       bootable medium:
       $ xorriso -outdev /dev/sr0 -blank as_needed \
          -map /home/me/ISOLINUX_prepared_tree / \
          -boot_image isolinux dir=/boot/isolinux

   Change existing file name tree from ISO-8859-1 to UTF-8
       This example assumes that the existing ISO image was written with character set ISO-8859-1
       but  that  the  readers  expected  UTF-8. Now a new session gets added with converted file
       names.   Command  -changes_pending  "yes"  enables  writing  despite  the  lack   of   any
       manipulation command.
       In order to avoid any weaknesses of the local character set, this command pretends that it
       uses already the final target set UTF-8.  Therefore  strange  file  names  may  appear  in
       messages, which will be made terminal-safe by command -backslash_codes.
       $ xorriso -in_charset ISO-8859-1 -local_charset UTF-8 \
          -out_charset UTF-8 -backslash_codes on -dev /dev/sr0 \
          -changes_pending yes -commit -eject all

   Operate on storage facilities other than optical drives
       Full read-write operation is possible with regular files and block devices:
       $ xorriso -dev /tmp/regular_file ...
       Paths underneath /dev normally need prefix "stdio:"
       $ xorriso -dev stdio:/dev/sdb ...
       If  /dev/sdb  is  to  be used frequently and /dev/sda is the system disk, then consider to
       place the following lines in a xorriso Startup File.   They  allow  you  to  use  /dev/sdb
       without prefix and protect disk /dev/sda from xorriso:
         -drive_class banned   /dev/sda*
         -drive_class harmless /dev/sdb
       Other writeable file types are supported write-only:
       $ xorriso -outdev /tmp/named_pipe ...
       Among the write-only drives is standard output:
       $ xorriso -outdev - \
        ...
        | gzip >image.iso.gz

   Burn an existing ISO image file to medium
       Actually this works with any kind of data, not only ISO images:
       $ xorriso -as cdrecord -v dev=/dev/sr0 blank=as_needed image.iso

   Perform multi-session runs as of cdrtools traditions
       Between both processes there can be performed arbitrary transportation or filtering.
       The first session is written like this:
       $ xorriso -as mkisofs prepared_for_iso/tree1 | \
        xorriso -as cdrecord -v dev=/dev/sr0 blank=fast -multi -eject -
       Follow-up sessions are written like this:
       $ dd if=/dev/sr0 count=1 >/dev/null 2>&1
       $ m=$(xorriso -as cdrecord dev=/dev/sr0 -msinfo)
       $ xorriso -as mkisofs -M /dev/sr0 -C $m prepared_for_iso/tree2 | \
        xorriso -as cdrecord -v dev=/dev/sr0 -waiti -multi -eject -
       Always  eject the drive tray between sessions. The old sessions get read via /dev/sr0. Its
       device driver might not be aware of the changed content before it loads the medium  again.
       In  this  case  the previous session would not be loaded and the new session would contain
       only the newly added files.
       For the same reason do not let xorriso -as cdrecord load the medium, but  rather  do  this
       manually or by a program that reads from /dev/sr0.
       This    example    works    for    multi-session   media   only.    Add   cdrskin   option
       --grow_overwriteable_iso to all  -as  cdrecord  runs  in  order  to  enable  multi-session
       emulation on overwriteable media.

   Let xorriso work underneath growisofs
       growisofs expects an ISO formatter program which understands options -C and -M. If xorriso
       gets started by name "xorrisofs" then it is suitable for that.
       $ export MKISOFS="xorrisofs"
       $ growisofs -Z /dev/dvd /some/files
       $ growisofs -M /dev/dvd /more/files
       If no "xorrisofs" is available on your system,  then  you  will  have  to  create  a  link
       pointing to the xorriso binary and tell growisofs to use it.  E.g. by:
       $ ln -s $(which xorriso) "$HOME/xorrisofs"
       $ export MKISOFS="$HOME/xorrisofs"
       One  may  quit  mkisofs  emulation  by argument "--" and make use of all xorriso commands.
       growisofs dislikes options which start with "-o" but -outdev must be set to "-".   So  use
       "outdev" instead:
       $ growisofs -Z /dev/dvd -- outdev - -update_r /my/files /files
       $ growisofs -M /dev/dvd -- outdev - -update_r /my/files /files
       growisofs  has  excellent  burn capabilities with DVD and BD.  It does not emulate session
       history on overwriteable media, though.

   Adjust thresholds for verbosity, exit value and program abort
       Be quite verbous, exit 32 if severity "FAILURE" was encountered, do not abort  prematurely
       but forcibly go on until the end of commands.
       $ xorriso ... \
        -report_about UPDATE \
        -return_with FAILURE 32 \
        -abort_on NEVER \
        ...

   Examples of input timestrings
       As printed by program date: 'Thu Nov 8 14:51:13 CET 2007'
       The same without ignored parts: 'Nov 8 14:51:13 2007'
       The same as expected by date: 110814512007.13
       Four weeks in the future: +4w
       The current time: +0
       Three hours ago: -3h
       Seconds since Jan 1 1970: =1194531416

   Incremental backup of a few directory trees
       This  changes  the  directory  trees /projects and /personal_mail in the ISO image so that
       they become exact copies of their  disk  counterparts.   ISO  file  objects  get  created,
       deleted or get their attributes adjusted accordingly.
       ACL,  xattr,  hard  links  and  MD5 checksums will be recorded.  Accelerated comparison is
       enabled at the expense of potentially larger backup size. Only  media  with  the  expected
       volume  ID  or  blank  media  are  accepted.   Files  with names matching *.o or *.swp get
       excluded explicitly.
       When done with writing the new session gets checked by its recorded MD5.
       $ xorriso \
        -abort_on FATAL \
        -for_backup -disk_dev_ino on \
        -assert_volid 'PROJECTS_MAIL_*' FATAL \
        -dev /dev/sr0 \
        -volid PROJECTS_MAIL_"$(date '+%Y_%m_%d_%H%M%S')" \
        -not_leaf '*.o' -not_leaf '*.swp' \
        -update_r /home/thomas/projects /projects \
        -update_r /home/thomas/personal_mail /personal_mail \
        -commit -toc -check_md5 FAILURE -- -eject all
       To be used several times on the same medium, whenever an update of the two disk  trees  to
       the  medium  is  desired.  Begin  with  a  blank  medium and update it until the run fails
       gracefully due to lack of remaining space on the old one.
       This makes sense if the full backup leaves substantial remaining capacity on media and  if
       the  expected  changes are much smaller than the full backup.  To apply zisofs compression
       to those data files which get  newly  copied  from  the  local  filesystem,  insert  these
       commands immediately before -commit :
        -hardlinks perform_update \
        -find / -type f -pending_data -exec set_filter --zisofs -- \
       Commands  -disk_dev_ino and -for_backup depend on stable device and inode numbers on disk.
       Without them, an update run may use -md5 "on" to  match  recorded  MD5  sums  against  the
       current  file  content  on  hard  disk. This is usually much faster than the default which
       compares both contents directly.
       With mount option -o "sbsector=" on GNU/Linux or -s on FreeBSD or NetBSD it is possible to
       access  the  session  trees  which  represent  the  older  backup versions. With CD media,
       GNU/Linux mount accepts session numbers directly by its option "session=".
       Multi-session media and most overwriteable media written by xorriso can tell the sbsectors
       of  their  sessions  by  xorriso  command  -toc.  Used after -commit the following command
       prints the matching mount command for the newly written  session  (here  for  mount  point
       /mnt):
        -mount_cmd "indev" "auto" "auto" /mnt
       Commands  -mount_cmd  and  -mount  are  also  able to produce the mount commands for older
       sessions in the table-of-content. E.g. as superuser:
        # osirrox -mount /dev/sr0 "volid" '*2008_12_05*' /mnt

       Above example produces a result similar to  -root / -old-root / with mkisofs.  For getting
       the  session  trees accumulated in the new sessions, let all -update commands use a common
       parent directory and clone it after updating is done:
        -update_r /home/thomas/projects /current/projects \
        -update_r /home/thomas/personal_mail /current/personal_mail \
        -clone /current /"$(date '+%Y_%m_%d_%H%M%S')" \
       The cloned tree will have a name like /2011_02_12_155700.

       Sessions on multi-session media are separated by several MB of  unused  blocks.   So  with
       small  sessions the payload capacity can become substantially lower than the overall media
       capacity. If the remaining space on a medium does not suffice for the next gap, the  drive
       is supposed to close the medium automatically.

       Better  do  not use your youngest backup for -update_r.  Have at least two media which you
       use alternatingly. So only older backups get endangered by the new write operation,  while
       the newest backup is stored safely on a different medium.
       Always have a blank medium ready to perform a full backup in case the update attempt fails
       due to insufficient remaining capacity. This failure will not spoil  the  old  medium,  of
       course.

   Restore directory trees from a particular ISO session to disk
       This is an alternative to mounting the medium and using normal file operations.
       First check which backup sessions are on the medium:
       $ xorriso -outdev /dev/sr0 -toc
       Then  enable restoring of ACL, xattr and hard links. Load the desired session and copy the
       file trees to disk.  Avoid to create /home/thomas/restored without rwx-permission.
       $ xorriso -for_backup \
        -load volid 'PROJECTS_MAIL_2008_06_19*' \
        -indev /dev/sr0 \
        -osirrox on:auto_chmod_on \
        -chmod u+rwx / -- \
        -extract /projects /home/thomas/restored/projects \
        -extract /personal_mail /home/thomas/restored/personal_mail \
        -rollback_end
       The final command -rollback_end prevents an error message about the  altered  image  being
       discarded.

   Try to retrieve blocks from a damaged medium
       $ xorriso -abort_on NEVER -indev /dev/sr0 \
        -check_media time_limit=1800 report=blocks_files \
        data_to="$HOME"/dvd_copy sector_map="$HOME"/dvd_copy.map --
       This  can be repeated several times, if necessary with -eject or with other -indev drives.
       See the human readable part of "$HOME"/dvd_copy.map for addresses which  can  be  used  on
       "$HOME"/dvd_copy with mount option -o sbsector= or -s.

FILES

   Program alias names:
       Normal  installation  of xorriso creates three links or copies which by their program name
       pre-select certain settings:
       xorrisofs starts xorriso with -as mkisofs emulation.
       xorrecord starts xorriso with -as cdrecord emulation.
       osirrox starts with -osirrox "on:o_excl_off" which allows further commands to  copy  files
       from  ISO  image  to  disk  and to apply command -mount to one or more of the existing ISO
       sessions.

   Startup files:
       If not -no_rc is given as the first argument then xorriso attempts on startup to read  and
       execute lines from the following files:
          /etc/default/xorriso
          /etc/opt/xorriso/rc
          /etc/xorriso/xorriso.conf
          $HOME/.xorrisorc
       The files are read in the sequence given above, but none of them is required to exist. The
       line format is described with command -options_from_file.
       If mkisofs emulation was enabled by program name "xorrisofs", "mkisofs", "genisoimage", or
       "genisofs",  then  afterwards  -read_mkisofsrc is performed, which reads .mkisofsrc files.
       See there.

   Runtime control files:
       The default setting of -check_media abort_file= is:
          /var/opt/xorriso/do_abort_check_media

ENVIRONMENT

       The following environment variables influence the program behavior:
       HOME is used to find startup files of xorriso and mkisofs.
       SOURCE_DATE_EPOCH belongs to the specs of reproducible-builds.org.  It is supposed  to  be
       either  undefined or to contain a decimal number which tells the seconds since january 1st
       1970. If it contains a number, then it is used as time value to set the default of -volume
       date   "uuid",   sets   -boot_image  "any"  "gpt_disk_guid="  to  "volume_date_uuid",  and
       -volume_date "all_file_dates" to "set_to_mtime",
       Startup files and program options can override the effect of SOURCE_DATE_EPOCH.

SEE ALSO

       For the mkisofs emulation of xorriso
              xorrisofs(1)

       For the cdrecord emulation of xorriso
              xorrecord(1)

       For mounting xorriso generated ISO 9660 images (-t iso9660)
              mount(8)

       Libreadline, a comfortable input line facility
              readline(3)

       Other programs which produce ISO 9660 images
              mkisofs(8), genisoimage(1)

       Other programs which burn sessions to optical media
              growisofs(1), cdrecord(1), wodim(1), cdrskin(1)

       ACL and xattr
              getfacl(1), setfacl(1), getfattr(1), setfattr(1)

       MD5 checksums
              md5sum(1)

       On FreeBSD the commands for xattr and MD5 differ
              getextattr(8), setextattr(8), md5(1)

BUGS

       To report bugs, request help, or suggest enhancements for xorriso, please send  electronic
       mail  to  the  public  list  <bug-xorriso@gnu.org>.   If  more privacy is desired, mail to
       <scdbackup@gmx.net>.
       Please describe what you expect xorriso to do, the program arguments or dialog commands by
       which  you  tried  to  achieve it, the messages of xorriso, and the undesirable outcome of
       your program run.
       Expect to get asked more questions before solutions can be proposed.

AUTHOR

       Thomas Schmitt <scdbackup@gmx.net>
       for libburnia-project.org

COPYRIGHT

       Copyright (c) 2007 - 2018 Thomas Schmitt
       Permission is granted to distribute this text freely. It shall only be  modified  in  sync
       with  the  technical  properties  of  xorriso.   If  you make use of the license to derive
       modified versions of xorriso then you are entitled to modify this  text  under  that  same
       license.

CREDITS

       xorriso  is  in  part  based on work by Vreixo Formoso who provides libisofs together with
       Mario Danic who also leads the libburnia team.  Vladimir Serbinenko contributed  the  HFS+
       filesystem  code  and  related  knowledge.   Thanks to Andy Polyakov who invented emulated
       growing, to Derek Foreman and Ben Jansens who once founded libburn.
       Compliments towards Joerg Schilling whose cdrtools served me for ten years.

                                   Version 1.5.0, Sep 15, 2018                         XORRISO(1)