Provided by: xorriso_1.5.2-1_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.

       -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.

       -drive_access "exclusive"|"shared":"unrestricted"|"readonly"
              Control whether device file locking mechanisms shall be used when acquiring a drive,  and  whether
              status  or  content  of  the  medium in the drive may be altered. Useful and most harmless are the
              setting "shared:readonly" and the default setting "exclusive:unrestricted".
              "exclusive" enables tests and locks when acquiring the drive. It depends on the  operating  system
              which  locking  mechanisms  get applied, if any. On GNU/Linux it is open(O_EXCL). On FreeBSD it is
              flock(LOCK_EX).
              "shared" disables the use of these mechanisms to become able to acquire drives which are  mounted,
              or opened by some process, or guarded by /dev/pktcdvd*.
              "unrestricted"   enables   all   technically   appropriate   operations   on  an  acquired  drive.
              "shared:unrestricted" risks to get own burn runs spoiled by other processes or to vice versa spoil
              activities  of  such  processes.  So  use  "exclusive:unrestricted"  unless you know for sure that
              "shared" is safe.
              "readonly" disables operations which might surprise a co-user of the drive.  For -outdev these are
              formatting,  blanking,  writing, ejecting. For -indev this is ejecting. Be aware that even reading
              and drive status inquiries can disturb an ongoing burn run on CD-R[W] and DVD-R[W].

       -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.

       -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 administrator 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.

       -iso_nowtime "dynamic"|timestring
              Choose  whether  to  use  the current time ("dynamic") or a fixed time point for timestamps of ISO
              9660 nodes without a disk source file and as default for superblock timestamps.
              If a timestring is given, then it is used for such timestamps. For the formats of timestrings  see
              command -alter_date.

       -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 -osirrox 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 command -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.
              If instead a type_guid is given by a 32-digit hex string like a2a0d0ebe5b9334487c068b6b72699c7  or
              by  a structured text like EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, then it will be used as partition
              type    if    the    ISO    filesystem    appears    as    partition    in    GPT.     In     MBR,
              C12A7328-F81F-11D2-BA4B-00A0C93EC93B  will  be  mapped  to 0xef.  Any other GUID will be mapped to
              0x83.
              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 MBR partition type codes search the
              Internet for "Partition Types" or run fdisk command "L".
              type_code may also be a type GUID as plain hex string like a2a0d0ebe5b9334487c068b6b72699c7 or  as
              structured  text  like  EBD0A0A2-B9E5-4433-87C0-68B6B72699C7.  It will be used if the partition is
              mentioned in GPT. In MBR, C12A7328-F81F-11D2-BA4B-00A0C93EC93B will be mapped to 0xef.  Any  other
              GUID will be mapped to 0x83.
              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  checksum
       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 checksum file by a single text line:
       Checksum as hex digits, 2 blanks, size as 12 decimal digits or blanks, 2 blanks, symbolic file address
       The kind of checksum is chosen by -jigdo "checksum_algorithm"  with  values  "md5"  (32  hex  digits)  or
       "sha256"  (64  hex  digits).   It  will  also be used for the file address lines in the .jigdo file.  The
       default is "md5".
       The file address in a checksum file 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.
              checksum_algorithm chooses the checksum algorithm which shall be used for the data file entries in
              the .jigdo file and is expected in the checksum file. Permissible are "md5" or  "sha256".  Default
              is "md5".
              Alias: -jigdo-checksum-algorithm
              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
              checksum_path  sets the disk_path where to find the checksum file with symbolic file addresses and
              checksums according to checksum_algorithm.
              Alias: md5_path
              Alias: -checksum-list
              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_checksum adds a regular expression pattern  which  will  get  compared  with  the  absolute
              disk_path  of  any data file that was not found in the checksum list file as of "checksum_path". A
              match causes a MISHAP event.
              Alias: demand_md5
              Alias: -jigdo-force-checksum
              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 checksum 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.
              By default bad_limit is set higher than md5_mismatch, so that mismatches are classified as quality
              class "0" rather than "-". This means that the sectors of a MD5 mismatch range are recorded in the
              sector_map as successfully read, if the drive handed them out at all. Set "bad_limit=md5_mismatch"
              to let the sector_map record the whole mismatching range as yet not retrieved.
              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 by the equivalent of  -drive_access
              "shared:readonly".  I.e.  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 verbose 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 (the run of dd is only to give demons a chance to spoil it):
       $ m=$(xorriso -as cdrecord dev=/dev/sr0 -msinfo)
       $ dd if=/dev/sr0 count=1 >/dev/null 2>&1
       $ 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  run  of  xorriso  -as  mkisofs will read old sessions via the CD-ROM driver of /dev/sr0. This driver
       might not be aware of the changed content as long as the medium is not loaded again.  In  this  case  the
       previous  session  would  not  be properly assessed by xorriso and the new session would contain only the
       newly added files.
       Some systems have not enough patience with automatic tray loading and some demons may  interfere  with  a
       first CD-ROM driver read attempt from a freshly loaded medium.
       When loading the tray manually, wait 10 seconds after the drive has stopped blinking.
       A  safe automatic way seems to be a separate run of xorriso for loading the tray with proper waiting, and
       a subsequent run of dd which shall offer itself to any problems caused by demons  assessing  the  changed
       drive status.  If this does not help, insert a run of "sleep 10" between xorriso and dd.
       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 verbose, 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", -volume_date "all_file_dates" to "set_to_mtime", and -iso_nowtime
       to "=$SOURCE_DATE_EPOCH".
       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 - 2019 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 1.5.2, Nov 26, 2019                                XORRISO(1)