Provided by: unzip_6.0-4ubuntu1_amd64 bug

NAME

       unzip - list, test and extract compressed files in a ZIP archive

SYNOPSIS

       unzip  [-Z] [-cflptTuvz[abjnoqsCDKLMUVWX$/:^]] file[.zip] [file(s) ...]  [-x xfile(s) ...]
       [-d exdir]

DESCRIPTION

       unzip will list, test, or extract files from a  ZIP  archive,  commonly  found  on  MS-DOS
       systems.   The default behavior (with no options) is to extract into the current directory
       (and subdirectories below it) all files from  the  specified  ZIP  archive.   A  companion
       program,  zip(1), creates ZIP archives; both programs are compatible with archives created
       by PKWARE's PKZIP and PKUNZIP for MS-DOS, but in many cases the program options or default
       behaviors differ.

ARGUMENTS

       file[.zip]
              Path of the ZIP archive(s).  If the file specification is a wildcard, each matching
              file is processed in an order determined by the operating system (or file  system).
              Only  the filename can be a wildcard; the path itself cannot.  Wildcard expressions
              are similar to those supported in commonly used Unix shells (sh, ksh, csh) and  may
              contain:

              *      matches a sequence of 0 or more characters

              ?      matches exactly 1 character

              [...]  matches any single character found inside the brackets; ranges are specified
                     by a beginning  character,  a  hyphen,  and  an  ending  character.   If  an
                     exclamation point or a caret (`!' or `^') follows the left bracket, then the
                     range of characters within the brackets is complemented (that  is,  anything
                     except  the  characters  inside  the  brackets  is  considered a match).  To
                     specify a verbatim left bracket, the three-character sequence ``[[]'' has to
                     be used.

              (Be  sure to quote any character that might otherwise be interpreted or modified by
              the operating system, particularly under Unix and VMS.)  If no matches  are  found,
              the  specification is assumed to be a literal filename; and if that also fails, the
              suffix .zip is appended.  Note that self-extracting ZIP  files  are  supported,  as
              with any other ZIP archive; just specify the .exe suffix (if any) explicitly.

       [file(s)]
              An  optional  list  of  archive members to be processed, separated by spaces.  (VMS
              versions compiled with VMSCLI defined must delimit files with commas instead.   See
              -v  in  OPTIONS  below.)   Regular  expressions  (wildcards)  may  be used to match
              multiple members; see above.  Again,  be  sure  to  quote  expressions  that  would
              otherwise be expanded or modified by the operating system.

       [-x xfile(s)]
              An optional list of archive members to be excluded from processing.  Since wildcard
              characters normally match (`/') directory separators (for exceptions see the option
              -W),  this option may be used to exclude any files that are in subdirectories.  For
              example, ``unzip foo *.[ch] -x */*'' would extract all C source files in  the  main
              directory,  but  none  in  any subdirectories.  Without the -x option, all C source
              files in all directories within the zipfile would be extracted.

       [-d exdir]
              An optional directory to which  to  extract  files.   By  default,  all  files  and
              subdirectories  are  recreated  in  the  current  directory;  the  -d option allows
              extraction in an arbitrary directory (always assuming one has permission  to  write
              to  the directory).  This option need not appear at the end of the command line; it
              is also accepted before  the  zipfile  specification  (with  the  normal  options),
              immediately  after  the  zipfile  specification,  or between the file(s) and the -x
              option.  The option and directory may  be  concatenated  without  any  white  space
              between  them, but note that this may cause normal shell behavior to be suppressed.
              In particular, ``-d ~'' (tilde) is expanded by Unix C shells into the name  of  the
              user's  home  directory,  but ``-d~'' is treated as a literal subdirectory ``~'' of
              the current directory.

OPTIONS

       Note that, in order to support obsolescent hardware, unzip's usage screen is limited to 22
       or  23  lines and should therefore be considered only a reminder of the basic unzip syntax
       rather than an exhaustive list of all possible flags.  The exhaustive list follows:

       -Z     zipinfo(1) mode.  If the first option on the command  line  is  -Z,  the  remaining
              options  are taken to be zipinfo(1) options.  See the appropriate manual page for a
              description of these options.

       -A     [OS/2, Unix DLL] print extended help for the DLL's programming interface (API).

       -c     extract files to stdout/screen (``CRT'').  This option is similar to the -p  option
              except  that  the name of each file is printed as it is extracted, the -a option is
              allowed, and ASCII-EBCDIC conversion is  automatically  performed  if  appropriate.
              This option is not listed in the unzip usage screen.

       -f     freshen  existing  files, i.e., extract only those files that already exist on disk
              and that are  newer  than  the  disk  copies.   By  default  unzip  queries  before
              overwriting,  but  the  -o  option  may be used to suppress the queries.  Note that
              under many operating systems, the TZ (timezone) environment variable  must  be  set
              correctly  in  order  for  -f  and  -u to work properly (under Unix the variable is
              usually set automatically).  The reasons for this are somewhat subtle but  have  to
              do with the differences between DOS-format file times (always local time) and Unix-
              format times (always in GMT/UTC) and the necessity to compare the two.   A  typical
              TZ  value  is  ``PST8PDT''  (US Pacific time with automatic adjustment for Daylight
              Savings Time or ``summer time'').

       -l     list archive  files  (short  format).   The  names,  uncompressed  file  sizes  and
              modification  dates and times of the specified files are printed, along with totals
              for all files specified.  If UnZip was compiled with OS2_EAS defined, the -l option
              also  lists columns for the sizes of stored OS/2 extended attributes (EAs) and OS/2
              access control lists (ACLs).  In addition, the zipfile comment and individual  file
              comments  (if  any)  are displayed.  If a file was archived from a single-case file
              system (for example, the old MS-DOS FAT file system) and the -L option  was  given,
              the filename is converted to lowercase and is prefixed with a caret (^).

       -p     extract  files  to pipe (stdout).  Nothing but the file data is sent to stdout, and
              the files are always extracted in binary  format,  just  as  they  are  stored  (no
              conversions).

       -t     test  archive  files.   This  option  extracts  each  specified  file in memory and
              compares the CRC (cyclic redundancy check, an enhanced checksum)  of  the  expanded
              file with the original file's stored CRC value.

       -T     [most  OSes] set the timestamp on the archive(s) to that of the newest file in each
              one.  This corresponds to zip's -go option except that it can be used  on  wildcard
              zipfiles (e.g., ``unzip -T \*.zip'') and is much faster.

       -u     update existing files and create new ones if needed.  This option performs the same
              function as the -f option, extracting (with query) files that are newer than  those
              with  the  same  name  on disk, and in addition it extracts those files that do not
              already exist on disk.  See -f  above  for  information  on  setting  the  timezone
              properly.

       -v     list  archive  files (verbose format) or show diagnostic version info.  This option
              has evolved and now behaves as both an option and a modifier.  As an option it  has
              two  purposes:  when a zipfile is specified with no other options, -v lists archive
              files verbosely, adding to the basic -l info  the  compression  method,  compressed
              size,  compression  ratio  and  32-bit  CRC.   In contrast to most of the competing
              utilities, unzip removes the 12 additional header bytes of encrypted  entries  from
              the  compressed  size  numbers.   Therefore,  compressed size and compression ratio
              figures are independent of the entry's  encryption  status  and  show  the  correct
              compression  performance.   (The  complete  size  of  the encrypted compressed data
              stream for zipfile entries is reported by the more verbose zipinfo(1) reports,  see
              the  separate manual.)  When no zipfile is specified (that is, the complete command
              is simply ``unzip -v''), a diagnostic screen is printed.  In addition to the normal
              header  with  release  date and version, unzip lists the home Info-ZIP ftp site and
              where to find a list of other ftp and non-ftp sites; the  target  operating  system
              for  which  it  was  compiled,  as  well as (possibly) the hardware on which it was
              compiled, the compiler and version used, and  the  compilation  date;  any  special
              compilation  options that might affect the program's operation (see also DECRYPTION
              below); and any options stored in environment variables that might do the same (see
              ENVIRONMENT  OPTIONS  below).   As  a  modifier  it works in conjunction with other
              options (e.g., -t) to produce more verbose or debugging output;  this  is  not  yet
              fully implemented but will be in future releases.

       -z     display only the archive comment.

MODIFIERS

       -a     convert  text files.  Ordinarily all files are extracted exactly as they are stored
              (as ``binary'' files).  The -a option causes files identified by zip as text  files
              (those with the `t' label in zipinfo listings, rather than `b') to be automatically
              extracted  as  such,  converting  line  endings,  end-of-file  characters  and  the
              character  set  itself as necessary.  (For example, Unix files use line feeds (LFs)
              for end-of-line (EOL)  and  have  no  end-of-file  (EOF)  marker;  Macintoshes  use
              carriage  returns  (CRs) for EOLs; and most PC operating systems use CR+LF for EOLs
              and control-Z for EOF.  In addition,  IBM  mainframes  and  the  Michigan  Terminal
              System  use EBCDIC rather than the more common ASCII character set, and NT supports
              Unicode.)  Note that zip's identification of text files is  by  no  means  perfect;
              some  ``text'' files may actually be binary and vice versa.  unzip therefore prints
              ``[text]'' or ``[binary]'' as a visual check for each file it extracts  when  using
              the -a option.  The -aa option forces all files to be extracted as text, regardless
              of the supposed file type.  On VMS, see also -S.

       -b     [general] treat all files as binary (no text conversions).  This is a shortcut  for
              ---a.

       -b     [Tandem]  force the creation files with filecode type 180 ('C') when extracting Zip
              entries marked as "text". (On Tandem, -a is enabled by default, see above).

       -b     [VMS] auto-convert binary files (see -a above)  to  fixed-length,  512-byte  record
              format.  Doubling the option (-bb) forces all files to be extracted in this format.
              When extracting to standard output  (-c  or  -p  option  in  effect),  the  default
              conversion  of  text  record delimiters is disabled for binary (-b) resp. all (-bb)
              files.

       -B     [when compiled with UNIXBACKUP defined] save a  backup  copy  of  each  overwritten
              file.  The  backup  file  is  gets  the  name  of  the target file with a tilde and
              optionally a unique sequence number (up to 5 digits) appended.  The sequence number
              is  applied whenever another file with the original name plus tilde already exists.
              When used together with the "overwrite all" option -o, numbered  backup  files  are
              never  created.  In this case, all backup files are named as the original file with
              an appended tilde, existing backup files are deleted without notice.  This  feature
              works similarly to the default behavior of emacs(1) in many locations.

              Example: the old copy of ``foo'' is renamed to ``foo~''.

              Warning: Users should be aware that the -B option does not prevent loss of existing
              data under all circumstances.  For example, when  unzip  is  run  in  overwrite-all
              mode,  an existing ``foo~'' file is deleted before unzip attempts to rename ``foo''
              to ``foo~''.  When this rename attempt fails (because of a file locks, insufficient
              privileges,  or ...), the extraction of ``foo~'' gets cancelled, but the old backup
              file is already lost.  A similar scenario takes  place  when  the  sequence  number
              range  for  numbered  backup  files  gets  exhausted  (99999,  or  65535 for 16-bit
              systems).  In this case, the backup  file  with  the  maximum  sequence  number  is
              deleted and replaced by the new backup version without notice.

       -C     use  case-insensitive  matching  for  the  selection  of  archive  entries from the
              command-line list of extract selection patterns.  unzip's philosophy is  ``you  get
              what you ask for'' (this is also responsible for the -L/-U change; see the relevant
              options below).  Because some file systems are fully case-sensitive (notably  those
              under the Unix operating system) and because both ZIP archives and unzip itself are
              portable across platforms, unzip's default behavior is to match both  wildcard  and
              literal  filenames  case-sensitively.   That  is,  specifying  ``makefile''  on the
              command line will only match ``makefile''  in  the  archive,  not  ``Makefile''  or
              ``MAKEFILE''  (and  similarly  for  wildcard  specifications).  Since this does not
              correspond to the behavior of many other operating/file systems (for example,  OS/2
              HPFS,  which preserves mixed case but is not sensitive to it), the -C option may be
              used to force all filename matches to be case-insensitive.  In the  example  above,
              all  three  files would then match ``makefile'' (or ``make*'', or similar).  The -C
              option affects file specs in both the normal file list and the  excluded-file  list
              (xlist).

              Please  note  that  the -C option does neither affect the search for the zipfile(s)
              nor the matching of archive entries to existing files on the extraction path.  On a
              case-sensitive  file  system, unzip will never try to overwrite a file ``FOO'' when
              extracting an entry ``foo''!

       -D     skip restoration of timestamps for  extracted  items.   Normally,  unzip  tries  to
              restore  all  meta-information  for  extracted  items  that are supplied in the Zip
              archive (and do not require privileges or impose a security risk).   By  specifying
              -D,  unzip is told to suppress restoration of timestamps for directories explicitly
              created from Zip archive entries.  This option only applies to ports  that  support
              setting timestamps for directories (currently ATheOS, BeOS, MacOS, OS/2, Unix, VMS,
              Win32, for other unzip ports, -D has no effect).  The duplicated option -DD  forces
              suppression   of  timestamp  restoration  for  all  extracted  entries  (files  and
              directories).  This option results in setting  the  timestamps  for  all  extracted
              entries to the current time.

              On  VMS,  the  default  setting  for  this  option  is  -D for consistency with the
              behaviour  of  BACKUP:  file  timestamps  are  restored,  timestamps  of  extracted
              directories  are  left  at  the  current  time.  To enable restoration of directory
              timestamps, the negated option --D should be specified.   On  VMS,  the  option  -D
              disables  timestamp  restoration  for  all  extracted  Zip archive items.  (Here, a
              single -D on the command line combines with the default -D to do what  an  explicit
              -DD does on other systems.)

       -E     [MacOS only] display contents of MacOS extra field during restore operation.

       -F     [Acorn only] suppress removal of NFS filetype extension from stored filenames.

       -F     [non-Acorn  systems  supporting  long  filenames  with embedded commas, and only if
              compiled with ACORN_FTYPE_NFS defined] translate filetype  information  from  ACORN
              RISC OS extra field blocks into a NFS filetype extension and append it to the names
              of the extracted files.  (When the stored  filename  appears  to  already  have  an
              appended NFS filetype extension, it is replaced by the info from the extra field.)

       -i     [MacOS  only]  ignore  filenames  stored  in  MacOS extra fields. Instead, the most
              compatible filename stored in the generic part of the entry's header is used.

       -j     junk paths.  The archive's directory structure is  not  recreated;  all  files  are
              deposited in the extraction directory (by default, the current one).

       -J     [BeOS  only]  junk  file  attributes.   The  file's  BeOS  file  attributes are not
              restored, just the file's data.

       -J     [MacOS only] ignore MacOS extra fields.  All Macintosh specific  info  is  skipped.
              Data-fork and resource-fork are restored as separate files.

       -K     [AtheOS,  BeOS,  Unix  only]  retain SUID/SGID/Tacky file attributes.  Without this
              flag, these attribute bits are cleared for security reasons.

       -L     convert to lowercase any filename originating on an uppercase-only operating system
              or  file system.  (This was unzip's default behavior in releases prior to 5.11; the
              new default behavior is identical to the old behavior with the -U option, which  is
              now  obsolete and will be removed in a future release.)  Depending on the archiver,
              files archived under single-case file systems (VMS, old MS-DOS FAT,  etc.)  may  be
              stored  as all-uppercase names; this can be ugly or inconvenient when extracting to
              a case-preserving file system such as OS/2 HPFS or a  case-sensitive  one  such  as
              under  Unix.  By default unzip lists and extracts such filenames exactly as they're
              stored (excepting truncation, conversion of  unsupported  characters,  etc.);  this
              option  causes  the  names  of  all  files  from certain systems to be converted to
              lowercase.  The -LL option  forces  conversion  of  every  filename  to  lowercase,
              regardless of the originating file system.

       -M     pipe  all output through an internal pager similar to the Unix more(1) command.  At
              the end of a screenful of output, unzip pauses with a ``--More--'' prompt; the next
              screenful may be viewed by pressing the Enter (Return) key or the space bar.  unzip
              can be terminated by pressing the ``q'' key and, on some systems, the  Enter/Return
              key.   Unlike  Unix  more(1),  there is no forward-searching or editing capability.
              Also, unzip doesn't  notice  if  long  lines  wrap  at  the  edge  of  the  screen,
              effectively  resulting in the printing of two or more lines and the likelihood that
              some text will scroll off the top of the  screen  before  being  viewed.   On  some
              systems  the number of available lines on the screen is not detected, in which case
              unzip assumes the height is 24 lines.

       -n     never overwrite existing files.  If a file already exists, skip the  extraction  of
              that  file  without prompting.  By default unzip queries before extracting any file
              that already exists; the user may  choose  to  overwrite  only  the  current  file,
              overwrite  all  files,  skip extraction of the current file, skip extraction of all
              existing files, or rename the current file.

       -N     [Amiga] extract file comments as Amiga filenotes.  File comments are  created  with
              the  -c  option of zip(1), or with the -N option of the Amiga port of zip(1), which
              stores filenotes as comments.

       -o     overwrite existing files without prompting.  This is a dangerous option, so use  it
              with  care.   (It  is often used with -f, however, and is the only way to overwrite
              directory EAs under OS/2.)

       -P password
              use password to decrypt encrypted zipfile entries  (if  any).   THIS  IS  INSECURE!
              Many  multi-user  operating  systems  provide  ways for any user to see the current
              command line of any other user; even on stand-alone systems  there  is  always  the
              threat  of  over-the-shoulder peeking.  Storing the plaintext password as part of a
              command line in an automated script is even worse.  Whenever possible, use the non-
              echoing,  interactive  prompt  to  enter  passwords.   (And where security is truly
              important, use strong encryption  such  as  Pretty  Good  Privacy  instead  of  the
              relatively weak encryption provided by standard zipfile utilities.)

       -q     perform operations quietly (-qq = even quieter).  Ordinarily unzip prints the names
              of the files it's extracting or  testing,  the  extraction  methods,  any  file  or
              zipfile  comments  that  may  be stored in the archive, and possibly a summary when
              finished with each archive.  The -q[q] options suppress the printing of some or all
              of these messages.

       -s     [OS/2,  NT,  MS-DOS]  convert  spaces  in  filenames  to underscores.  Since all PC
              operating systems allow spaces in filenames, unzip by  default  extracts  filenames
              with  spaces  intact  (e.g., ``EA DATA. SF'').  This can be awkward, however, since
              MS-DOS in particular does not gracefully support spaces in  filenames.   Conversion
              of spaces to underscores can eliminate the awkwardness in some cases.

       -S     [VMS]  convert  text  files  (-a, -aa) into Stream_LF record format, instead of the
              text-file default, variable-length record format.  (Stream_LF is the default record
              format  of  VMS  unzip. It is applied unless conversion (-a, -aa and/or -b, -bb) is
              requested or a VMS-specific entry is processed.)

       -U     [UNICODE_SUPPORT only] modify or disable UTF-8 handling.  When  UNICODE_SUPPORT  is
              available, the option -U forces unzip to escape all non-ASCII characters from UTF-8
              coded filenames as ``#Uxxxx'' (for UCS-2 characters, or  ``#Lxxxxxx''  for  unicode
              codepoints needing 3 octets).  This option is mainly provided for debugging purpose
              when the fairly new UTF-8 support is suspected to mangle up extracted filenames.

              The option -UU  allows  to  entirely  disable  the  recognition  of  UTF-8  encoded
              filenames.   The  handling  of  filename  codings  within  unzip  falls back to the
              behaviour of previous versions.

              [old, obsolete usage] leave filenames uppercase if created under MS-DOS, VMS,  etc.
              See -L above.

       -V     retain  (VMS) file version numbers.  VMS files can be stored with a version number,
              in the format file.ext;##.  By default the ``;##'' version  numbers  are  stripped,
              but  this option allows them to be retained.  (On file systems that limit filenames
              to particularly short lengths, the version numbers may  be  truncated  or  stripped
              regardless of this option.)

       -W     [only  when  WILD_STOP_AT_DIR  compile-time  option  enabled]  modifies the pattern
              matching routine so that  both  `?'  (single-char  wildcard)  and  `*'  (multi-char
              wildcard)  do  not match the directory separator character `/'.  (The two-character
              sequence ``**'' acts as a multi-char wildcard that includes the directory separator
              in its matched characters.)  Examples:

           "*.c" matches "foo.c" but not "mydir/foo.c"
           "**.c" matches both "foo.c" and "mydir/foo.c"
           "*/*.c" matches "bar/foo.c" but not "baz/bar/foo.c"
           "??*/*" matches "ab/foo" and "abc/foo"
                   but not "a/foo" or "a/b/foo"

              This  modified  behaviour  is  equivalent to the pattern matching style used by the
              shells of some of UnZip's supported target OSs (one  example  is  Acorn  RISC  OS).
              This  option  may  not  be  available  on  systems where the Zip archive's internal
              directory separator character  `/'  is  allowed  as  regular  character  in  native
              operating system filenames.  (Currently, UnZip uses the same pattern matching rules
              for both wildcard zipfile specifications and zip entry selection patterns  in  most
              ports.  For systems allowing `/' as regular filename character, the -W option would
              not work as expected on a wildcard zipfile specification.)

       -X     [VMS, Unix, OS/2, NT, Tandem] restore owner/protection info (UICs and ACL  entries)
              under  VMS,  or  user  and group info (UID/GID) under Unix, or access control lists
              (ACLs) under certain network-enabled versions of OS/2 (Warp  Server  with  IBM  LAN
              Server/Requester  3.0  to  5.0;  Warp  Connect with IBM Peer 1.0), or security ACLs
              under Windows NT.  In most cases this will require special system  privileges,  and
              doubling  the  option  (-XX)  under  NT  instructs  unzip  to  use  privileges  for
              extraction; but under Unix, for example, a user who belongs to several  groups  can
              restore  files  owned  by any of those groups, as long as the user IDs match his or
              her own.  Note that ordinary  file  attributes  are  always  restored--this  option
              applies only to optional, extra ownership info available on some operating systems.
              [NT's access control lists do not appear to be especially compatible  with  OS/2's,
              so  no  attempt  is made at cross-platform portability of access privileges.  It is
              not clear under what conditions this would ever be useful anyway.]

       -Y     [VMS] treat archived file name endings of ``.nnn''  (where  ``nnn''  is  a  decimal
              number)  as  if they were VMS version numbers (``;nnn'').  (The default is to treat
              them as file types.)  Example:
                   "a.b.3" -> "a.b;3".

       -$     [MS-DOS, OS/2, NT] restore the volume label if the extraction medium  is  removable
              (e.g.,  a  diskette).  Doubling the option (-$$) allows fixed media (hard disks) to
              be labelled as well.  By default, volume labels are ignored.

       -/ extensions
              [Acorn only]  overrides  the  extension  list  supplied  by  Unzip$Ext  environment
              variable.  During  extraction,  filename  extensions that match one of the items in
              this extension list are swapped in front of the base name of the extracted file.

       -:     [all but Acorn, VM/CMS,  MVS,  Tandem]  allows  to  extract  archive  members  into
              locations outside of the current `` extraction root folder''. For security reasons,
              unzip normally removes ``parent dir'' path components (``../'') from the  names  of
              extracted  file.   This  safety  feature (new for version 5.50) prevents unzip from
              accidentally writing files to ``sensitive'' areas  outside  the  active  extraction
              folder  tree  head.   The  -:  option  lets unzip switch back to its previous, more
              liberal behaviour, to allow exact extraction of (older) archives that used  ``../''
              components  to  create  multiple  directory  trees  at  the  level  of  the current
              extraction folder.  This option does not enable  writing  explicitly  to  the  root
              directory  (``/'').   To achieve this, it is necessary to set the extraction target
              folder to root (e.g. -d / ).  However, when the -: option is specified, it is still
              possible  to  implicitly  write  to the root directory by specifying enough ``../''
              path components within the zip archive.  Use this option with extreme caution.

       -^     [Unix only] allow control characters in names of extracted ZIP archive entries.  On
              Unix, a file name may contain any (8-bit) character code with the two exception '/'
              (directory delimiter) and NUL (0x00, the C string  termination  indicator),  unless
              the  specific file system has more restrictive conventions.  Generally, this allows
              to embed ASCII control characters (or even sophisticated control sequences) in file
              names,  at  least  on  'native'  Unix  file  systems.   However,  it  may be highly
              suspicious to make use of this Unix "feature".  Embedded control characters in file
              names  might  have nasty side effects when displayed on screen by some listing code
              without sufficient filtering.  And, for ordinary users,  it  may  be  difficult  to
              handle  such  file  names  (e.g. when trying to specify it for open, copy, move, or
              delete operations).  Therefore, unzip applies a  filter  by  default  that  removes
              potentially  dangerous  control  characters  from  the extracted file names. The -^
              option allows to override this filter in  the  rare  case  that  embedded  filename
              control characters are to be intentionally restored.

       -2     [VMS] force unconditionally conversion of file names to ODS2-compatible names.  The
              default is to exploit the destination file system,  preserving  case  and  extended
              file  name  characters  on  an  ODS5  destination  file  system;  and  applying the
              ODS2-compatibility file name filtering on an ODS2 destination file system.

ENVIRONMENT OPTIONS

       unzip's default behavior may be modified via options placed in  an  environment  variable.
       This  can be done with any option, but it is probably most useful with the -a, -L, -C, -q,
       -o, or -n modifiers:  make unzip auto-convert text  files  by  default,  make  it  convert
       filenames  from  uppercase  systems  to lowercase, make it match names case-insensitively,
       make it quieter, or make it always overwrite or never overwrite files as it extracts them.
       For  example,  to  make unzip act as quietly as possible, only reporting errors, one would
       use one of the following commands:

         Unix Bourne shell:
              UNZIP=-qq; export UNZIP

         Unix C shell:
              setenv UNZIP -qq

         OS/2 or MS-DOS:
              set UNZIP=-qq

         VMS (quotes for lowercase):
              define UNZIP_OPTS "-qq"

       Environment options are, in effect, considered to be  just  like  any  other  command-line
       options,  except  that  they  are  effectively  the first options on the command line.  To
       override an environment option, one may use the ``minus  operator''  to  remove  it.   For
       instance, to override one of the quiet-flags in the example above, use the command

       unzip --q[other options] zipfile

       The first hyphen is the normal switch character, and the second is a minus sign, acting on
       the q option.  Thus the effect here is to cancel one quantum of quietness.  To cancel both
       quiet flags, two (or more) minuses may be used:

       unzip -t--q zipfile
       unzip ---qt zipfile

       (the  two  are  equivalent).   This  may  seem  awkward or confusing, but it is reasonably
       intuitive:  just ignore the first hyphen and go from there.  It is  also  consistent  with
       the behavior of Unix nice(1).

       As  suggested  by  the  examples  above, the default variable names are UNZIP_OPTS for VMS
       (where the symbol used to install unzip as a foreign command would otherwise  be  confused
       with  the  environment  variable),  and  UNZIP  for  all  other  operating  systems.   For
       compatibility with zip(1), UNZIPOPT is also accepted  (don't  ask).   If  both  UNZIP  and
       UNZIPOPT are defined, however, UNZIP takes precedence.  unzip's diagnostic option (-v with
       no zipfile name) can be used to check the values of all four possible  unzip  and  zipinfo
       environment variables.

       The  timezone variable (TZ) should be set according to the local timezone in order for the
       -f and -u to operate correctly.  See the  description  of  -f  above  for  details.   This
       variable  may  also be necessary to get timestamps of extracted files to be set correctly.
       The WIN32 (Win9x/ME/NT4/2K/XP/2K3) port of unzip gets the timezone configuration from  the
       registry,  assuming  it is correctly set in the Control Panel.  The TZ variable is ignored
       for this port.

DECRYPTION

       Encrypted archives are fully supported by Info-ZIP software,  but  due  to  United  States
       export  restrictions,  de-/encryption  support  might be disabled in your compiled binary.
       However, since spring 2000, US export restrictions have been  liberated,  and  our  source
       archives do now include full crypt code.  In case you need binary distributions with crypt
       support enabled, see the file ``WHERE'' in any Info-ZIP source or binary distribution  for
       locations both inside and outside the US.

       Some  compiled versions of unzip may not support decryption.  To check a version for crypt
       support, either attempt to test or extract an encrypted archive,  or  else  check  unzip's
       diagnostic  screen  (see  the  -v option above) for ``[decryption]'' as one of the special
       compilation options.

       As noted above, the -P option may be used to supply a password on the command line, but at
       a  cost  in security.  The preferred decryption method is simply to extract normally; if a
       zipfile member is encrypted, unzip will prompt for the password without  echoing  what  is
       typed.   unzip  continues  to  use the same password as long as it appears to be valid, by
       testing a 12-byte header on each file.  The correct password will always check out against
       the header, but there is a 1-in-256 chance that an incorrect password will as well.  (This
       is a security feature of the PKWARE zipfile format; it helps prevent  brute-force  attacks
       that  might  otherwise  gain  a large speed advantage by testing only the header.)  In the
       case that an incorrect password is given but it passes the header test anyway,  either  an
       incorrect  CRC will be generated for the extracted data or else unzip will fail during the
       extraction because the ``decrypted'' bytes do  not  constitute  a  valid  compressed  data
       stream.

       If  the  first password fails the header check on some file, unzip will prompt for another
       password, and so on until all files are extracted.  If a password is not known, entering a
       null  password (that is, just a carriage return or ``Enter'') is taken as a signal to skip
       all further prompting.  Only unencrypted  files  in  the  archive(s)  will  thereafter  be
       extracted.   (In  fact,  that's  not  quite true; older versions of zip(1) and zipcloak(1)
       allowed null passwords, so unzip checks each encrypted file to see if  the  null  password
       works.  This may result in ``false positives'' and extraction errors, as noted above.)

       Archives  encrypted  with  8-bit  passwords (for example, passwords with accented European
       characters) may not be portable across systems and/or other archivers.  This problem stems
       from  the  use  of  multiple  encoding methods for such characters, including Latin-1 (ISO
       8859-1) and OEM code page 850.  DOS PKZIP 2.04g uses the OEM code page; Windows PKZIP 2.50
       uses  Latin-1  (and  is therefore incompatible with DOS PKZIP); Info-ZIP uses the OEM code
       page on DOS, OS/2 and Win3.x ports but ISO coding (Latin-1 etc.) everywhere else; and Nico
       Mak's  WinZip 6.x does not allow 8-bit passwords at all.  UnZip 5.3 (or newer) attempts to
       use the default character set first (e.g., Latin-1), followed by the alternate one  (e.g.,
       OEM  code  page)  to  test  passwords.   On  EBCDIC systems, if both of these fail, EBCDIC
       encoding will be tested as a last resort.  (EBCDIC is not tested  on  non-EBCDIC  systems,
       because  there  are no known archivers that encrypt using EBCDIC encoding.)  ISO character
       encodings other than Latin-1 are not supported.  The new addition of  (partially)  Unicode
       (resp.   UTF-8)  support  in UnZip 6.0 has not yet been adapted to the encryption password
       handling in unzip.  On systems that use UTF-8 as native character encoding,  unzip  simply
       tries  decryption  with  the native UTF-8 encoded password; the built-in attempts to check
       the password in translated encoding have not yet been adapted for UTF-8 support  and  will
       consequently fail.

EXAMPLES

       To  use unzip to extract all members of the archive letters.zip into the current directory
       and subdirectories below it, creating any subdirectories as necessary:

       unzip letters

       To extract all members of letters.zip into the current directory only:

       unzip -j letters

       To test letters.zip, printing only a summary message indicating whether the archive is  OK
       or not:

       unzip -tq letters

       To test all zipfiles in the current directory, printing only the summaries:

       unzip -tq \*.zip

       (The  backslash before the asterisk is only required if the shell expands wildcards, as in
       Unix; double quotes could have been used instead, as in the  source  examples  below.)  To
       extract  to  standard  output  all  members  of letters.zip whose names end in .tex, auto-
       converting to the local end-of-line convention and piping the output into more(1):

       unzip -ca letters \*.tex | more

       To extract the binary file paper1.dvi to  standard  output  and  pipe  it  to  a  printing
       program:

       unzip -p articles paper1.dvi | dvips

       To  extract  all  FORTRAN  and  C source files--*.f, *.c, *.h, and Makefile--into the /tmp
       directory:

       unzip source.zip "*.[fch]" Makefile -d /tmp

       (the double quotes are necessary only in Unix and only if  globbing  is  turned  on).   To
       extract  all  FORTRAN  and C source files, regardless of case (e.g., both *.c and *.C, and
       any makefile, Makefile, MAKEFILE or similar):

       unzip -C source.zip "*.[fch]" makefile -d /tmp

       To extract any such files but convert any uppercase MS-DOS or VMS names to  lowercase  and
       convert the line-endings of all of the files to the local standard (without respect to any
       files that might be marked ``binary''):

       unzip -aaCL source.zip "*.[fch]" makefile -d /tmp

       To extract only newer versions of the files already  in  the  current  directory,  without
       querying (NOTE:  be careful of unzipping in one timezone a zipfile created in another--ZIP
       archives other than those created by Zip 2.1 or later contain no timezone information, and
       a ``newer'' file from an eastern timezone may, in fact, be older):

       unzip -fo sources

       To  extract newer versions of the files already in the current directory and to create any
       files not already there (same caveat as previous example):

       unzip -uo sources

       To display a diagnostic screen showing which unzip  and  zipinfo  options  are  stored  in
       environment variables, whether decryption support was compiled in, the compiler with which
       unzip was compiled, etc.:

       unzip -v

       In the last five examples, assume that UNZIP or UNZIP_OPTS is set to -q.  To do  a  singly
       quiet listing:

       unzip -l file.zip

       To do a doubly quiet listing:

       unzip -ql file.zip

       (Note that the ``.zip'' is generally not necessary.)  To do a standard listing:

       unzip --ql file.zip
       or
       unzip -l-q file.zip
       or
       unzip -l--q file.zip
       (Extra minuses in options don't hurt.)

TIPS

       The  current  maintainer,  being  a  lazy  sort,  finds it very useful to define a pair of
       aliases:  tt for ``unzip -tq'' and ii for ``unzip -Z'' (or  ``zipinfo'').   One  may  then
       simply  type  ``tt zipfile'' to test an archive, something that is worth making a habit of
       doing.   With  luck  unzip  will  report  ``No  errors  detected  in  compressed  data  of
       zipfile.zip,'' after which one may breathe a sigh of relief.

       The  maintainer  also finds it useful to set the UNZIP environment variable to ``-aL'' and
       is tempted to add ``-C'' as well.  His ZIPINFO variable is set to ``-z''.

DIAGNOSTICS

       The exit status (or error level) approximates the exit codes defined by PKWARE  and  takes
       on the following values, except under VMS:

              0      normal; no errors or warnings detected.

              1      one  or  more  warning  errors  were  encountered,  but processing completed
                     successfully anyway.  This includes zipfiles where one  or  more  files  was
                     skipped  due to unsupported compression method or encryption with an unknown
                     password.

              2      a generic error in the zipfile format was  detected.   Processing  may  have
                     completed  successfully  anyway;  some  broken  zipfiles  created  by  other
                     archivers have simple work-arounds.

              3      a severe error in the zipfile  format  was  detected.   Processing  probably
                     failed immediately.

              4      unzip  was  unable to allocate memory for one or more buffers during program
                     initialization.

              5      unzip was unable to allocate memory or unable to obtain a tty  to  read  the
                     decryption password(s).

              6      unzip was unable to allocate memory during decompression to disk.

              7      unzip was unable to allocate memory during in-memory decompression.

              8      [currently not used]

              9      the specified zipfiles were not found.

              10     invalid options were specified on the command line.

              11     no matching files were found.

              50     the disk is (or was) full during extraction.

              51     the end of the ZIP archive was encountered prematurely.

              80     the user aborted unzip prematurely with control-C (or similar)

              81     testing  or  extraction  of  one  or  more  files  failed due to unsupported
                     compression methods or unsupported decryption.

              82     no files were found due to bad decryption password(s).  (If even one file is
                     successfully processed, however, the exit status is 1.)

       VMS  interprets  standard  Unix (or PC) return values as other, scarier-looking things, so
       unzip instead maps them into VMS-style status codes.  The current mapping is  as  follows:
       1   (success)   for  normal  exit,  0x7fff0001  for  warning  errors,  and  (0x7fff000?  +
       16*normal_unzip_exit_status) for all other errors, where the `?' is 2  (error)  for  unzip
       values  2,  9-11  and 80-82, and 4 (fatal error) for the remaining ones (3-8, 50, 51).  In
       addition,  there  is  a  compilation  option  to  expand  upon  this  behavior:   defining
       RETURN_CODES results in a human-readable explanation of what the error status means.

BUGS

       Multi-part  archives  are  not  yet supported, except in conjunction with zip.  (All parts
       must be concatenated together in order, and then ``zip -F'' (for zip 2.x) or  ``zip  -FF''
       (for zip 3.x) must be performed on the concatenated archive in order to ``fix'' it.  Also,
       zip 3.0 and later can combine multi-part (split)  archives  into  a  combined  single-file
       archive  using  ``zip  -s-  inarchive -O outarchive''.  See the zip 3 manual page for more
       information.)  This will definitely be corrected in the next major release.

       Archives read from standard input are not yet supported, except with funzip (and then only
       the first member of the archive can be extracted).

       Archives   encrypted   with  8-bit  passwords  (e.g.,  passwords  with  accented  European
       characters) may not be portable across systems and/or other archivers.  See the discussion
       in DECRYPTION above.

       unzip's  -M (``more'') option tries to take into account automatic wrapping of long lines.
       However, the code may fail to detect the correct wrapping locations. First, TAB characters
       (and  similar  control sequences) are not taken into account, they are handled as ordinary
       printable characters.  Second, depending on the actual system / OS  port,  unzip  may  not
       detect  the  true  screen  geometry but rather rely on "commonly used" default dimensions.
       The correct handling of tabs would require the implementation of a query  for  the  actual
       tabulator setup on the output console.

       Dates, times and permissions of stored directories are not restored except under Unix. (On
       Windows NT and successors, timestamps are now restored.)

       [MS-DOS] When extracting or testing files from an archive on a defective floppy  diskette,
       if  the  ``Fail''  option  is  chosen  from  DOS's  ``Abort, Retry, Fail?'' message, older
       versions of unzip may hang the system, requiring a reboot.  This  problem  appears  to  be
       fixed, but control-C (or control-Break) can still be used to terminate unzip.

       Under  DEC  Ultrix,  unzip  would  sometimes  fail  on  long zipfiles (bad CRC, not always
       reproducible).  This was apparently due either to a hardware  bug  (cache  memory)  or  an
       operating system bug (improper handling of page faults?).  Since Ultrix has been abandoned
       in favor of Digital Unix (OSF/1), this may not be an issue anymore.

       [Unix] Unix special files such as FIFO buffers (named pipes), block devices and  character
       devices  are  not  restored  even  if they are somehow represented in the zipfile, nor are
       hard-linked files relinked.  Basically the only file types restored by unzip  are  regular
       files, directories and symbolic (soft) links.

       [OS/2]   Extended  attributes  for  existing  directories  are  only  updated  if  the  -o
       (``overwrite all'') option is given.  This  is  a  limitation  of  the  operating  system;
       because  directories  only  have a creation time associated with them, unzip has no way to
       determine whether the stored attributes are  newer  or  older  than  those  on  disk.   In
       practice this may mean a two-pass approach is required:  first unpack the archive normally
       (with or without freshening/updating existing files), then overwrite  just  the  directory
       entries (e.g., ``unzip -o foo */'').

       [VMS]  When extracting to another directory, only the [.foo] syntax is accepted for the -d
       option; the simple Unix foo syntax is silently ignored (as is the less common VMS  foo.dir
       syntax).

       [VMS]  When  the  file being extracted already exists, unzip's query only allows skipping,
       overwriting or renaming; there should additionally be a choice for creating a new  version
       of the file.  In fact, the ``overwrite'' choice does create a new version; the old version
       is not overwritten or deleted.

SEE ALSO

       funzip(1), zip(1), zipcloak(1), zipgrep(1), zipinfo(1), zipnote(1), zipsplit(1)

URL

       The Info-ZIP home page is currently at
       http://www.info-zip.org/pub/infozip/
       or
       ftp://ftp.info-zip.org/pub/infozip/ .

AUTHORS

       The primary Info-ZIP authors (current semi-active members of the Zip-Bugs workgroup)  are:
       Ed  Gordon (Zip, general maintenance, shared code, Zip64, Win32, Unix, Unicode); Christian
       Spieler (UnZip maintenance coordination, VMS, MS-DOS, Win32, shared code, general Zip  and
       UnZip integration and optimization); Onno van der Linden (Zip); Mike White (Win32, Windows
       GUI, Windows DLLs); Kai Uwe Rommel (OS/2, Win32); Steven M. Schweda (VMS, Unix, support of
       new  features);  Paul  Kienitz (Amiga, Win32, Unicode); Chris Herborth (BeOS, QNX, Atari);
       Jonathan Hudson (SMS/QDOS); Sergio Monesi (Acorn RISC OS);  Harald  Denker  (Atari,  MVS);
       John  Bush  (Solaris,  Amiga);  Hunter  Goatley  (VMS,  Info-ZIP  Site maintenance); Steve
       Salisbury (Win32); Steve Miller (Windows CE GUI), Johnny Lee (MS-DOS, Win32,  Zip64);  and
       Dave Smith (Tandem NSK).

       The  following  people  were former members of the Info-ZIP development group and provided
       major contributions to key parts of the current code: Greg ``Cave Newt''  Roelofs  (UnZip,
       unshrink  decompression);  Jean-loup  Gailly  (deflate  compression);  Mark Adler (inflate
       decompression, fUnZip).

       The author of the original unzip code upon which Info-ZIP's was based is Samuel H.  Smith;
       Carl  Mascott did the first Unix port; and David P.  Kirschbaum organized and led Info-ZIP
       in its early days with Keith Petersen hosting the original mailing list at  WSMR-SimTel20.
       The full list of contributors to UnZip has grown quite large; please refer to the CONTRIBS
       file in the UnZip source distribution for a relatively complete version.

VERSIONS

       v1.2   15 Mar 89   Samuel H. Smith
       v2.0    9 Sep 89   Samuel H. Smith
       v2.x   fall 1989   many Usenet contributors
       v3.0    1 May 90   Info-ZIP (DPK, consolidator)
       v3.1   15 Aug 90   Info-ZIP (DPK, consolidator)
       v4.0    1 Dec 90   Info-ZIP (GRR, maintainer)
       v4.1   12 May 91   Info-ZIP
       v4.2   20 Mar 92   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.0   21 Aug 92   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.01  15 Jan 93   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.1    7 Feb 94   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.11   2 Aug 94   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.12  28 Aug 94   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.2   30 Apr 96   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.3   22 Apr 97   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.31  31 May 97   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.32   3 Nov 97   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.4   28 Nov 98   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.41  16 Apr 00   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.42  14 Jan 01   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.5   17 Feb 02   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.51  22 May 04   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.52  28 Feb 05   Info-ZIP (Zip-Bugs subgroup, SPC)
       v6.0   20 Apr 09   Info-ZIP (Zip-Bugs subgroup, SPC)