Provided by: unzip_5.52-10ubuntu2_i386 bug

NAME

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

SYNOPSIS

       unzip  [-Z]  [-cflptTuvz[abjnoqsCKLMVWX$/:]]  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     be  verbose  or  print 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.

       -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     [Unix only, and only if compiled with UNIXBACKUP defined] save a
              backup  copy  of  each  overwritten  file  with a tilde appended
              (e.g., the old copy of ‘‘foo’’ is renamed to ‘‘foo~’’).  This is
              similar to the default behavior of emacs(1) in many locations.

       -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 -L 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’’!

       -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.

       -U     (obsolete;  to  be  removed in a future release) 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] restore owner/protection info (UICs) 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.]

       -$     [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.

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  Latin-1
       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.

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’’ must be performed on the concatenated archive in order to  ‘‘fix’’
       it.)  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); 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,  support  of  new  features);  Paul Kienitz (Amiga, Win32); 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)