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unzip




SYNOPSIS

       unzip   [-Z]   [-cflptuvz[abjnoqsCLMOVX$/:]]    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(1L), cre­
       ates 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 specifica­
              tion 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).

              (Be  sure  to quote any character that might other­
              wise 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 pro­
              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 recre­
              ated in the current directory; the -d option allows
              extraction in an arbitrary directory (always assum­
              ing one has permission to write to the  directory).
              This  option need not appear at the end of the com­
              mand line; it is also accepted before  the  zipfile
              specification  (with  the  normal options), immedi­
              ately 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 partic­
              ular, ``-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(1L) mode.  If the first option on the  com­
              mand line is -Z, the remaining options are taken to
              be zipinfo(1L) 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 conver­
              sion 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
              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 indi­
              vidual  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 corre­
              sponds 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 informa­
              tion 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.
              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  operat­
              ing  system  for  which it was compiled, as well as
              (possibly) the hardware on which it  was  compiled,
              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 zip­
              info 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  per­
              fect;  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, regard­
              less of the supposed file type.

       -b     [general] treat all files as binary (no  text  con­
              versions).  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  loca­
              tions.

       -C     match  filenames  case-insensitively.  unzip's phi­
              losophy is ``you get what you ask  for''  (this  is
              also responsible for the -L/-U change; see the rel­
              evant 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 plat­
              excluded-file list (xlist).

       -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  infor­
              mation 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 Macin­
              tosh   specific  info  is  skipped.  Data-fork  and
              resource-fork are restored as separate files.

       -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 identi­
              cal 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  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 avail­
              able  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(1L), or with the -N option of the Amiga port of
              zip(1L), 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.)

       -O     +file  names will be converted to ISO8859-2 instead
              of to ISO8859-1

       -P password
              use password to decrypt encrypted  zipfile  entries
              (if any).  THIS IS INSECURE!  Many multi-user oper­
              ating 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.

       -V     retain (VMS) file version numbers.  VMS  files  can
              be  stored  with  a  version  number, in the format
              file.ext;##.  By default the ``;##''  version  num­
              bers  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.)

       -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  extrac­
              tion,  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 secu­
              rity reasons, unzip normally removes ``parent dir''
              path   components   (``../'')  from  the  names  of
              extracted file.  This safety feature (new for  ver­
              sion 5.50) prevents unzip from accidentally writing
              files to ``sensitive''  areas  outside  the  active

       insensitively, make it quieter, or make  it  always  over­
       write  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 com­
       mands:

         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 con­
       fusing, 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 con­
       fused  with  the  environment variable), and UNZIP for all
       other operating systems.  For compatibility with  zip(1L),
       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.

       tions have been liberated, and our source archives do  now
       include  full crypt code.  In case you need binary distri­
       butions with crypt support enabled, see the file ``WHERE''
       in  any  Info-ZIP  source or binary distribution for loca­
       tions both inside and outside the US.

       Some compiled versions of unzip may  not  support  decryp­
       tion.   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 nor­
       mally; 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 incor­
       rect password is given but it passes the header test  any­
       way,  either  an  incorrect  CRC will be generated for the
       extracted data or else unzip will fail during the  extrac­
       tion  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(1L) and zipcloak(1L) allowed null
       passwords, so unzip checks each encrypted file to  see  if
       the null password works.  This may result in ``false posi­
       tives'' 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
       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 indi­
       cating 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 let­
       ters.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
           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 envi­
       ronment 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  any­
                     way.   This  includes  zipfiles where one or

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

              5      unzip  was  unable  to  allocate  memory  or
                     unable  to  obtain a tty to read the decryp­
                     tion 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  com­
                     mand 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 con­
                     trol-C (or similar)

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

              82     no files were found due  to  bad  decryption
                     password(s).   (If even one file is success­
                     fully 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*nor­
       mal_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.

       in DECRYPTION above.

       unzip's -M (``more'') option is overly simplistic  in  its
       handling  of  screen  output;  as noted above, it fails to
       detect the wrapping of long lines and  may  thereby  cause
       lines  at  the top of the screen to be scrolled off before
       being read.  unzip should detect and treat each occurrence
       of   line-wrap  as  one  additional  line  printed.   This
       requires knowledge of the screen's width as  well  as  its
       height.   In addition, unzip should detect the true screen
       geometry on all systems.

       Dates, times and permissions of stored directories are not
       restored except under Unix.

       [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 con­
       trol-Break) can still be used to terminate unzip.

       Under DEC Ultrix, unzip would sometimes fail on long  zip­
       files (bad CRC, not always reproducible).  This was appar­
       ently 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 zip­
       file, 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 fresh­
       ening/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).

       or
           ftp://ftp.info-zip.org/pub/infozip/ .


AUTHORS

       The primary Info-ZIP authors (current semi-active  members
       of  the  Zip-Bugs  workgroup)  are:   Greg  ``Cave  Newt''
       Roelofs (UnZip); Onno  van  der  Linden  (Zip);  Jean-loup
       Gailly  (compression); Mark Adler (decompression, fUnZip);
       Christian Spieler (UnZip maintance coordination, VMS,  MS-
       DOS,  Windows  95,  NT, shared code, general Zip and UnZip
       integration and optimization); Mike  White  (Windows  GUI,
       Windows DLLs); Kai Uwe Rommel (OS/2); Paul Kienitz (Amiga,
       Windows 95); 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);  Steve  Salisbury  (Windows 95, NT); Steve
       Miller (Windows CE GUI), Johnny Lee (MS-DOS,  Windows  95,
       NT); and Dave Smith (Tandem NSK).  The author of the orig­
       inal 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)

  




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