UNCOMPRESS(P)              POSIX Programmer's Manual             UNCOMPRESS(P)



NAME
       uncompress - expand compressed data

SYNOPSIS
       uncompress [-cfv][file...]

DESCRIPTION
       The  uncompress  utility  shall  restore  files to their
       original state after they have been compressed using the
       compress  utility.  If no files are specified, the stan-
       dard input shall be uncompressed to the standard output.
       If  the invoking process has appropriate privileges, the
       ownership, modes, access time, and modification time  of
       the original file shall be preserved.

       This  utility  shall  support  the  uncompressing of any
       files produced by  the  compress  utility  on  the  same
       implementation.  For files produced by compress on other
       systems, uncompress supports  9  to  14-bit  compression
       (see   compress  ,  -b);  it  is  implementation-defined
       whether values of -b greater than 14 are supported.

OPTIONS
       The uncompress utility shall conform to the Base Defini-
       tions  volume  of  IEEE Std 1003.1-2001,  Section  12.2,
       Utility Syntax Guidelines.

       The following options shall be supported:

       -c     Write to standard output; no files are changed.

       -f     Do not prompt for overwriting files. Except  when
              run  in  the  background,  if -f is not given the
              user shall be prompted as to whether an  existing
              file should be overwritten. If the standard input
              is not a terminal and -f is not given, uncompress
              shall  write  a  diagnostic  message  to standard
              error and exit with a status greater than zero.

       -v     Write messages to standard error  concerning  the
              expansion of each file.


OPERANDS
       The following operand shall be supported:

       file   A  pathname of a file. If file already has the .Z
              suffix specified, it shall be used as  the  input
              file and the output file shall be named file with
              the .Z suffix removed.  Otherwise, file shall  be
              used as the name of the output file and file with
              the .Z suffix appended shall be used as the input
              file.


STDIN
       The  standard  input  shall  be  used  only  if  no file
       operands are specified, or if a file operand is '-' .

INPUT FILES
       Input files shall be in the format produced by the  com-
       press utility.

ENVIRONMENT VARIABLES
       The  following  environment  variables  shall affect the
       execution of uncompress:

       LANG   Provide a default value for the internationaliza-
              tion  variables  that are unset or null. (See the
              Base Definitions volume of  IEEE Std 1003.1-2001,
              Section  8.2,  Internationalization Variables for
              the precedence of internationalization  variables
              used  to  determine  the  values  of locale cate-
              gories.)

       LC_ALL If set to a non-empty string value, override  the
              values  of  all  the  other  internationalization
              variables.

       LC_CTYPE
              Determine the locale for  the  interpretation  of
              sequences  of  bytes  of  text data as characters
              (for example, single-byte as  opposed  to  multi-
              byte characters in arguments).

       LC_MESSAGES
              Determine  the  locale  that  should  be  used to
              affect the format and contents of diagnostic mes-
              sages written to standard error.

       NLSPATH
              Determine  the  location  of message catalogs for
              the processing of LC_MESSAGES .


ASYNCHRONOUS EVENTS
       Default.

STDOUT
       When there are no file operands  or  the  -c  option  is
       specified,  the  uncompressed output is written to stan-
       dard output.

STDERR
       Prompts shall be written to the  standard  error  output
       under  the  conditions  specified in the DESCRIPTION and
       OPTIONS sections.  The prompts shall  contain  the  file
       pathname,  but  their  format  is otherwise unspecified.
       Otherwise, the standard error output shall be used  only
       for diagnostic messages.

OUTPUT FILES
       Output  files are the same as the respective input files
       to compress.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

        0     Successful completion.

       >0     An error occurred.


CONSEQUENCES OF ERRORS
       The input file remains unmodified.

       The following sections are informative.

APPLICATION USAGE
       The limit of 14 on the compress -b bits argument  is  to
       achieve  portability to all systems (within the restric-
       tions imposed by the lack of an explicit published  file
       format).    Some   implementations   based   on   16-bit
       architectures cannot support 15 or 16-bit uncompression.

EXAMPLES
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       compress , zcat

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in
       electronic form from  IEEE  Std  1003.1,  2003  Edition,
       Standard  for Information Technology -- Portable Operat-
       ing System Interface (POSIX), The Open Group Base Speci-
       fications Issue 6, Copyright (C) 2001-2003 by the Insti-
       tute of Electrical and Electronics  Engineers,  Inc  and
       The  Open Group. In the event of any discrepancy between
       this version and the original IEEE and  The  Open  Group
       Standard,  the original IEEE and The Open Group Standard
       is the referee document. The original  Standard  can  be
       obtained        online        at        http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                  2003                        UNCOMPRESS(P)
