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UNCOMPRESS(1P)             POSIX Programmer's Manual            UNCOMPRESS(1P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
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 standard 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  origi-
       nal 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 Definitions 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  speci-
              fied,  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  speci-
       fied, or if a file operand is '-' .
INPUT FILES
       Input files shall be in the format produced by the compress utility.
ENVIRONMENT VARIABLES
       The  following  environment  variables  shall  affect  the execution of
       uncompress:
       LANG   Provide a default value for the  internationalization  variables
              that  are  unset  or  null.  (See the Base Definitions volume of
              IEEE Std 1003.1-2001, Section  8.2,  Internationalization  Vari-
              ables  for the precedence of internationalization variables used
              to determine the values of locale categories.)
       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 messages 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 standard output.
STDERR
       Prompts shall be written to the standard error output under the  condi-
       tions  specified  in the DESCRIPTION and OPTIONS sections.  The prompts
       shall contain the file pathname, but their format is otherwise unspeci-
       fied. Otherwise, the standard error output shall be used only for diag-
       nostic 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  porta-
       bility  to  all systems (within the restrictions 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  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  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.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                       UNCOMPRESS(1P)