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.
NAMEuncompress — expand compressed data
SYNOPSISuncompress [−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 owner‐
ship, 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 Definitions volume of
POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines, except that
Guideline 1 does apply since the utility name has ten letters.
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, uncom‐
press 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 spec‐
ified, 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 vari‐
ables that are unset or null. (See the Base Definitions vol‐
ume of POSIX.1‐2008, 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
The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
Variables, Section 12.2, Utility Syntax Guidelines
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 UNCOMPRESS(1P)
