UNCOMPRESS
Section: POSIX Programmer's Manual (P)
Updated: 2003
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 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 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 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 Variables
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 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 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 .
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- OPERANDS
-
- STDIN
-
- INPUT FILES
-
- ENVIRONMENT VARIABLES
-
- ASYNCHRONOUS EVENTS
-
- STDOUT
-
- STDERR
-
- OUTPUT FILES
-
- EXTENDED DESCRIPTION
-
- EXIT STATUS
-
- CONSEQUENCES OF ERRORS
-
- APPLICATION USAGE
-
- EXAMPLES
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-
This document was created by
man2html,
using the manual pages.
Time: 07:35:55 GMT, March 26, 2013