zcat - expand and concatenate data
The zcat utility shall write to standard output the uncompressed form
of files that have been compressed using the compress utility. It is
the equivalent of uncompress -c. Input files are not affected.
The following operand shall be supported:
file The pathname of a file previously processed by the compress
utility. If file already has the .Z suffix specified, it is used
as submitted. Otherwise, the .Z suffix is appended to the
filename prior to processing.
The standard input shall be used only if no file operands are
specified, or if a file operand is '-' .
Input files shall be compressed files that are in the format produced
by the compress utility.
The following environment variables shall affect the execution of zcat:
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.
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).
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard error.
Determine the location of message catalogs for the processing of
The compressed files given as input shall be written on standard output
in their uncompressed form.
The standard error shall be used only for diagnostic messages.
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
The following sections are informative.
compress , uncompress
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.php .