1UNCOMPRESS(1P) POSIX Programmer's Manual UNCOMPRESS(1P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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12 uncompress - expand compressed data
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15 uncompress [-cfv][file...]
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18 The uncompress utility shall restore files to their original state
19 after they have been compressed using the compress utility. If no
20 files are specified, the standard input shall be uncompressed to the
21 standard output. If the invoking process has appropriate privileges,
22 the ownership, modes, access time, and modification time of the origi‐
23 nal file shall be preserved.
24 This utility shall support the uncompressing of any files produced by
26 the compress utility on the same implementation. For files produced by
27 compress on other systems, uncompress supports 9 to 14-bit compression
28 (see compress, -b); it is implementation-defined whether values of -b
29 greater than 14 are supported.
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32 The uncompress utility shall conform to the Base Definitions volume of
33 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
34 The following options shall be supported:
36 -c Write to standard output; no files are changed.
38 -f Do not prompt for overwriting files. Except when run in the
40 background, if -f is not given the user shall be prompted as to
41 whether an existing file should be overwritten. If the standard
42 input is not a terminal and -f is not given, uncompress shall
43 write a diagnostic message to standard error and exit with a
44 status greater than zero.
45 -v Write messages to standard error concerning the expansion of
47 each file.
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51 The following operand shall be supported:
52 file A pathname of a file. If file already has the .Z suffix speci‐
54 fied, it shall be used as the input file and the output file
55 shall be named file with the .Z suffix removed. Otherwise, file
56 shall be used as the name of the output file and file with the
57 .Z suffix appended shall be used as the input file.
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61 The standard input shall be used only if no file operands are speci‐
62 fied, or if a file operand is '-' .
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65 Input files shall be in the format produced by the compress utility.
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68 The following environment variables shall affect the execution of
69 uncompress:
70 LANG Provide a default value for the internationalization variables
72 that are unset or null. (See the Base Definitions volume of
73 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
74 ables for the precedence of internationalization variables used
75 to determine the values of locale categories.)
76 LC_ALL If set to a non-empty string value, override the values of all
78 the other internationalization variables.
79 LC_CTYPE
81 Determine the locale for the interpretation of sequences of
82 bytes of text data as characters (for example, single-byte as
83 opposed to multi-byte characters in arguments).
84 LC_MESSAGES
86 Determine the locale that should be used to affect the format
87 and contents of diagnostic messages written to standard error.
88 NLSPATH
90 Determine the location of message catalogs for the processing of
91 LC_MESSAGES .
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95 Default.
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98 When there are no file operands or the -c option is specified, the
99 uncompressed output is written to standard output.
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102 Prompts shall be written to the standard error output under the condi‐
103 tions specified in the DESCRIPTION and OPTIONS sections. The prompts
104 shall contain the file pathname, but their format is otherwise unspeci‐
105 fied. Otherwise, the standard error output shall be used only for diag‐
106 nostic messages.
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109 Output files are the same as the respective input files to compress.
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112 None.
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115 The following exit values shall be returned:
116 0 Successful completion.
118 >0 An error occurred.
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123 The input file remains unmodified.
124 The following sections are informative.
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128 The limit of 14 on the compress -b bits argument is to achieve porta‐
129 bility to all systems (within the restrictions imposed by the lack of
130 an explicit published file format). Some implementations based on
131 16-bit architectures cannot support 15 or 16-bit uncompression.
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134 None.
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137 None.
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140 None.
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143 compress, zcat
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146 Portions of this text are reprinted and reproduced in electronic form
147 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
148 -- Portable Operating System Interface (POSIX), The Open Group Base
149 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
150 Electrical and Electronics Engineers, Inc and The Open Group. In the
151 event of any discrepancy between this version and the original IEEE and
152 The Open Group Standard, the original IEEE and The Open Group Standard
153 is the referee document. The original Standard can be obtained online
154 at http://www.opengroup.org/unix/online.html .
155IEEE/The Open Group 2003 UNCOMPRESS(1P)