1UNCOMPRESS(1P) POSIX Programmer's Manual UNCOMPRESS(1P)
2
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.
10
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 files
20 are specified, the standard input shall be uncompressed to the standard
21 output. If the invoking process has appropriate privileges, the owner‐
22 ship, modes, access time, and modification time of the original file
23 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 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines, except that
34 Guideline 1 does apply since the utility name has ten letters.
35 The following options shall be supported:
37 -c Write to standard output; no files are changed.
39 -f Do not prompt for overwriting files. Except when run in the
41 background, if -f is not given the user shall be prompted as
42 to whether an existing file should be overwritten. If the
43 standard input is not a terminal and -f is not given, uncom‐
44 press shall write a diagnostic message to standard error and
45 exit with a status greater than zero.
46 -v Write messages to standard error concerning the expansion of
48 each file.
49
51 The following operand shall be supported:
52 file A pathname of a file. If file already has the .Z suffix spec‐
54 ified, it shall be used as the input file and the output file
55 shall be named file with the .Z suffix removed. Otherwise,
56 file shall be used as the name of the output file and file
57 with the .Z suffix appended shall be used as the input file.
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60 The standard input shall be used only if no file operands are speci‐
61 fied, or if a file operand is '-'.
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64 Input files shall be in the format produced by the compress utility.
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67 The following environment variables shall affect the execution of
68 uncompress:
69 LANG Provide a default value for the internationalization vari‐
71 ables that are unset or null. (See the Base Definitions vol‐
72 ume of POSIX.1‐2017, Section 8.2, Internationalization Vari‐
73 ables for the precedence of internationalization variables
74 used to determine the values of locale categories.)
75 LC_ALL If set to a non-empty string value, override the values of
77 all the other internationalization variables.
78 LC_CTYPE Determine the locale for the interpretation of sequences of
80 bytes of text data as characters (for example, single-byte as
81 opposed to multi-byte characters in arguments).
82 LC_MESSAGES
84 Determine the locale that should be used to affect the format
85 and contents of diagnostic messages written to standard
86 error.
87 NLSPATH Determine the location of message catalogs for the processing
89 of LC_MESSAGES.
90
92 Default.
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95 When there are no file operands or the -c option is specified, the
96 uncompressed output is written to standard output.
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99 Prompts shall be written to the standard error output under the condi‐
100 tions specified in the DESCRIPTION and OPTIONS sections. The prompts
101 shall contain the file pathname, but their format is otherwise unspeci‐
102 fied. Otherwise, the standard error output shall be used only for diag‐
103 nostic messages.
104
106 Output files are the same as the respective input files to compress.
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109 None.
110
112 The following exit values shall be returned:
113 0 Successful completion.
115 >0 An error occurred.
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119 The input file remains unmodified.
120 The following sections are informative.
122
124 The limit of 14 on the compress -b bits argument is to achieve porta‐
125 bility to all systems (within the restrictions imposed by the lack of
126 an explicit published file format). Some implementations based on
127 16-bit architectures cannot support 15 or 16-bit uncompression.
128
130 None.
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133 None.
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136 None.
137
139 compress, zcat
140 The Base Definitions volume of POSIX.1‐2017, Chapter 8, Environment
142 Variables, Section 12.2, Utility Syntax Guidelines
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145 Portions of this text are reprinted and reproduced in electronic form
146 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
147 table Operating System Interface (POSIX), The Open Group Base Specifi‐
148 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
149 Electrical and Electronics Engineers, Inc and The Open Group. In the
150 event of any discrepancy between this version and the original IEEE and
151 The Open Group Standard, the original IEEE and The Open Group Standard
152 is the referee document. The original Standard can be obtained online
153 at http://www.opengroup.org/unix/online.html .
154 Any typographical or formatting errors that appear in this page are
156 most likely to have been introduced during the conversion of the source
157 files to man page format. To report such errors, see https://www.ker‐
158 nel.org/doc/man-pages/reporting_bugs.html .
159IEEE/The Open Group 2017 UNCOMPRESS(1P)