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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13 uncompress — expand compressed data
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16 uncompress [−cfv] [file...]
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19 The uncompress utility shall restore files to their original state
20 after they have been compressed using the compress utility. If no files
21 are specified, the standard input shall be uncompressed to the standard
22 output. If the invoking process has appropriate privileges, the owner‐
23 ship, modes, access time, and modification time of the original file
24 shall be preserved.
25 This utility shall support the uncompressing of any files produced by
27 the compress utility on the same implementation. For files produced by
28 compress on other systems, uncompress supports 9 to 14-bit compression
29 (see compress, −b); it is implementation-defined whether values of −b
30 greater than 14 are supported.
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33 The uncompress utility shall conform to the Base Definitions volume of
34 POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines, except that
35 Guideline 1 does apply since the utility name has ten letters.
36 The following options shall be supported:
38 −c Write to standard output; no files are changed.
40 −f Do not prompt for overwriting files. Except when run in the
42 background, if −f is not given the user shall be prompted as
43 to whether an existing file should be overwritten. If the
44 standard input is not a terminal and −f is not given, uncom‐
45 press shall write a diagnostic message to standard error and
46 exit with a status greater than zero.
47 −v Write messages to standard error concerning the expansion of
49 each file.
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52 The following operand shall be supported:
53 file A pathname of a file. If file already has the .Z suffix spec‐
55 ified, it shall be used as the input file and the output file
56 shall be named file with the .Z suffix removed. Otherwise,
57 file shall be used as the name of the output file and file
58 with the .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 vari‐
72 ables that are unset or null. (See the Base Definitions vol‐
73 ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
74 ables for the precedence of internationalization variables
75 used to determine the values of locale categories.)
76 LC_ALL If set to a non-empty string value, override the values of
78 all the other internationalization variables.
79 LC_CTYPE Determine the locale for the interpretation of sequences of
81 bytes of text data as characters (for example, single-byte as
82 opposed to multi-byte characters in arguments).
83 LC_MESSAGES
85 Determine the locale that should be used to affect the format
86 and contents of diagnostic messages written to standard
87 error.
88 NLSPATH Determine the location of message catalogs for the processing
90 of LC_MESSAGES.
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93 Default.
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96 When there are no file operands or the −c option is specified, the
97 uncompressed output is written to standard output.
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100 Prompts shall be written to the standard error output under the condi‐
101 tions specified in the DESCRIPTION and OPTIONS sections. The prompts
102 shall contain the file pathname, but their format is otherwise unspeci‐
103 fied. Otherwise, the standard error output shall be used only for diag‐
104 nostic messages.
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107 Output files are the same as the respective input files to compress.
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110 None.
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113 The following exit values shall be returned:
114 0 Successful completion.
116 >0 An error occurred.
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120 The input file remains unmodified.
121 The following sections are informative.
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125 The limit of 14 on the compress −b bits argument is to achieve porta‐
126 bility to all systems (within the restrictions imposed by the lack of
127 an explicit published file format). Some implementations based on
128 16-bit architectures cannot support 15 or 16-bit uncompression.
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131 None.
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134 None.
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137 None.
138
140 compress, zcat
141 The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
143 Variables, Section 12.2, Utility Syntax Guidelines
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146 Portions of this text are reprinted and reproduced in electronic form
147 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
148 -- Portable Operating System Interface (POSIX), The Open Group Base
149 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
150 cal and Electronics Engineers, Inc and The Open Group. (This is
151 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
152 event of any discrepancy between this version and the original IEEE and
153 The Open Group Standard, the original IEEE and The Open Group Standard
154 is the referee document. The original Standard can be obtained online
155 at http://www.unix.org/online.html .
156 Any typographical or formatting errors that appear in this page are
158 most likely to have been introduced during the conversion of the source
159 files to man page format. To report such errors, see https://www.ker‐
160 nel.org/doc/man-pages/reporting_bugs.html .
161IEEE/The Open Group 2013 UNCOMPRESS(1P)