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     11 <center><font size="2">
     12 The Open Group Base Specifications Issue 8<br>
     13 IEEE Std 1003.1-2024<br>
     14 Copyright &copy; 2001-2024 The IEEE and The Open Group</font></center>
     15 <hr size="2" noshade>
     16 <a name="top"></a>
     17 
     18 <a name="compress"></a>
     19 <a name = "tag_20_23"></a><!-- compress -->
     20 
     21 
     22 
     23 <h4 class="mansect"><a name = "tag_20_23_01"></a>NAME</h4><blockquote>
     24 compress, uncompress, zcat &mdash; compress and decompress data
     25 
     26 
     27 
     28 
     29 
     30 
     31 </blockquote><h4 class="mansect"><a name = "tag_20_23_02"></a>SYNOPSIS</h4><blockquote class="synopsis">
     32 <p>
     33 <p>
     34 <tt><div class="box"><code><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup>
     35 <img src="../images/opt-start.gif" alt="[Option Start]" border=0>
     36 compress </tt><b>[</b><tt>-fv</tt><b>] [</b><tt>-b </tt><i>value</i><b>] [</b><tt>-g | -m </tt><i>algo</i><b>] [</b><i>file</i><tt>...</tt><b>]</b><tt>
     37 <br>
     38 <br>
     39 compress -c </tt><b>[</b><tt>-fv</tt><b>] [</b><tt>-b </tt><i>value</i><b>] [</b><tt>-g | -m </tt><i>algo</i><b>] [</b><i>file</i><b>]</b><tt>
     40 <br>
     41 <br>
     42 compress -d </tt><b>[</b><tt>-cfv</tt><b>] [</b><i>file</i><tt>...</tt><b>]</b><tt>
     43 <br>
     44 <br>
     45 uncompress </tt><b>[</b><tt>-cfv</tt><b>] [</b><i>file</i><tt>...</tt><b>]</b><tt>
     46 <br>
     47 <br>
     48 zcat </tt><b>[</b><i>file</i><tt>...</tt><b>]</b><tt>
     49 <img src="../images/opt-end.gif" alt="[Option End]" border=0>
     50 </code></div>
     51 <br>
     52 </tt>
     53 </blockquote><h4 class="mansect"><a name = "tag_20_23_03"></a>DESCRIPTION</h4><blockquote>
     54 <p>
     55 The
     56 <i>compress</i>
     57 utility, when the
     58 <b>-d</b>
     59 option is not specified, shall apply the compression algorithm identified
     60 by the
     61 <b>-g</b>
     62 option or the
     63 <b>-m</b>
     64 <i>algo</i>
     65 option to the named files to attempt to reduce their size without loss
     66 of information. The compress utility with the
     67 <b>-d</b>
     68 option shall apply the appropriate decompression algorithm to the
     69 named files to restore the data to their original state.
     70 <p>
     71 The
     72 <i>uncompress</i>
     73 utility shall be equivalent to
     74 <i>compress</i>
     75 <b>-d</b>.
     76 The
     77 <i>zcat</i>
     78 utility shall be equivalent to
     79 <i>compress</i>
     80 <b>-c -d</b>.
     81 If multiple
     82 <i>file</i>
     83 operands are specified, the decompressed data from each input file
     84 shall be concatenated to standard output.
     85 <p>
     86 When compressing data, unless the
     87 <b>-c</b>
     88 option is specified, after an input file other than standard input has
     89 been compressed, the compressed data from the input file shall be
     90 stored in a file with the same pathname as the input file but with an
     91 added suffix. The added suffix shall be the suffix associated with the
     92 algorithm (see the algorithms in
     93 <a href="#tagtcjh_17">
     94 Compression algorithms, algo option-argument values, and suffixes
     95 </a>
     96 ).
     97 If appending the suffix would make the size of the last component of
     98 the output file's pathname exceed
     99 {NAME_MAX}
    100 bytes, the command shall fail. If appending the suffix would make the
    101 size of the pathname exceed
    102 {PATH_MAX}
    103 bytes, the command may fail.
    104 <p>
    105 When decompressing data, unless the
    106 <b>-c</b>
    107 option is specified, after an input file other than standard input has
    108 been decompressed, the decompressed data from the input file shall be
    109 stored in a file with the same pathname as the input file but with the
    110 suffix associated with the algorithm removed.
    111 <sup>[<a href="javascript:open_code('OB')">OB</a>]</sup>
    112 <img src="../images/opt-start.gif" alt="[Option Start]" border=0>
    113 &nbsp;If
    114 <i>file</i>
    115 has no suffix associated with a known compression algorithm or
    116 <i>file</i>
    117 does not exist and does not have a
    118 <b>.Z</b>
    119 suffix,
    120 <i>file</i>
    121 shall be used as the name of the output file, and the default suffix
    122 <b>.Z</b>
    123 shall be appended to
    124 <i>file</i>
    125 to form the input pathname.
    126 <img src="../images/opt-end.gif" alt="[Option End]" border=0>
    127 The behavior is unspecified if the input pathname ends with a suffix
    128 other than the suffix associated with the algorithm used to compress
    129 the data. When the
    130 <b>-c</b>
    131 option is specified,
    132 <i>file</i>
    133 can have any suffix, or no suffix, and the utility shall use
    134 <i>file</i>
    135 as the input file and examine the file's contents to determine which
    136 algorithm to use to decompress the data (it is not an error if
    137 <i>file</i>
    138 does not have a suffix that matches the suffix associated with the
    139 compression algorithm).
    140 <p>
    141 When compressing or decompressing a file other than standard input and the
    142 <b>-c</b>
    143 option is not specified, if the invoking process has sufficient privilege,
    144 the ownership, modes, access time, and modification time of the output
    145 file shall match the ownership, modes, access time, and modification
    146 time of the input file. After the output file has been successfully
    147 created, the input file shall be removed if the invoking process has
    148 sufficient privileges. If the invoking process does not have sufficient
    149 privileges to remove the input file (for example, if the directory has
    150 the S_ISVTX bit set) the behavior depends on whether the
    151 <b>-f</b>
    152 option is specified: if
    153 <b>-f</b>
    154 is not specified, the output file shall be removed, a diagnostic
    155 message shall be written and the utility shall continue processing
    156 other files but the final exit status shall be non-zero; if
    157 <b>-f</b>
    158 is specified, the output file shall not be removed and it is
    159 unspecified whether the inability to remove the input file is treated
    160 as an error. If it is not treated as an error, a warning message may
    161 be written to standard error
    162 <p>
    163 If no
    164 <i>file</i>
    165 operands are specified, standard input shall be compressed or
    166 decompressed to standard output.
    167 <p>
    168 <sup>[<a href="javascript:open_code('OB')">OB</a>]</sup>
    169 <img src="../images/opt-start.gif" alt="[Option Start]" border=0>
    170 If an input file that is to be removed after processing has multiple
    171 hard links, the
    172 <i>compress</i>
    173 and
    174 <i>uncompress</i>
    175 utilities may write a diagnostic message to standard error and do
    176 nothing with the file; this behavior may depend on whether the
    177 <b>-f</b>
    178 option is specified. If a diagnostic message is written, the final
    179 exit status shall be non-zero.
    180 <img src="../images/opt-end.gif" alt="[Option End]" border=0>
    181 </blockquote><h4 class="mansect"><a name = "tag_20_23_04"></a>OPTIONS</h4><blockquote>
    182 <p>
    183 The
    184 <i>compress</i>,
    185 <i>uncompress</i>,
    186 and
    187 <i>zcat</i>
    188 utilities shall conform to XBD
    189 <a href="../basedefs/V1_chap12.html#tag_12_02">
    190 <i>12.2 Utility Syntax Guidelines</i>
    191 </a>
    192 ,
    193 except that Guideline 1 does not apply to
    194 <i>uncompress</i>
    195 since the utility name has ten letters.
    196 <p>
    197 The following options shall be supported:
    198 <dl compact><dd>
    199 <p><dt><b>-b&nbsp;</b><i>value</i><dd>If the compression algorithm is LZW,
    200 <i>value</i>
    201 specifies the maximum number of bits to use in a code. For a
    202 conforming application, the
    203 <i>value</i>
    204 argument shall be:
    205 <pre>
    206 <tt>9 &lt;= </tt><i>value</i><tt> &lt;= 16
    207 </tt></pre>
    208 <p>
    209 The implementation may allow values of greater than 16. The default
    210 shall be 14, 15, or 16.
    211 <p>
    212 If the compression algorithm is DEFLATE,
    213 <i>value</i>
    214 specifies the compression level. For a conforming application, the
    215 <i>value</i>
    216 argument shall be:
    217 <pre>
    218 <tt>1 &lt;= </tt><i>value</i><tt> &lt;= 9
    219 </tt></pre>
    220 <p>
    221 The default shall be 6.
    222 <p>
    223 For other algorithms, value specifies implementation-defined tuning.
    224 <p><dt><b>-c</b><dd>Write to standard output; the input files shall not be changed, and no
    225 output files shall be created.
    226 <p><dt><b>-d</b><dd>Decompress files. When invoked with the
    227 <b>-d</b>
    228 option, the
    229 <i>compress</i>
    230 utility shall restore previously compressed files to their original state.
    231 <p><dt><b>-f</b><dd>Force compression or decompression of file, even if it does not (for
    232 compression) actually reduce the size of the file, or if the
    233 corresponding output file already exists. If the
    234 <b>-f</b>
    235 option is not given and the standard input is a terminal, the user
    236 shall be prompted as to whether an existing output file should be
    237 overwritten. If the response is affirmative, the existing file shall
    238 be overwritten. If the standard input is not a terminal and
    239 <b>-f</b>
    240 is not given,
    241 <i>compress</i>
    242 or
    243 <i>uncompress</i>
    244 shall write a diagnostic message to standard error, the existing file
    245 shall not be overwritten, and the utility shall exit with a status
    246 greater than zero. If the
    247 <b>-f</b>
    248 option is specified and an input file other than standard input has
    249 multiple hard links, it is implementation-defined whether the input
    250 file is unlinked after the corresponding output file is successfully
    251 written, or if processing of that file is skipped and a diagnostic
    252 message is written to standard error.
    253 <p><dt><b>-g</b><dd>Equivalent to
    254 <b>-m</b>
    255 <i>gzip</i>.
    256 <p><dt><b>-m </b><i>algo</i><dd>Use the algorithm defined by
    257 <i>algo</i>
    258 to compress the files. The following algorithms shall be supported:
    259 <br>
    260 <p class="caption"><xref table="Compression algorithms, algo option-argument values, and suffixes"><a name="tagtcjh_17"></a>
    261 Table: Compression algorithms, algo option-argument values, and suffixes</p>
    262 
    263 
    264 <p>
    265 <center>
    266 <p>
    267 <table border=1 cellpadding=3 align=center>
    268 <tr valign=top><th align=center><p class="tent"><b>Algorithm</b></p></th>
    269 <th align=center><p class="tent">algo</p></th>
    270 <th align=center><p class="tent"><b>Filename Suffix</b></p></th>
    271 </p></tr>
    272 <tr valign=top><td align=left><p class="tent">Adaptive LZW
    273 <td align=left><p class="tent"><b>lzw</b>
    274 <td align=left><p class="tent"><b>.Z</b>
    275 </p></tr>
    276 <tr valign=top><td align=left><p class="tent">RFC1951 DEFLATE
    277 <td align=left><p class="tent"><b>deflate</b>
    278 <td align=left><p class="tent"><b>.gz</b>
    279 </p></tr>
    280 <tr valign=top><td align=left><p class="tent">Synonym for DEFLATE
    281 <td align=left><p class="tent"><b>gzip</b>
    282 <td align=left><p class="tent"><b>.gz</b>
    283 </tr>
    284 </table>
    285 </center>
    286 <p class="tent">
    287 Other implementation-defined algorithms may be supported.
    288 <p class="tent">
    289 If neither of the
    290 <b>-m</b>
    291 <i>algo</i>
    292 and
    293 <b>-g</b>
    294 options is specified,
    295 <b>lzw</b>
    296 shall be used as a default
    297 <i>algo</i>
    298 value. Specifying more than one of the mutually exclusive
    299 <b>-g</b>
    300 and
    301 <b>-m</b>
    302 <i>algo</i>
    303 options, or multiple
    304 <b>-m</b>
    305 <i>algo</i>
    306 options, shall not be considered an error. The last option specified
    307 shall determine the behavior of the utility.
    308 <p class="tent">
    309 On systems not supporting the selected algorithm, the input files
    310 shall not be changed and an exit status greater than two shall be
    311 returned.
    312 <basefont size=2>
    313 <dl><dt><b>Note:</b>
    314 <dd>The Lempel-Ziv compression algorithm is described in the now-expired
    315 US Patent 4464650, which was issued to William Eastman, Abraham Lempel,
    316 Jacob Ziv, and Martin Cohn on August 7th, 1984 and assigned to Sperry
    317 Corporation.
    318 <p class="tent">
    319 The Lempel-Ziv-Welch compression algorithm is described in the
    320 now-expired US Patent 4558302, which was issued to Terry A. Welch on
    321 December 10th, 1985 and assigned to Sperry Corporation.
    322 </dl>
    323 <basefont size=3>
    324 <p><dt><b>-v</b><dd>For
    325 <i>compress</i>,
    326 write the percentage reduction of each file to standard error. For
    327 <i>uncompress</i>,
    328 write messages to standard error concerning the expansion of each file.
    329 </dl>
    330 </blockquote><h4 class="mansect"><a name = "tag_20_23_05"></a>OPERANDS</h4><blockquote>
    331 <p>
    332 The following operand shall be supported:
    333 <dl compact><dd>
    334 <p><dt><i>file</i><dd>A pathname of a file to be compressed or decompressed. If a
    335 <i>file</i>
    336 is
    337 <tt>'-'</tt>,
    338 the utility shall read from standard input at that point in the
    339 sequence and write to standard output. If more than one
    340 <i>file</i>
    341 operand is
    342 <tt>'-'</tt>,
    343 the behavior is unspecified.
    344 </dl>
    345 </blockquote><h4 class="mansect"><a name = "tag_20_23_06"></a>STDIN</h4><blockquote>
    346 <p>
    347 The standard input shall be used only if no
    348 <i>file</i>
    349 operands are specified, or if a
    350 <i>file</i>
    351 operand is
    352 <tt>'-'</tt>.
    353 </blockquote><h4 class="mansect"><a name = "tag_20_23_07"></a>INPUT FILES</h4><blockquote>
    354 <p>
    355 If
    356 <i>file</i>
    357 operands are specified, the corresponding input files contain the data
    358 to be compressed or decompressed.
    359 </blockquote><h4 class="mansect"><a name = "tag_20_23_08"></a>ENVIRONMENT VARIABLES</h4><blockquote>
    360 <p>
    361 The following environment variables shall affect the execution of
    362 <i>compress</i>:
    363 <dl compact><dd>
    364 <p><dt><i>LANG</i><dd>Provide a default value for the internationalization variables that are
    365 unset or null. (See XBD
    366 <a href="../basedefs/V1_chap08.html#tag_08_02">
    367 <i>8.2 Internationalization Variables</i>
    368 </a>
    369 for the precedence of internationalization variables used to determine
    370 the values of locale categories.)
    371 <p><dt><i>LC_ALL</i><dd>If set to a non-empty string value, override the values of all the
    372 other internationalization variables.
    373 <p><dt><i>LC_COLLATE</i><dd><br>
    374 Determine the locale for the behavior of ranges, equivalence classes,
    375 and multi-character collating elements used in the extended regular
    376 expression defined for the
    377 <b>yesexpr</b>
    378 locale keyword in the
    379 <i>LC_MESSAGES</i>
    380 category.
    381 <p><dt><i>LC_CTYPE</i><dd>Determine the locale for the interpretation of sequences of bytes of text
    382 data as characters (for example, single-byte as opposed to multi-byte
    383 characters in arguments), the behavior of character classes used in the
    384 extended regular expression defined for the
    385 <b>yesexpr</b>
    386 locale keyword in the
    387 <i>LC_MESSAGES</i>
    388 category.
    389 <p><dt><i>LC_MESSAGES</i><dd><br>
    390 Determine the locale used to process affirmative responses, and the
    391 locale used to affect the format and contents of diagnostic messages,
    392 prompts, and the output from the
    393 <b>-v</b>
    394 option written to standard error.
    395 <p><dt><i>NLSPATH</i><dd>Determine the location of messages objects and message catalogs.
    396 </dl>
    397 </blockquote><h4 class="mansect"><a name = "tag_20_23_09"></a>ASYNCHRONOUS EVENTS</h4><blockquote>
    398 <p>
    399 Default.
    400 </blockquote><h4 class="mansect"><a name = "tag_20_23_10"></a>STDOUT</h4><blockquote>
    401 <p>
    402 For the
    403 <i>compress</i>
    404 and
    405 <i>uncompress</i>
    406 utilities, the standard output shall be used if no
    407 <i>file</i>
    408 operands are specified, if a
    409 <i>file</i>
    410 operand is
    411 <tt>'-'</tt>,
    412 or if the
    413 <b>-c</b>
    414 option is specified. Otherwise, the standard output shall not be used.
    415 <p class="tent">
    416 The
    417 <i>zcat</i>
    418 utility shall write the decompressed data to the standard output.
    419 </blockquote><h4 class="mansect"><a name = "tag_20_23_11"></a>STDERR</h4><blockquote>
    420 <p>
    421 The standard error shall be used only for diagnostic and prompt
    422 messages, the optional warning message described in DESCRIPTION, and
    423 the output from
    424 <b>-v</b>.
    425 </blockquote><h4 class="mansect"><a name = "tag_20_23_12"></a>OUTPUT FILES</h4><blockquote>
    426 <p>
    427 When decompressing input files other than standard input, the
    428 corresponding output files shall contain the decompressed input data.
    429 When compressing input files other than standard input, the
    430 corresponding output files shall contain the compressed input data.
    431 If the selected
    432 <i>algo</i>
    433 is
    434 <b>deflate</b>
    435 or
    436 <b>gzip</b>,
    437 the compressed output shall be in the GZIP format described in RFC 1952.
    438 For other algorithms, the compressed output file format is
    439 implementation-defined and interchange of such files between
    440 implementations (including access via unspecified file sharing
    441 mechanisms) is not required by POSIX.1-2024.
    442 </blockquote><h4 class="mansect"><a name = "tag_20_23_13"></a>EXTENDED DESCRIPTION</h4><blockquote>
    443 <p>
    444 None.
    445 </blockquote><h4 class="mansect"><a name = "tag_20_23_14"></a>EXIT STATUS</h4><blockquote>
    446 <p>
    447 The following exit values shall be returned for
    448 <i>compress</i>:
    449 <dl compact><dd>
    450 <p><dt>&nbsp;0<dd>Successful completion.
    451 <p><dt>&nbsp;1<dd>An error occurred.
    452 <p><dt>&nbsp;2<dd>One or more files were not compressed because they would have increased
    453 in size (and the
    454 <b>-f</b>
    455 option was not specified).
    456 <p><dt>&gt;2<dd>An error occurred.
    457 </dl>
    458 <p class="tent">
    459 The following exit values shall be returned for
    460 <i>uncompress</i>
    461 and
    462 <i>zcat</i>:
    463 <dl compact><dd>
    464 <p><dt>&nbsp;0<dd>Successful completion.
    465 <p><dt>&gt;0<dd>An error occurred.
    466 </dl>
    467 </blockquote><h4 class="mansect"><a name = "tag_20_23_15"></a>CONSEQUENCES OF ERRORS</h4><blockquote>
    468 <p>
    469 If an error occurs while compressing or decompressing an input file
    470 other than standard input, the input file shall remain unmodified.
    471 </blockquote>
    472 <hr><div class="box"><em>The following sections are informative.</em></div>
    473 <blockquote>
    474 </blockquote><h4 class="mansect"><a name = "tag_20_23_16"></a>APPLICATION USAGE</h4><blockquote>
    475 <p>
    476 The amount of compression obtained depends on the size of the input,
    477 the number of bits
    478 per code, and the distribution of common substrings. Typically, text
    479 such as source code or English is reduced by 50-60%. Compression is
    480 generally much better than that achieved by Huffman coding
    481 or adaptive Huffman coding (<i>compact</i>),
    482 and takes less time to compute.
    483 <p class="tent">
    484 Although
    485 <i>compress</i>
    486 strictly follows the default actions upon receipt of a signal or when
    487 an error occurs, some unexpected results may occur. In some
    488 implementations it is likely that a partially compressed file is left
    489 in place, alongside its uncompressed input file. Since the general
    490 operation of
    491 <i>compress</i>
    492 is to delete the uncompressed file only after the
    493 <b>.Z</b>
    494 file has been successfully filled, an application should always
    495 carefully check the exit status of
    496 <i>compress</i>
    497 before arbitrarily deleting files that have like-named neighbors with
    498 <b>.Z</b>
    499 suffixes.
    500 <p class="tent">
    501 In addition to trying
    502 <i>file</i>
    503 and
    504 <i>file</i><b>.Z</b>
    505 when looking for a file to decompress, some implementations of
    506 <i>uncompress</i>
    507 and
    508 <i>zcat</i>
    509 also try suffixes for other known compression algorithms if neither
    510 <i>file</i>
    511 nor
    512 <i>file</i><b>.Z</b>
    513 is found. This version of the standard allows, but does not require
    514 this behavior. Portable applications should always specify the full
    515 pathname (including the suffix) of files to be decompressed.
    516 </blockquote><h4 class="mansect"><a name = "tag_20_23_17"></a>EXAMPLES</h4><blockquote>
    517 <p>
    518 None.
    519 </blockquote><h4 class="mansect"><a name = "tag_20_23_18"></a>RATIONALE</h4><blockquote>
    520 <p>
    521 Earlier versions of this standard limited the number of bits used by
    522 conforming applications for the
    523 <b>lzw</b>
    524 algorithm to 14 due to address space limitations on 16-bit
    525 architectures. Using 15 or 16 is a much more common default when using
    526 current hardware.
    527 <p class="tent">
    528 Earlier versions of this standard only supported LZW compression. The
    529 standard developers noted that existing implementations added other
    530 compression utilities, such as
    531 <i>gzip</i>,
    532 and found it desirable to support this widespread usage. Some
    533 implementations had extended the
    534 <i>compress</i>
    535 utility to support such other schemes. The standard developers
    536 generalized this practice by the addition of the
    537 <b>-m</b>
    538 option, even though this was not previous practice.
    539 <p class="tent">
    540 The
    541 <i>uncompress</i>
    542 <b>-d</b>
    543 option is added to match undocumented existing practice of tested
    544 implementations.
    545 </blockquote><h4 class="mansect"><a name = "tag_20_23_19"></a>FUTURE DIRECTIONS</h4><blockquote>
    546 <p>
    547 If this utility is directed to create a new directory entry that
    548 contains any bytes that have the encoded value of a
    549 &lt;newline&gt;
    550 character, implementations are encouraged to treat this as an error.
    551 A future version of this standard may require implementations to treat
    552 this as an error.
    553 <p class="tent">
    554 When decompressing a file, the requirement to add
    555 <b>.Z</b>
    556 to a
    557 <i>file</i>
    558 operand if the given pathname does not include a suffix associated
    559 with a known compression algorithm or if
    560 <i>file</i>
    561 does not exist and does not already have a
    562 <b>.Z</b>
    563 extension is an obsolescent feature and may be removed in a future version.
    564 </blockquote><h4 class="mansect"><a name = "tag_20_23_20"></a>SEE ALSO</h4><blockquote>
    565 <p>
    566 XBD
    567 <a href="../basedefs/V1_chap08.html#tag_08">
    568 <i>8. Environment Variables</i>
    569 </a>
    570 ,
    571 <a href="../basedefs/V1_chap12.html#tag_12_02">
    572 <i>12.2 Utility Syntax Guidelines</i>
    573 </a>
    574 </blockquote><h4 class="mansect"><a name = "tag_20_23_21"></a>CHANGE HISTORY</h4><blockquote>
    575 <p>
    576 First released in Issue 4.
    577 </blockquote><h4 class="mansect"><a name = "tag_20_23_22"></a>Issue 6</h4><blockquote>
    578 <p>
    579 The normative text is reworded to avoid use of the term &quot;must&quot;
    580 for application requirements.
    581 <p class="tent">
    582 An error case is added for systems not supporting adaptive Lempel-Ziv
    583 coding.
    584 </blockquote><h4 class="mansect"><a name = "tag_20_23_23"></a>Issue 7</h4><blockquote>
    585 <p>
    586 SD5-XCU-ERN-97 is applied, updating the SYNOPSIS.
    587 <p class="tent">
    588 Austin Group Interpretation 1003.1-2001 #125 is applied, revising
    589 the ENVIRONMENT VARIABLES section.
    590 </blockquote><h4 class="mansect"><a name = "tag_20_23_24"></a>Issue 8</h4><blockquote>
    591 <p>
    592 Austin Group Defect 251 is applied, encouraging implementations to
    593 disallow the creation of filenames containing any bytes that have the
    594 encoded value of a
    595 &lt;newline&gt;
    596 character.
    597 <p class="tent">
    598 Austin Group Defect 1041 is applied, combining the
    599 <i>compress</i>,
    600 <i>uncompress</i>
    601 and
    602 <i>zcat</i>
    603 pages into one and extensively modifying most sections.
    604 <p class="tent">
    605 Austin Group Defect 1122 is applied, changing the description of
    606 <i>NLSPATH .
    607 </i></blockquote>
    608 <div class="box"><em>End of informative text.</em></div><hr>
    609 <blockquote>
    610 </blockquote>
    611 <p>&nbsp;</p>
    612 <a href="#top"><span class="topOfPage">return to top of page</span></a><br>
    613 <hr size="2" noshade>
    614 <center><font size="2">UNIX&reg; is a registered Trademark of The Open Group.<br>
    615 POSIX&trade; is a Trademark of The IEEE.<br>
    616 Copyright &copy; 2001-2024 The IEEE and The Open Group, All Rights Reserved<br>
    617 [ <a href="../mindex.html">Main Index</a> | 
    618 <a href="../basedefs/contents.html">XBD</a> | 
    619 <a href="../functions/contents.html">XSH</a> | 
    620 <a href="../utilities/contents.html">XCU</a> | 
    621 <a href="../xrat/contents.html">XRAT</a> ]
    622 </font></center>
    623 <hr size="2" noshade>
    624 
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