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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy, see www.w3.org"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 --><!-- Copyright (c) 2001-2003 The Open Group, All Rights Reserved --><title>wc</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="wc"></a> <a name="tag_04_169"></a><!-- wc --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2003 Edition<br>Copyright © 2001-2003 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_04_169_01"></a>NAME</h4><blockquote>wc - word, line, and byte or character count</blockquote><h4><a name="tag_04_169_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><p><code><tt>wc</tt> <b>[</b><tt>-c|-m</tt><b>][</b><tt>-lw</tt><b>][</b><i>file</i><tt>...</tt><b>]</b></code></p></blockquote><h4><a name="tag_04_169_03"></a>DESCRIPTION</h4><blockquote><p>The <i>wc</i> utility shall read one or more input files and, by default, write the number of <newline>s, words, and bytescontained in each input file to the standard output.</p><p>The utility also shall write a total count for all named files, if more than one input file is specified.</p><p>The <i>wc</i> utility shall consider a <i>word</i> to be a non-zero-length string of characters delimited by white space.</p></blockquote><h4><a name="tag_04_169_04"></a>OPTIONS</h4><blockquote><p>The <i>wc</i> utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/xbd_chap12.html#tag_12_02">Section 12.2, Utility Syntax Guidelines</a>.</p><p>The following options shall be supported:</p><dl compact><dt><b>-c</b></dt><dd>Write to the standard output the number of bytes in each input file.</dd><dt><b>-l</b></dt><dd>Write to the standard output the number of <newline>s in each input file.</dd><dt><b>-m</b></dt><dd>Write to the standard output the number of characters in each input file.</dd><dt><b>-w</b></dt><dd>Write to the standard output the number of words in each input file.</dd></dl><p>When any option is specified, <i>wc</i> shall report only the information requested by the specified options.</p></blockquote><h4><a name="tag_04_169_05"></a>OPERANDS</h4><blockquote><p>The following operand shall be supported:</p><dl compact><dt><i>file</i></dt><dd>A pathname of an input file. If no <i>file</i> operands are specified, the standard input shall be used.</dd></dl></blockquote><h4><a name="tag_04_169_06"></a>STDIN</h4><blockquote><p>The standard input shall be used only if no <i>file</i> operands are specified. See the INPUT FILES section.</p></blockquote><h4><a name="tag_04_169_07"></a>INPUT FILES</h4><blockquote><p>The input files may be of any type.</p></blockquote><h4><a name="tag_04_169_08"></a>ENVIRONMENT VARIABLES</h4><blockquote><p>The following environment variables shall affect the execution of <i>wc</i>:</p><dl compact><dt><i>LANG</i></dt><dd>Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/xbd_chap08.html#tag_08_02">Section 8.2, Internationalization Variables</a> forthe precedence of internationalization variables used to determine the values of locale categories.)</dd><dt><i>LC_ALL</i></dt><dd>If set to a non-empty string value, override the values of all the other internationalization variables.</dd><dt><i>LC_CTYPE</i></dt><dd>Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte asopposed to multi-byte characters in arguments and input files) and which characters are defined as white space characters.</dd><dt><i>LC_MESSAGES</i></dt><dd>Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error andinformative messages written to standard output.</dd><dt><i>NLSPATH</i></dt><dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0">Determine the location of message catalogs for the processing of <i>LC_MESSAGES .</i> <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd></dl></blockquote><h4><a name="tag_04_169_09"></a>ASYNCHRONOUS EVENTS</h4><blockquote><p>Default.</p></blockquote><h4><a name="tag_04_169_10"></a>STDOUT</h4><blockquote><p>By default, the standard output shall contain an entry for each input file of the form:</p><pre><tt>"%d %d %d %s\n", <</tt><i>newlines</i><tt>>, <</tt><i>words</i><tt>>, <</tt><i>bytes</i><tt>>, <</tt><i>file</i><tt>></tt></pre><p>If the <b>-m</b> option is specified, the number of characters shall replace the <<i>bytes</i>> field in this format.</p><p>If any options are specified and the <b>-l</b> option is not specified, the number of <newline>s shall not be written.</p><p>If any options are specified and the <b>-w</b> option is not specified, the number of words shall not be written.</p><p>If any options are specified and neither <b>-c</b> nor <b>-m</b> is specified, the number of bytes or characters shall not bewritten.</p><p>If no input <i>file</i> operands are specified, no name shall be written and no <blank>s preceding the pathname shall bewritten.</p><p>If more than one input <i>file</i> operand is specified, an additional line shall be written, of the same format as the otherlines, except that the word <b>total</b> (in the POSIX locale) shall be written instead of a pathname and the total of each columnshall be written as appropriate. Such an additional line, if any, is written at the end of the output.</p></blockquote><h4><a name="tag_04_169_11"></a>STDERR</h4><blockquote><p>The standard error shall be used only for diagnostic messages.</p></blockquote><h4><a name="tag_04_169_12"></a>OUTPUT FILES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_169_13"></a>EXTENDED DESCRIPTION</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_169_14"></a>EXIT STATUS</h4><blockquote><p>The following exit values shall be returned:</p><dl compact><dt> 0</dt><dd>Successful completion.</dd><dt>>0</dt><dd>An error occurred.</dd></dl></blockquote><h4><a name="tag_04_169_15"></a>CONSEQUENCES OF ERRORS</h4><blockquote><p>Default.</p></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_04_169_16"></a>APPLICATION USAGE</h4><blockquote><p>The <b>-m</b> option is not a switch, but an option at the same level as <b>-c</b>. Thus, to produce the full default outputwith character counts instead of bytes, the command required is:</p><pre><tt>wc -mlw</tt></pre></blockquote><h4><a name="tag_04_169_17"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_169_18"></a>RATIONALE</h4><blockquote><p>The output file format pseudo- <a href="../functions/printf.html"><i>printf</i>()</a> string differs from the System V versionof <i>wc</i>:</p><pre><tt>"%7d%7d%7d %s\n"</tt></pre><p>which produces possibly ambiguous and unparsable results for very large files, as it assumes no number shall exceed sixdigits.</p><p>Some historical implementations use only <space>, <tab>, and <newline> as word separators. The equivalent ofthe ISO C standard <a href="../functions/isspace.html"><i>isspace</i>()</a> function is more appropriate.</p><p>The <b>-c</b> option stands for "character" count, even though it counts bytes. This stems from the sometimes erroneoushistorical view that bytes and characters are the same size. Due to international requirements, the <b>-m</b> option (reminiscentof "multi-byte") was added to obtain actual character counts.</p><p>Early proposals only specified the results when input files were text files. The current specification more closely matcheshistorical practice. (Bytes, words, and <newline>s are counted separately and the results are written when an end-of-file isdetected.)</p><p>Historical implementations of the <i>wc</i> utility only accepted one argument to specify the options <b>-c</b>, <b>-l</b>, and<b>-w</b>. Some of them also had multiple occurrences of an option cause the corresponding count to be written multiple times andhad the order of specification of the options affect the order of the fields on output, but did not document either of these.Because common usage either specifies no options or only one option, and because none of this was documented, the changes requiredby this volume of IEEE Std 1003.1-2001 should not break many historical applications (and do not break any historicalconforming applications).</p></blockquote><h4><a name="tag_04_169_19"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_04_169_20"></a>SEE ALSO</h4><blockquote><p><a href="cksum.html"><i>cksum</i></a></p></blockquote><h4><a name="tag_04_169_21"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 2.</p></blockquote><div class="box"><em>End of informative text.</em></div><hr><hr size="2" noshade><center><font size="2"><!--footer start-->UNIX ® is a registered Trademark of The Open Group.<br>POSIX ® is a registered Trademark of The IEEE.<br>[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href="../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>]</font></center><!--footer end--><hr size="2" noshade></body></html>⌨️ 快捷键说明
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