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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"><html><head><!-- Copyright 1997 The Open Group, All Rights Reserved --><title>sum</title></head><body bgcolor=white><center><font size=2>The Single UNIX ® Specification, Version 2<br>Copyright © 1997 The Open Group</font></center><hr size=2 noshade><h4><a name = "tag_001_014_2144"> </a>NAME</h4><blockquote>sum - print checksum and block count of a file (<b><a href="intro.html#tag_001_003_003">LEGACY</a></b>)</blockquote><h4><a name = "tag_001_014_2145"> </a>SYNOPSIS</h4><blockquote><pre><code>sum <b>[</b>-r<b>][</b><i>file</i>...<b>]</b></code></pre></blockquote><h4><a name = "tag_001_014_2146"> </a>DESCRIPTION</h4><blockquote>The<i>sum</i>utilitycalculates and writes a checksum for the named fileto standard outputand also writes the space used by the file, in 512-byte units.</blockquote><h4><a name = "tag_001_014_2147"> </a>OPTIONS</h4><blockquote>The<i>sum</i>utility supports the <b>XBD</b> specification, <a href="../xbd/utilconv.html#usg"><b>Utility Syntax Guidelines</b> </a> .The following options are supported:<p><dl compact><dt><b>-r</b><dd>Use an alternative algorithm in computing the checksum.</dl></blockquote><h4><a name = "tag_001_014_2148"> </a>OPERANDS</h4><blockquote>The following operands are supported:<dl compact><dt><i>file</i><dd>A pathname of a file.If no files are named, the standard input is read.</dl></blockquote><h4><a name = "tag_001_014_2149"> </a>STDIN</h4><blockquote>The standard input is any type of file, used only if no<i>file</i>operands are specified.</blockquote><h4><a name = "tag_001_014_2150"> </a>INPUT FILES</h4><blockquote>The input files are of any file type.</blockquote><h4><a name = "tag_001_014_2151"> </a>ENVIRONMENT VARIABLES</h4><blockquote>The following environment variables may affect the execution of<i>sum</i>:<dl compact><dt><i>LANG</i><dd>Provide a default value for the internationalisation variablesthat are unset or null.If<i>LANG</i>is unset or null, the corresponding value from theimplementation-dependent default locale will be used.If any of the internationalisation variables contains an invalid setting, theutility will behave as if none of the variables had been defined.<dt><i>LC_ALL</i><dd>If set to a non-empty string value,override the values of all the other internationalisation variables.<dt><i>LC_CTYPE</i><dd>Determine thelocale for the interpretation of sequences of bytes of text data ascharacters (for example, single- as opposed to multi-byte charactersin arguments).<dt><i>LC_MESSAGES</i><dd>Determine the locale that should be used to affectthe format and contents of diagnosticmessages written to standard error.<dt><i>NLSPATH</i><dd>Determine the location of message cataloguesfor the processing of<i>LC_MESSAGES .</i></dl></blockquote><h4><a name = "tag_001_014_2152"> </a>ASYNCHRONOUS EVENTS</h4><blockquote>Default.</blockquote><h4><a name = "tag_001_014_2153"> </a>STDOUT</h4><blockquote>For each file processed successfully,<i>sum</i>writes a line of the following format:<p><code><tt>"%u %d %s\n"</tt>, <<i>checksum</i>>,<<i>number of 512-byte units</i>>,<<i>pathname</i>></code><p>If the standard input is used for input, the pathname is omitted.</blockquote><h4><a name = "tag_001_014_2154"> </a>STDERR</h4><blockquote>Used only for diagnostic messages.</blockquote><h4><a name = "tag_001_014_2155"> </a>OUTPUT FILES</h4><blockquote>None.</blockquote><h4><a name = "tag_001_014_2156"> </a>EXTENDED DESCRIPTION</h4><blockquote>None.</blockquote><h4><a name = "tag_001_014_2157"> </a>EXIT STATUS</h4><blockquote>The following exit values are returned:<dl compact><dt>0<dd>Successful completion.<dt>>0<dd>An error occurred.</dl></blockquote><h4><a name = "tag_001_014_2158"> </a>CONSEQUENCES OF ERRORS</h4><blockquote>Default.</blockquote><h4><a name = "tag_001_014_2159"> </a>APPLICATION USAGE</h4><blockquote>It is not clear that the algorithms used in typical implementationsare portable, that is, the same checksum might not be producedfor the same input ondifferent systems.Portable applications should use<i><a href="cksum.html">cksum</a></i>.</blockquote><h4><a name = "tag_001_014_2160"> </a>EXAMPLES</h4><blockquote>None.</blockquote><h4><a name = "tag_001_014_2161"> </a>FUTURE DIRECTIONS</h4><blockquote>None.</blockquote><h4><a name = "tag_001_014_2162"> </a>SEE ALSO</h4><blockquote><i><a href="cksum.html">cksum</a></i>.<br></blockquote><hr size=2 noshade><center><font size=2>UNIX ® is a registered Trademark of The Open Group.<br>Copyright © 1997 The Open Group<br> [ <a href="../index.html">Main Index</a> | <a href="../xshix.html">XSH</a> | <a href="../xcuix.html">XCU</a> | <a href="../xbdix.html">XBD</a> | <a href="../cursesix.html">XCURSES</a> | <a href="../xnsix.html">XNS</a> ]</font></center><hr size=2 noshade></body></html>⌨️ 快捷键说明
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