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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>strxfrm</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="strxfrm"></a> <a name="tag_03_748"></a><!-- strxfrm --> <!--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_03_748_01"></a>NAME</h4><blockquote>strxfrm - string transformation</blockquote><h4><a name="tag_03_748_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><p><code><tt>#include <<a href="../basedefs/string.h.html">string.h</a>><br><br> size_t strxfrm(char *restrict</tt> <i>s1</i><tt>, const char *restrict</tt> <i>s2</i><tt>, size_t</tt> <i>n</i><tt>);<br></tt></code></p></blockquote><h4><a name="tag_03_748_03"></a>DESCRIPTION</h4><blockquote><div class="box"><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]"border="0"> The functionality described on this reference page is aligned with the ISO C standard. Any conflict between therequirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers tothe ISO C standard. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></div><p>The <i>strxfrm</i>() function shall transform the string pointed to by <i>s2</i> and place the resulting string into the arraypointed to by <i>s1</i>. The transformation is such that if <a href="../functions/strcmp.html"><i>strcmp</i>()</a> is applied totwo transformed strings, it shall return a value greater than, equal to, or less than 0, corresponding to the result of <a href="../functions/strcoll.html"><i>strcoll</i>()</a> applied to the same two original strings. No more than <i>n</i> bytes are placedinto the resulting array pointed to by <i>s1</i>, including the terminating null byte. If <i>n</i> is 0, <i>s1</i> is permitted tobe a null pointer. If copying takes place between objects that overlap, the behavior is undefined.</p><p><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> The<i>strxfrm</i>() function shall not change the setting of <i>errno</i> if successful.</p><p>Since no return value is reserved to indicate an error, an application wishing to check for error situations should set<i>errno</i> to 0, then call <i>strxfrm</i>(), then check <i>errno</i>. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></p></blockquote><h4><a name="tag_03_748_04"></a>RETURN VALUE</h4><blockquote><p>Upon successful completion, <i>strxfrm</i>() shall return the length of the transformed string (not including the terminatingnull byte). If the value returned is <i>n</i> or more, the contents of the array pointed to by <i>s1</i> are unspecified.</p><p><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> Onerror, <i>strxfrm</i>() may set <i>errno</i> but no return value is reserved to indicate an error. <img src="../images/opt-end.gif"alt="[Option End]" border="0"></p></blockquote><h4><a name="tag_03_748_05"></a>ERRORS</h4><blockquote><p>The <i>strxfrm</i>() function may fail if:</p><dl compact><dt>[EINVAL]</dt><dd><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0">The string pointed to by the <i>s2</i> argument contains characters outside the domain of the collating sequence. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd></dl></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_748_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_748_07"></a>APPLICATION USAGE</h4><blockquote><p>The transformation function is such that two transformed strings can be ordered by <a href="../functions/strcmp.html"><i>strcmp</i>()</a> as appropriate to collating sequence information in the program's locale (category<i>LC_COLLATE ).</i></p><p>The fact that when <i>n</i> is 0 <i>s1</i> is permitted to be a null pointer is useful to determine the size of the <i>s1</i>array prior to making the transformation.</p></blockquote><h4><a name="tag_03_748_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_748_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_748_10"></a>SEE ALSO</h4><blockquote><p><a href="strcmp.html"><i>strcmp</i>()</a> , <a href="strcoll.html"><i>strcoll</i>()</a> , the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/string.h.html"><i><string.h></i></a></p></blockquote><h4><a name="tag_03_748_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 3. Included for alignment with the ISO C standard.</p></blockquote><h4><a name="tag_03_748_12"></a>Issue 5</h4><blockquote><p>The DESCRIPTION is updated to indicate that <i>errno</i> does not change if the function is successful.</p></blockquote><h4><a name="tag_03_748_13"></a>Issue 6</h4><blockquote><p>Extensions beyond the ISO C standard are marked.</p><p>The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:</p><ul><li><p>In the RETURN VALUE and ERRORS sections, the [EINVAL] optional error condition is added if no conversion could be performed.</p></li></ul><p>The <i>strxfrm</i>() prototype is updated for alignment with the ISO/IEC 9899:1999 standard.</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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