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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) 2001-2004 IEEE and The Open Group, All Rights Reserved --><title>wcsrtombs</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="wcsrtombs"></a> <a name="tag_03_839"></a><!-- wcsrtombs --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2004 Edition<br>Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_03_839_01"></a>NAME</h4><blockquote>wcsrtombs - convert a wide-character string to a character string (restartable)</blockquote><h4><a name="tag_03_839_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><p><code><tt>#include <<a href="../basedefs/wchar.h.html">wchar.h</a>><br><br> size_t wcsrtombs(char *restrict</tt> <i>dst</i><tt>, const wchar_t **restrict</tt> <i>src</i><tt>,<br> size_t</tt> <i>len</i><tt>, mbstate_t *restrict</tt> <i>ps</i><tt>);<br></tt></code></p></blockquote><h4><a name="tag_03_839_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>wcsrtombs</i>() function shall convert a sequence of wide characters from the array indirectly pointed to by <i>src</i>into a sequence of corresponding characters, beginning in the conversion state described by the object pointed to by <i>ps</i>. If<i>dst</i> is not a null pointer, the converted characters shall then be stored into the array pointed to by <i>dst</i>. Conversioncontinues up to and including a terminating null wide character, which shall also be stored. Conversion shall stop earlier in thefollowing cases:</p><ul><li><p>When a code is reached that does not correspond to a valid character</p></li><li><p>When the next character would exceed the limit of <i>len</i> total bytes to be stored in the array pointed to by <i>dst</i> (and<i>dst</i> is not a null pointer)</p></li></ul><p>Each conversion shall take place as if by a call to the <a href="../functions/wcrtomb.html"><i>wcrtomb</i>()</a> function.</p><p>If <i>dst</i> is not a null pointer, the pointer object pointed to by <i>src</i> shall be assigned either a null pointer (ifconversion stopped due to reaching a terminating null wide character) or the address just past the last wide character converted(if any). If conversion stopped due to reaching a terminating null wide character, the resulting state described shall be theinitial conversion state.</p><p>If <i>ps</i> is a null pointer, the <i>wcsrtombs</i>() function shall use its own internal <b>mbstate_t</b> object, which isinitialized at program start-up to the initial conversion state. Otherwise, the <b>mbstate_t</b> object pointed to by <i>ps</i>shall be used to completely describe the current conversion state of the associated character sequence. The implementation shallbehave as if no function defined in this volume of IEEE Std 1003.1-2001 calls <i>wcsrtombs</i>().</p><p><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> Ifthe application uses any of the _POSIX_THREAD_SAFE_FUNCTIONS or _POSIX_THREADS functions, the application shall ensure that the<i>wcsrtombs</i>() function is called with a non-NULL <i>ps</i> argument. <img src="../images/opt-end.gif" alt="[Option End]"border="0"></p><p>The behavior of this function shall be affected by the <i>LC_CTYPE</i> category of the current locale.</p></blockquote><h4><a name="tag_03_839_04"></a>RETURN VALUE</h4><blockquote><p>If conversion stops because a code is reached that does not correspond to a valid character, an encoding error occurs. In thiscase, the <i>wcsrtombs</i>() function shall store the value of the macro [EILSEQ] in <i>errno</i> and return (<b>size_t</b>)-1; theconversion state is undefined. Otherwise, it shall return the number of bytes in the resulting character sequence, not includingthe terminating null (if any).</p></blockquote><h4><a name="tag_03_839_05"></a>ERRORS</h4><blockquote><p>The <i>wcsrtombs</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"><i>ps</i> points to an object that contains an invalid conversion state. <img src="../images/opt-end.gif" alt="[Option End]"border="0"></dd><dt>[EILSEQ]</dt><dd>A wide-character code does not correspond to a valid character.</dd></dl></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_839_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_839_07"></a>APPLICATION USAGE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_839_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_839_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_839_10"></a>SEE ALSO</h4><blockquote><p><a href="mbsinit.html"><i>mbsinit</i>()</a>, <a href="wcrtomb.html"><i>wcrtomb</i>()</a>, the Base Definitions volume ofIEEE Std 1003.1-2001, <a href="../basedefs/wchar.h.html"><i><wchar.h></i></a></p></blockquote><h4><a name="tag_03_839_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 5. Included for alignment with ISO/IEC 9899:1990/Amendment 1:1995 (E).</p></blockquote><h4><a name="tag_03_839_12"></a>Issue 6</h4><blockquote><p>In the DESCRIPTION, a note on using this function in a threaded application is added.</p><p>Extensions beyond the ISO C standard are marked.</p><p>The DESCRIPTION is updated to avoid use of the term "must" for application requirements.</p><p>The <i>wcsrtombs</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 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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