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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>fgetwc</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_000_005_068"> </a>NAME</h4><blockquote>fgetwc - get a wide-character code from a stream</blockquote><h4><a name = "tag_000_005_069"> </a>SYNOPSIS</h4><blockquote><pre><code>#include <<a href="stdio.h.html">stdio.h</a>>#include <<a href="wchar.h.html">wchar.h</a>>wint_t fgetwc(FILE *<i>stream</i>);</code></pre></blockquote><h4><a name = "tag_000_005_070"> </a>DESCRIPTION</h4><blockquote>The<i>fgetwc()</i>function obtains the next character (if present)from the input stream pointed to by<i>stream</i>,converts that to the corresponding wide-character codeand advances the associated file position indicator for thestream (if defined).<p>If an error occurs, the resulting value of the file positionindicator for the stream is indeterminate.<p>The<i>fgetwc()</i>function may mark the<i>st_atime</i>field of the file associated with<i>stream</i>for update.The<i>st_atime</i>field will be marked for update by the first successfulexecution of<i><a href="fgetc.html">fgetc()</a></i>,<i><a href="fgets.html">fgets()</a></i>,<i>fgetwc()</i>,<i><a href="fgetws.html">fgetws()</a></i>,<i><a href="fread.html">fread()</a></i>,<i><a href="fscanf.html">fscanf()</a></i>,<i><a href="getc.html">getc()</a></i>,<i><a href="getchar.html">getchar()</a></i>,<i><a href="gets.html">gets()</a></i>or<i><a href="scanf.html">scanf()</a></i>using<i>stream</i>that returns data not supplied by a prior call to<i><a href="ungetc.html">ungetc()</a></i>or<i><a href="ungetwc.html">ungetwc()</a></i>.</blockquote><h4><a name = "tag_000_005_071"> </a>RETURN VALUE</h4><blockquote>Upon successful completion the<i>fgetwc()</i>function returns the wide-character code of the character read from the inputstream pointed to by<i>stream</i>converted to a type<b>wint_t</b>.If the streamis at end-of-file, the end-of-file indicator forthe stream is set and<i>fgetwc()</i>returns WEOF.If a read error occurs, the error indicator for the stream is set,<i>fgetwc()</i>returns WEOF and sets<i>errno</i>to indicate the error.</blockquote><h4><a name = "tag_000_005_072"> </a>ERRORS</h4><blockquote>The<i>fgetwc()</i>function will fail if data needs to be read and:<dl compact><dt>[EAGAIN]<dd>The O_NONBLOCK flag is set for the file descriptor underlying<i>stream</i>and the process would be delayed in the<i>fgetwc()</i>operation.<dt>[EBADF]<dd>The file descriptor underlying<i>stream</i>is not a valid file descriptor open for reading.<dt>[EINTR]<dd>The read operation was terminated due to the receiptof a signal, and no data was transferred.<dt>[EIO]<dd>A physical I/O error has occurred, orthe process is in a background process group attempting to readfrom its controlling terminal, and either the process is ignoring orblocking the SIGTTIN signal or the process group is orphaned.This error may also be generated for implementation-dependentreasons.<dt>[EOVERFLOW]<dd>The file is a regular file and an attempt was made to read at or beyondthe offset maximum associated with the corresponding stream.</dl><p>The<i>fgetwc()</i>function may fail if:<dl compact><dt>[ENOMEM]<dd>Insufficient storage space is available.<dt>[ENXIO]<dd>A request was made of a non-existent device, or the request wasoutside the capabilities of the device.<dt>[EILSEQ]<dd>The data obtained from the input stream does not form a valid character.</dl></blockquote><h4><a name = "tag_000_005_073"> </a>EXAMPLES</h4><blockquote>None.</blockquote><h4><a name = "tag_000_005_074"> </a>APPLICATION USAGE</h4><blockquote>The<i><a href="ferror.html">ferror()</a></i>or<i><a href="feof.html">feof()</a></i>functions must be used to distinguish betweenan error condition and an end-of-file condition.</blockquote><h4><a name = "tag_000_005_075"> </a>FUTURE DIRECTIONS</h4><blockquote>None.</blockquote><h4><a name = "tag_000_005_076"> </a>SEE ALSO</h4><blockquote><i><a href="feof.html">feof()</a></i>,<i><a href="ferror.html">ferror()</a></i>,<i><a href="fopen.html">fopen()</a></i>,<i><a href="stdio.h.html"><stdio.h></a></i>,<i><a href="wchar.h.html"><wchar.h></a></i>.</blockquote><h4>DERIVATION</h4><blockquote>Derived from the MSE working draft.</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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