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535 lines
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HTML
535 lines
14 KiB
HTML
4 years ago
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>strerror (The Red Hat newlib C Library)</title>
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<meta name="description" content="strerror (The Red Hat newlib C Library)">
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<meta name="keywords" content="strerror (The Red Hat newlib C Library)">
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<link href="index.html#Top" rel="start" title="Top">
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<link href="Document-Index.html#Document-Index" rel="index" title="Document Index">
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<link href="Document-Index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="Strings.html#Strings" rel="up" title="Strings">
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<link href="strerror_005fr.html#strerror_005fr" rel="next" title="strerror_r">
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<link href="strcspn.html#strcspn" rel="prev" title="strcspn">
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<style type="text/css">
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</head>
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<body lang="en">
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<a name="strerror"></a>
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<div class="header">
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<p>
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Next: <a href="strerror_005fr.html#strerror_005fr" accesskey="n" rel="next">strerror_r</a>, Previous: <a href="strcspn.html#strcspn" accesskey="p" rel="prev">strcspn</a>, Up: <a href="Strings.html#Strings" accesskey="u" rel="up">Strings</a> [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
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</div>
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<hr>
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<a name="strerror_002c-strerror_005fl_002d_002d_002dconvert-error-number-to-string"></a>
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<h3 class="section">5.27 <code>strerror</code>, <code>strerror_l</code>—convert error number to string</h3>
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<a name="index-strerror"></a>
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<a name="index-strerror_005fl"></a>
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<p><strong>Synopsis</strong>
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</p><div class="example">
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<pre class="example">#include <string.h>
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char *strerror(int <var>errnum</var>);
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char *strerror_l(int <var>errnum</var>, locale_t <var>locale</var>);
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char *_strerror_r(struct _reent <var>ptr</var>, int <var>errnum</var>,
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int <var>internal</var>, int *<var>error</var>);
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</pre></div>
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<p><strong>Description</strong><br>
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<code>strerror</code> converts the error number <var>errnum</var> into a
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string. The value of <var>errnum</var> is usually a copy of <code>errno</code>.
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If <code>errnum</code> is not a known error number, the result points to an
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empty string.
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</p>
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<p><code>strerror_l</code> is like <code>strerror</code> but creates a string in a format
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as expected in locale <var>locale</var>. If <var>locale</var> is LC_GLOBAL_LOCALE or
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not a valid locale object, the behaviour is undefined.
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</p>
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<p>This implementation of <code>strerror</code> prints out the following strings
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for each of the values defined in ‘<code>errno.h</code>’:
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</p>
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<dl compact="compact">
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<dt><code>0</code></dt>
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<dd><p>Success
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</p>
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</dd>
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<dt><code>E2BIG</code></dt>
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<dd><p>Arg list too long
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</p>
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</dd>
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<dt><code>EACCES</code></dt>
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<dd><p>Permission denied
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</p>
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</dd>
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<dt><code>EADDRINUSE</code></dt>
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<dd><p>Address already in use
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</p>
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</dd>
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<dt><code>EADDRNOTAVAIL</code></dt>
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<dd><p>Address not available
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</p>
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</dd>
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<dt><code>EADV</code></dt>
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<dd><p>Advertise error
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</p>
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</dd>
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<dt><code>EAFNOSUPPORT</code></dt>
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<dd><p>Address family not supported by protocol family
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</p>
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</dd>
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<dt><code>EAGAIN</code></dt>
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<dd><p>No more processes
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</p>
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</dd>
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<dt><code>EALREADY</code></dt>
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<dd><p>Socket already connected
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</p>
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</dd>
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<dt><code>EBADF</code></dt>
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<dd><p>Bad file number
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</p>
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</dd>
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<dt><code>EBADMSG</code></dt>
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<dd><p>Bad message
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</p>
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</dd>
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<dt><code>EBUSY</code></dt>
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<dd><p>Device or resource busy
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</p>
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</dd>
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<dt><code>ECANCELED</code></dt>
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<dd><p>Operation canceled
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</p>
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</dd>
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<dt><code>ECHILD</code></dt>
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<dd><p>No children
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</p>
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</dd>
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<dt><code>ECOMM</code></dt>
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<dd><p>Communication error
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</p>
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</dd>
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<dt><code>ECONNABORTED</code></dt>
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<dd><p>Software caused connection abort
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</p>
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</dd>
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<dt><code>ECONNREFUSED</code></dt>
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<dd><p>Connection refused
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</p>
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</dd>
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<dt><code>ECONNRESET</code></dt>
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<dd><p>Connection reset by peer
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</p>
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</dd>
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<dt><code>EDEADLK</code></dt>
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<dd><p>Deadlock
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</p>
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</dd>
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<dt><code>EDESTADDRREQ</code></dt>
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<dd><p>Destination address required
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</p>
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</dd>
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<dt><code>EEXIST</code></dt>
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<dd><p>File exists
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</p>
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</dd>
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<dt><code>EDOM</code></dt>
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<dd><p>Mathematics argument out of domain of function
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</p>
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</dd>
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<dt><code>EFAULT</code></dt>
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<dd><p>Bad address
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</p>
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</dd>
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<dt><code>EFBIG</code></dt>
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<dd><p>File too large
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</p>
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</dd>
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<dt><code>EHOSTDOWN</code></dt>
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<dd><p>Host is down
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</p>
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</dd>
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<dt><code>EHOSTUNREACH</code></dt>
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<dd><p>Host is unreachable
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</p>
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</dd>
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<dt><code>EIDRM</code></dt>
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<dd><p>Identifier removed
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</p>
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</dd>
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<dt><code>EILSEQ</code></dt>
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<dd><p>Illegal byte sequence
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</p>
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</dd>
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<dt><code>EINPROGRESS</code></dt>
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<dd><p>Connection already in progress
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</p>
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</dd>
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<dt><code>EINTR</code></dt>
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<dd><p>Interrupted system call
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</p>
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</dd>
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<dt><code>EINVAL</code></dt>
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<dd><p>Invalid argument
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</p>
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</dd>
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<dt><code>EIO</code></dt>
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<dd><p>I/O error
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</p>
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</dd>
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<dt><code>EISCONN</code></dt>
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<dd><p>Socket is already connected
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</p>
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</dd>
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<dt><code>EISDIR</code></dt>
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<dd><p>Is a directory
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</p>
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</dd>
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<dt><code>ELIBACC</code></dt>
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<dd><p>Cannot access a needed shared library
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</p>
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</dd>
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<dt><code>ELIBBAD</code></dt>
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<dd><p>Accessing a corrupted shared library
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</p>
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</dd>
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<dt><code>ELIBEXEC</code></dt>
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<dd><p>Cannot exec a shared library directly
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</p>
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</dd>
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<dt><code>ELIBMAX</code></dt>
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<dd><p>Attempting to link in more shared libraries than system limit
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</p>
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</dd>
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<dt><code>ELIBSCN</code></dt>
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<dd><p><code>.lib</code> section in a.out corrupted
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</p>
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</dd>
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<dt><code>EMFILE</code></dt>
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<dd><p>File descriptor value too large
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</p>
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</dd>
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<dt><code>EMLINK</code></dt>
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<dd><p>Too many links
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</p>
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</dd>
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<dt><code>EMSGSIZE</code></dt>
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<dd><p>Message too long
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</p>
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</dd>
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<dt><code>EMULTIHOP</code></dt>
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<dd><p>Multihop attempted
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</p>
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</dd>
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<dt><code>ENAMETOOLONG</code></dt>
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<dd><p>File or path name too long
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</p>
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</dd>
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<dt><code>ENETDOWN</code></dt>
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<dd><p>Network interface is not configured
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</p>
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</dd>
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<dt><code>ENETRESET</code></dt>
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<dd><p>Connection aborted by network
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</p>
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</dd>
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<dt><code>ENETUNREACH</code></dt>
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<dd><p>Network is unreachable
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</p>
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</dd>
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<dt><code>ENFILE</code></dt>
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<dd><p>Too many open files in system
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</p>
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</dd>
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<dt><code>ENOBUFS</code></dt>
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<dd><p>No buffer space available
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</p>
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</dd>
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<dt><code>ENODATA</code></dt>
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<dd><p>No data
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</p>
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</dd>
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<dt><code>ENODEV</code></dt>
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<dd><p>No such device
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</p>
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</dd>
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<dt><code>ENOENT</code></dt>
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<dd><p>No such file or directory
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</p>
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</dd>
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<dt><code>ENOEXEC</code></dt>
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<dd><p>Exec format error
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</p>
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</dd>
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<dt><code>ENOLCK</code></dt>
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<dd><p>No lock
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</p>
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</dd>
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<dt><code>ENOLINK</code></dt>
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<dd><p>Virtual circuit is gone
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</p>
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</dd>
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<dt><code>ENOMEM</code></dt>
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<dd><p>Not enough space
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</p>
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</dd>
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<dt><code>ENOMSG</code></dt>
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<dd><p>No message of desired type
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</p>
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</dd>
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<dt><code>ENONET</code></dt>
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<dd><p>Machine is not on the network
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</p>
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</dd>
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<dt><code>ENOPKG</code></dt>
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<dd><p>No package
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</p>
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</dd>
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<dt><code>ENOPROTOOPT</code></dt>
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<dd><p>Protocol not available
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</p>
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</dd>
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<dt><code>ENOSPC</code></dt>
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<dd><p>No space left on device
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</p>
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</dd>
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<dt><code>ENOSR</code></dt>
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<dd><p>No stream resources
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</p>
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</dd>
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<dt><code>ENOSTR</code></dt>
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<dd><p>Not a stream
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</p>
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</dd>
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<dt><code>ENOSYS</code></dt>
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<dd><p>Function not implemented
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</p>
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</dd>
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<dt><code>ENOTBLK</code></dt>
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<dd><p>Block device required
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</p>
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</dd>
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<dt><code>ENOTCONN</code></dt>
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<dd><p>Socket is not connected
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</p>
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</dd>
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<dt><code>ENOTDIR</code></dt>
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<dd><p>Not a directory
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</p>
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</dd>
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<dt><code>ENOTEMPTY</code></dt>
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<dd><p>Directory not empty
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</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ENOTRECOVERABLE</code></dt>
|
||
|
|
<dd><p>State not recoverable
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ENOTSOCK</code></dt>
|
||
|
|
<dd><p>Socket operation on non-socket
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ENOTSUP</code></dt>
|
||
|
|
<dd><p>Not supported
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ENOTTY</code></dt>
|
||
|
|
<dd><p>Not a character device
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ENXIO</code></dt>
|
||
|
|
<dd><p>No such device or address
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EOPNOTSUPP</code></dt>
|
||
|
|
<dd><p>Operation not supported on socket
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EOVERFLOW</code></dt>
|
||
|
|
<dd><p>Value too large for defined data type
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EOWNERDEAD</code></dt>
|
||
|
|
<dd><p>Previous owner died
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EPERM</code></dt>
|
||
|
|
<dd><p>Not owner
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EPIPE</code></dt>
|
||
|
|
<dd><p>Broken pipe
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EPROTO</code></dt>
|
||
|
|
<dd><p>Protocol error
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EPROTOTYPE</code></dt>
|
||
|
|
<dd><p>Protocol wrong type for socket
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EPROTONOSUPPORT</code></dt>
|
||
|
|
<dd><p>Unknown protocol
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ERANGE</code></dt>
|
||
|
|
<dd><p>Result too large
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EREMOTE</code></dt>
|
||
|
|
<dd><p>Resource is remote
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EROFS</code></dt>
|
||
|
|
<dd><p>Read-only file system
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ESHUTDOWN</code></dt>
|
||
|
|
<dd><p>Can’t send after socket shutdown
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ESOCKTNOSUPPORT</code></dt>
|
||
|
|
<dd><p>Socket type not supported
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ESPIPE</code></dt>
|
||
|
|
<dd><p>Illegal seek
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ESRCH</code></dt>
|
||
|
|
<dd><p>No such process
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ESRMNT</code></dt>
|
||
|
|
<dd><p>Srmount error
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ESTRPIPE</code></dt>
|
||
|
|
<dd><p>Strings pipe error
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ETIME</code></dt>
|
||
|
|
<dd><p>Stream ioctl timeout
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ETIMEDOUT</code></dt>
|
||
|
|
<dd><p>Connection timed out
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>ETXTBSY</code></dt>
|
||
|
|
<dd><p>Text file busy
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EWOULDBLOCK</code></dt>
|
||
|
|
<dd><p>Operation would block (usually same as EAGAIN)
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
<dt><code>EXDEV</code></dt>
|
||
|
|
<dd><p>Cross-device link
|
||
|
|
</p>
|
||
|
|
</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
|
||
|
|
<p><code>_strerror_r</code> is a reentrant version of the above.
|
||
|
|
</p>
|
||
|
|
<br>
|
||
|
|
<p><strong>Returns</strong><br>
|
||
|
|
This function returns a pointer to a string. Your application must
|
||
|
|
not modify that string.
|
||
|
|
</p>
|
||
|
|
<br>
|
||
|
|
<p><strong>Portability</strong><br>
|
||
|
|
ANSI C requires <code>strerror</code>, but does not specify the strings used
|
||
|
|
for each error number.
|
||
|
|
</p>
|
||
|
|
<p><code>strerror_l</code> is POSIX-1.2008.
|
||
|
|
</p>
|
||
|
|
<p>Although this implementation of <code>strerror</code> is reentrant (depending
|
||
|
|
on <code>_user_strerror</code>), ANSI C declares that subsequent calls to
|
||
|
|
<code>strerror</code> may overwrite the result string; therefore portable
|
||
|
|
code cannot depend on the reentrancy of this subroutine.
|
||
|
|
</p>
|
||
|
|
<p>Although this implementation of <code>strerror</code> guarantees a non-null
|
||
|
|
result with a NUL-terminator, some implementations return <code>NULL</code>
|
||
|
|
on failure. Although POSIX allows <code>strerror</code> to set <code>errno</code>
|
||
|
|
to EINVAL on failure, this implementation does not do so (unless
|
||
|
|
you provide <code>_user_strerror</code>).
|
||
|
|
</p>
|
||
|
|
<p>POSIX recommends that unknown <var>errnum</var> result in a message
|
||
|
|
including that value, however it is not a requirement and this
|
||
|
|
implementation does not provide that information (unless you
|
||
|
|
provide <code>_user_strerror</code>).
|
||
|
|
</p>
|
||
|
|
<p>This implementation of <code>strerror</code> provides for user-defined
|
||
|
|
extensibility. <code>errno.h</code> defines <var>__ELASTERROR</var>, which can be
|
||
|
|
used as a base for user-defined error values. If the user supplies a
|
||
|
|
routine named <code>_user_strerror</code>, and <var>errnum</var> passed to
|
||
|
|
<code>strerror</code> does not match any of the supported values,
|
||
|
|
<code>_user_strerror</code> is called with three arguments. The first is of
|
||
|
|
type <var>int</var>, and is the <var>errnum</var> value unknown to <code>strerror</code>.
|
||
|
|
The second is of type <var>int</var>, and matches the <var>internal</var> argument
|
||
|
|
of <code>_strerror_r</code>; this should be zero if called from <code>strerror</code>
|
||
|
|
and non-zero if called from any other function; <code>_user_strerror</code> can
|
||
|
|
use this information to satisfy the POSIX rule that no other
|
||
|
|
standardized function can overwrite a static buffer reused by
|
||
|
|
<code>strerror</code>. The third is of type <var>int *</var>, and matches the
|
||
|
|
<var>error</var> argument of <code>_strerror_r</code>; if a non-zero value is stored
|
||
|
|
into that location (usually <var>EINVAL</var>), then <code>strerror</code> will set
|
||
|
|
<code>errno</code> to that value, and the XPG variant of <code>strerror_r</code> will
|
||
|
|
return that value instead of zero or <var>ERANGE</var>. <code>_user_strerror</code>
|
||
|
|
returns a <var>char *</var> value; returning <var>NULL</var> implies that the user
|
||
|
|
function did not choose to handle <var>errnum</var>. The default
|
||
|
|
<code>_user_strerror</code> returns <var>NULL</var> for all input values. Note that
|
||
|
|
<code>_user_sterror</code> must be thread-safe, and only denote errors via the
|
||
|
|
third argument rather than modifying <code>errno</code>, if <code>strerror</code> and
|
||
|
|
<code>strerror_r</code> are are to comply with POSIX.
|
||
|
|
</p>
|
||
|
|
<p><code>strerror</code> requires no supporting OS subroutines.
|
||
|
|
</p>
|
||
|
|
<br>
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="strerror_005fr.html#strerror_005fr" accesskey="n" rel="next">strerror_r</a>, Previous: <a href="strcspn.html#strcspn" accesskey="p" rel="prev">strcspn</a>, Up: <a href="Strings.html#Strings" accesskey="u" rel="up">Strings</a> [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|