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来自「IEEE 1003.1-2003, Single Unix Specificat」· HTML 代码 · 共 201 行
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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>symlink</title></head><body bgcolor="white"><basefont size="3"> <a name="symlink"></a> <a name="tag_03_753"></a><!-- symlink --> <!--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_753_01"></a>NAME</h4><blockquote>symlink - make a symbolic link to a file</blockquote><h4><a name="tag_03_753_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><p><code><tt>#include <<a href="../basedefs/unistd.h.html">unistd.h</a>><br><br> int symlink(const char *</tt><i>path1</i><tt>, const char *</tt><i>path2</i><tt>);<br></tt></code></p></blockquote><h4><a name="tag_03_753_03"></a>DESCRIPTION</h4><blockquote><p>The <i>symlink</i>() function shall create a symbolic link called <i>path2</i> that contains the string pointed to by<i>path1</i> ( <i>path2</i> is the name of the symbolic link created, <i>path1</i> is the string contained in the symboliclink).</p><p>The string pointed to by <i>path1</i> shall be treated only as a character string and shall not be validated as a pathname.</p><p>If the <i>symlink</i>() function fails for any reason other than [EIO], any file named by <i>path2</i> shall be unaffected.</p></blockquote><h4><a name="tag_03_753_04"></a>RETURN VALUE</h4><blockquote><p>Upon successful completion, <i>symlink</i>() shall return 0; otherwise, it shall return -1 and set <i>errno</i> to indicate theerror.</p></blockquote><h4><a name="tag_03_753_05"></a>ERRORS</h4><blockquote><p>The <i>symlink</i>() function shall fail if:</p><dl compact><dt>[EACCES]</dt><dd>Write permission is denied in the directory where the symbolic link is being created, or search permission is denied for acomponent of the path prefix of <i>path2</i>.</dd><dt>[EEXIST]</dt><dd>The <i>path2</i> argument names an existing file or symbolic link.</dd><dt>[EIO]</dt><dd>An I/O error occurs while reading from or writing to the file system.</dd><dt>[ELOOP]</dt><dd>A loop exists in symbolic links encountered during resolution of the <i>path2</i> argument.</dd><dt>[ENAMETOOLONG]</dt><dd>The length of the <i>path2</i> argument exceeds {PATH_MAX} or a pathname component is longer than {NAME_MAX} or the length of the<i>path1</i> argument is longer than {SYMLINK_MAX}.</dd><dt>[ENOENT]</dt><dd>A component of <i>path2</i> does not name an existing file or <i>path2</i> is an empty string.</dd><dt>[ENOSPC]</dt><dd>The directory in which the entry for the new symbolic link is being placed cannot be extended because no space is left on thefile system containing the directory, or the new symbolic link cannot be created because no space is left on the file system whichshall contain the link, or the file system is out of file-allocation resources.</dd><dt>[ENOTDIR]</dt><dd>A component of the path prefix of <i>path2</i> is not a directory.</dd><dt>[EROFS]</dt><dd>The new symbolic link would reside on a read-only file system.</dd></dl><p>The <i>symlink</i>() function may fail if:</p><dl compact><dt>[ELOOP]</dt><dd>More than {SYMLOOP_MAX} symbolic links were encountered during resolution of the <i>path2</i> argument.</dd><dt>[ENAMETOOLONG]</dt><dd>As a result of encountering a symbolic link in resolution of the <i>path2</i> argument, the length of the substituted pathnamestring exceeded {PATH_MAX} bytes (including the terminating null byte), or the length of the string pointed to by <i>path1</i>exceeded {SYMLINK_MAX}.</dd></dl></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_753_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_753_07"></a>APPLICATION USAGE</h4><blockquote><p>Like a hard link, a symbolic link allows a file to have multiple logical names. The presence of a hard link guarantees theexistence of a file, even after the original name has been removed. A symbolic link provides no such assurance; in fact, the filenamed by the <i>path1</i> argument need not exist when the link is created. A symbolic link can cross file system boundaries.</p><p>Normal permission checks are made on each component of the symbolic link pathname during its resolution.</p></blockquote><h4><a name="tag_03_753_08"></a>RATIONALE</h4><blockquote><p>Since IEEE Std 1003.1-2001 does not require any association of file times with symbolic links, there is no requirementthat file times be updated by <i>symlink</i>().</p></blockquote><h4><a name="tag_03_753_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_753_10"></a>SEE ALSO</h4><blockquote><p><a href="lchown.html"><i>lchown</i>()</a> , <a href="link.html"><i>link</i>()</a> , <a href="lstat.html"><i>lstat</i>()</a> , <ahref="open.html"><i>open</i>()</a> , <a href="readlink.html"><i>readlink</i>()</a> , <a href="unlink.html"><i>unlink</i>()</a> ,the Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/unistd.h.html"><i><unistd.h></i></a></p></blockquote><h4><a name="tag_03_753_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 4, Version 2.</p></blockquote><h4><a name="tag_03_753_12"></a>Issue 5</h4><blockquote><p>Moved from X/OPEN UNIX extension to BASE.</p></blockquote><h4><a name="tag_03_753_13"></a>Issue 6</h4><blockquote><p>The following changes were made to align with the IEEE P1003.1a draft standard:</p><ul><li><p>The DESCRIPTION text is updated.</p></li><li><p>The [ELOOP] optional error condition is added.</p></li></ul></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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