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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>tcgetpgrp</title></head><body bgcolor="white"><basefont size="3"> <a name="tcgetpgrp"></a> <a name="tag_03_765"></a><!-- tcgetpgrp --> <!--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_765_01"></a>NAME</h4><blockquote>tcgetpgrp - get the foreground process group ID</blockquote><h4><a name="tag_03_765_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><p><code><tt>#include <<a href="../basedefs/unistd.h.html">unistd.h</a>><br><br> pid_t tcgetpgrp(int</tt> <i>fildes</i><tt>);<br></tt></code></p></blockquote><h4><a name="tag_03_765_03"></a>DESCRIPTION</h4><blockquote><p>The <i>tcgetpgrp</i>() function shall return the value of the process group ID of the foreground process group associated withthe terminal.</p><p>If there is no foreground process group, <i>tcgetpgrp</i>() shall return a value greater than 1 that does not match the processgroup ID of any existing process group.</p><p>The <i>tcgetpgrp</i>() function is allowed from a process that is a member of a background process group; however, theinformation may be subsequently changed by a process that is a member of a foreground process group.</p></blockquote><h4><a name="tag_03_765_04"></a>RETURN VALUE</h4><blockquote><p>Upon successful completion, <i>tcgetpgrp</i>() shall return the value of the process group ID of the foreground processassociated with the terminal. Otherwise, -1 shall be returned and <i>errno</i> set to indicate the error.</p></blockquote><h4><a name="tag_03_765_05"></a>ERRORS</h4><blockquote><p>The <i>tcgetpgrp</i>() function shall fail if:</p><dl compact><dt>[EBADF]</dt><dd>The <i>fildes</i> argument is not a valid file descriptor.</dd><dt>[ENOTTY]</dt><dd>The calling process does not have a controlling terminal, or the file is not the controlling terminal.</dd></dl></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_765_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_765_07"></a>APPLICATION USAGE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_765_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_765_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_765_10"></a>SEE ALSO</h4><blockquote><p><a href="setsid.html"><i>setsid</i>()</a> , <a href="setpgid.html"><i>setpgid</i>()</a> , <a href="tcsetpgrp.html"><i>tcsetpgrp</i>()</a> , the Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/sys/types.h.html"><i><sys/types.h></i></a>, <a href="../basedefs/unistd.h.html"><i><unistd.h></i></a></p></blockquote><h4><a name="tag_03_765_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 3. Included for alignment with the POSIX.1-1988 standard.</p></blockquote><h4><a name="tag_03_765_12"></a>Issue 6</h4><blockquote><p>In the SYNOPSIS, the optional include of the <a href="../basedefs/sys/types.h.html"><i><sys/types.h></i></a> header isremoved.</p><p>The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:</p><ul><li><p>The requirement to include <a href="../basedefs/sys/types.h.html"><i><sys/types.h></i></a> has been removed. Although <ahref="../basedefs/sys/types.h.html"><i><sys/types.h></i></a> was required for conforming implementations of previous POSIXspecifications, it was not required for UNIX applications.</p></li><li><p>In the DESCRIPTION, text previously conditional on support for _POSIX_JOB_CONTROL is now mandatory. This is a FIPSrequirement.</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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