254 lines
6.4 KiB
HTML
254 lines
6.4 KiB
HTML
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
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<title>pause()--Suspend Process Until Signal Received</title>
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<!-- Begin Header Records ========================================== -->
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<!-- UNIX5 SCRIPT J converted by B2H R4.1 (346) (CMS) by V2KEA304 -->
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<!-- at RCHVMW2 on 17 Feb 1999 at 11:05:09 -->
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<!-- Edited by Kersten Feb 02 -->
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<!--End Header Records -->
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<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
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</head>
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<body>
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<a name="Top_Of_Page"></a>
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<!-- Java sync-link -->
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<script type="text/javascript" language="Javascript" src="../rzahg/synch.js">
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</script>
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<h2>pause()--Suspend Process Until Signal Received</h2>
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<div class="box" style="width: 60%;">
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<br>
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Syntax<br>
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<pre>
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#include <unistd.h>
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int pause( void );
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</pre>
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<br>
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Service Program Name: QPOSSRV1<br>
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<!-- iddvc RMBR -->
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<br>
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Default Public Authority: *USE<br>
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<!-- iddvc RMBR -->
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<br>
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Threadsafe: Yes<br>
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<!-- iddvc RMBR -->
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<br>
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</div>
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<p>The <strong>pause()</strong> function suspends processing of the calling
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thread. The thread does not resume until a signal is delivered whose action is
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to call a signal-catching function, end the request, or terminate the process.
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Some signals can be blocked by the thread's <em>signal mask</em>. See <a href=
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"sigpmsk.htm">sigprocmask()--Examine and Change Blocked Signals</a> for
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details.</p>
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<p>If an incoming unblocked signal has an action of end the request or
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terminate the process, <strong>pause()</strong> never returns to the caller. If
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an incoming signal is handled by a signal-catching function,
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<strong>pause()</strong> returns after the signal-catching function
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returns.</p>
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<br>
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<!-- Please NOTE: DO NOT DELETE THIS SECTION if this API has no authorities and locks. -->
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<!-- Instead, use the commented out coding below to indicate NONE. -->
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<h3>Authorities and Locks</h3>
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<!-- Use this if there are no authorities and locks. -->
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<p>None.</p>
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<br>
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<h3>Parameters</h3>
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<p>None.</p>
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<br>
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<h3>Return Value</h3>
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<p>There is no return value to indicate successful completion.</p>
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<br>
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<h3>Error Conditions</h3>
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<p>If <strong>pause()</strong> returns, <em>errno</em> indicates the
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following:</p>
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<dl>
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<dt><em>-1</em></dt>
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<dd><p><strong>pause()</strong> was not successful. The <em>errno</em> variable is
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set to indicate the reason.</p> </dd>
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<dt><em>[EINTR]</em></dt>
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<dd><p>Interrupted function call.</p>
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<p>A signal was received and handled by a signal-catching function that
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returned. </p>
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</dd>
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<dt><em>[ENOTSIGINIT]</em></dt>
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<dd><p>Process not enabled for signals.</p>
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<p>An attempt was made to call a signal function under one of the following
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conditions:</p>
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<ul>
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<li>The signal function is being called for a process that is not enabled for
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asynchronous signals.</li>
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<li>The signal function is being called when the system signal controls have
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not been initialized.<br>
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</li>
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</ul>
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<br></dd>
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<dt><em>[EWOULDBLOCK]</em></dt>
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<dd>Operation would have caused the process to be suspended.
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The current thread state would prevent the signal function from completing.
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</dd>
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</dl>
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<br>
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<h3>Usage Notes</h3>
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<p>The <strong>pause()</strong> function enables a process for signals if the
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process is not already enabled for signals. For details, see <a href=
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"sigesig.htm">Qp0sEnableSignals()--Enable Process for Signals</a>. If the
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system has not been enabled for signals, <strong>pause()</strong> is not
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successful, and an [ENOTSIGINIT] error is returned.</p>
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<br>
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<h3>Related Information</h3>
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<ul>
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<li>The <<strong>unistd.h</strong>> file (see <a href="unix13.htm">Header
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Files for UNIX-Type Functions</a>)<br>
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<br>
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</li>
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<li><a href="sigalarm.htm">alarm()</a>--Set Schedule for Alarm Signal<br>
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<br>
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</li>
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<li><a href="sigkill.htm">kill()</a>--Send Signal to Process or Group of
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Processes<br>
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<br>
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</li>
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<li><a href="sigdsig.htm">Qp0sDisableSignals()</a>--Disable Process for
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Signals<br>
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<br>
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</li>
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<li><a href="sigesig.htm">Qp0sEnableSignals()</a>--Enable Process for
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Signals<br>
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<br>
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</li>
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<li><a href="sigpmsk.htm">sigprocmask()</a>--Examine and Change Blocked
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Signals<br>
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<br>
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</li>
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<li><a href="sigsusp.htm">sigsuspend()</a>--Wait for Signal<br>
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<br>
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</li>
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<li><a href="sigtwait.htm">sigtimedwait()</a>--Synchronously Accept a Signal for
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Interval of Time<br>
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<br>
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</li>
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<li><a href="sigwait.htm">sigwait()</a>--Synchronously Accept a Signal<br>
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<br>
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</li>
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<li><a href="sigwaiti.htm">sigwaitinfo()</a>--Synchronously Accept a Signal and
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Signal Data<br>
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<br>
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</li>
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<li><a href="sigsleep.htm">sleep()</a>--Suspend Processing for Interval of
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Time</li>
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</ul>
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<br>
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<h3>Example</h3>
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<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
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for information pertaining to code examples.</p>
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<p>The following example suspends processing using the <strong>pause()</strong>
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function and determines the current time:</p>
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<pre>
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#include <unistd.h>
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#include <signal.h>
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#include <stdio.h>
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#include <time.h>
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void catcher( int sig ) {
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printf( "Signal catcher called for signal %d\n", sig );
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}
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void timestamp( char *str ) {
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time_t t;
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time(&t);
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printf( "The time %s is %s\n", str, ctime(&t) );
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}
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int main( int argc, char *argv[] ) {
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struct sigaction sigact;
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sigemptyset( &sigact.sa_mask );
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sigact.sa_flags = 0;
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sigact.sa_handler = catcher;
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sigaction( SIGALRM, &sigact, NULL );
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alarm( 10 );
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timestamp( "before pause" );
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pause();
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timestamp( "after pause" );
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return( 0 );
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}
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</pre>
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<br>
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<h3>Output:</h3>
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<pre>
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The time before pause is Sun Jan 22 11:09:08 1995
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Signal catcher called for signal 14
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The time after pause is Sun Jan 22 11:09:18 1995
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</pre>
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<br>
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<hr>
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API introduced: V3R6
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<hr>
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<center><table cellpadding="2" cellspacing="2">
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<tr align="center">
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<td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href=
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"unix.htm">UNIX-Type APIs</a> | <a href="aplist.htm">APIs by category</a> </td>
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</tr>
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</table>
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</center></body>
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</html>
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