ualarm.html
来自「IEEE 1003.1-2003, Single Unix Specificat」· HTML 代码 · 共 157 行
HTML
157 行
<!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>ualarm</title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="ualarm"></a> <a name="tag_03_796"></a><!-- ualarm --> <!--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_796_01"></a>NAME</h4><blockquote>ualarm - set the interval timer</blockquote><h4><a name="tag_03_796_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><div class="box"><code><tt><sup>[<a href="javascript:open_code('OB XSI')">OB XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border="0"> #include <<a href="../basedefs/unistd.h.html">unistd.h</a>><br><br> useconds_t ualarm(useconds_t</tt> <i>useconds</i><tt>, useconds_t</tt> <i>interval</i><tt>); <img src="../images/opt-end.gif" alt="[Option End]" border="0"></tt></code></div><tt><br></tt></blockquote><h4><a name="tag_03_796_03"></a>DESCRIPTION</h4><blockquote><p>The <i>ualarm</i>() function shall cause the SIGALRM signal to be generated for the calling process after the number of realtimemicroseconds specified by the <i>useconds</i> argument has elapsed. When the <i>interval</i> argument is non-zero, repeated timeoutnotification occurs with a period in microseconds specified by the <i>interval</i> argument. If the notification signal, SIGALRM,is not caught or ignored, the calling process is terminated.</p><p>Implementations may place limitations on the granularity of timer values. For each interval timer, if the requested timer valuerequires a finer granularity than the implementation supports, the actual timer value shall be rounded up to the next supportedvalue.</p><p>Interactions between <i>ualarm</i>() and any of the following are unspecified:</p><blockquote><pre><a href="../functions/alarm.html"><i>alarm</i>()</a><a href="../functions/nanosleep.html"><i>nanosleep</i>()</a><a href="../functions/setitimer.html"><i>setitimer</i>()</a><a href="../functions/timer_create.html"><i>timer_create</i>()</a><a href="../functions/timer_delete.html"><i>timer_delete</i>()</a><a href="../functions/timer_getoverrun.html"><i>timer_getoverrun</i>()</a><a href="../functions/timer_gettime.html"><i>timer_gettime</i>()</a><a href="../functions/timer_settime.html"><i>timer_settime</i>()</a><a href="../functions/sleep.html"><i>sleep</i>()</a></pre></blockquote></blockquote><h4><a name="tag_03_796_04"></a>RETURN VALUE</h4><blockquote><p>The <i>ualarm</i>() function shall return the number of microseconds remaining from the previous <i>ualarm</i>() call. If notimeouts are pending or if <i>ualarm</i>() has not previously been called, <i>ualarm</i>() shall return 0.</p></blockquote><h4><a name="tag_03_796_05"></a>ERRORS</h4><blockquote><p>No errors are defined.</p></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_03_796_06"></a>EXAMPLES</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_796_07"></a>APPLICATION USAGE</h4><blockquote><p>Applications are recommended to use <a href="../functions/nanosleep.html"><i>nanosleep</i>()</a> if the Timers option issupported, or <a href="../functions/setitimer.html"><i>setitimer</i>()</a>, <a href="../functions/timer_create.html"><i>timer_create</i>()</a>, <a href="../functions/timer_delete.html"><i>timer_delete</i>()</a>, <ahref="../functions/timer_getoverrun.html"><i>timer_getoverrun</i>()</a>, <a href="../functions/timer_gettime.html"><i>timer_gettime</i>()</a>, or <a href="../functions/timer_settime.html"><i>timer_settime</i>()</a> instead of this function.</p></blockquote><h4><a name="tag_03_796_08"></a>RATIONALE</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_796_09"></a>FUTURE DIRECTIONS</h4><blockquote><p>None.</p></blockquote><h4><a name="tag_03_796_10"></a>SEE ALSO</h4><blockquote><p><a href="alarm.html"><i>alarm</i>()</a> , <a href="nanosleep.html"><i>nanosleep</i>()</a> , <a href="setitimer.html"><i>setitimer</i>()</a> , <a href="sleep.html"><i>sleep</i>()</a> , <a href="timer_create.html"><i>timer_create</i>()</a> , <a href="timer_delete.html"><i>timer_delete</i>()</a> , <a href="timer_getoverrun.html"><i>timer_getoverrun</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_796_11"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 4, Version 2.</p></blockquote><h4><a name="tag_03_796_12"></a>Issue 5</h4><blockquote><p>Moved from X/OPEN UNIX extension to BASE.</p></blockquote><h4><a name="tag_03_796_13"></a>Issue 6</h4><blockquote><p>This function is marked obsolescent.</p></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
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?