1<html lang="en"> 2<head> 3<title>difftime - Untitled</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Untitled"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Timefns.html#Timefns" title="Timefns"> 9<link rel="prev" href="ctime.html#ctime" title="ctime"> 10<link rel="next" href="gmtime.html#gmtime" title="gmtime"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<meta http-equiv="Content-Style-Type" content="text/css"> 13<style type="text/css"><!-- 14 pre.display { font-family:inherit } 15 pre.format { font-family:inherit } 16 pre.smalldisplay { font-family:inherit; font-size:smaller } 17 pre.smallformat { font-family:inherit; font-size:smaller } 18 pre.smallexample { font-size:smaller } 19 pre.smalllisp { font-size:smaller } 20 span.sc { font-variant:small-caps } 21 span.roman { font-family:serif; font-weight:normal; } 22 span.sansserif { font-family:sans-serif; font-weight:normal; } 23--></style> 24<link rel="stylesheet" type="text/css" href="../cs.css"> 25</head> 26<body> 27<div class="node"> 28<a name="difftime"></a> 29<p> 30Next: <a rel="next" accesskey="n" href="gmtime.html#gmtime">gmtime</a>, 31Previous: <a rel="previous" accesskey="p" href="ctime.html#ctime">ctime</a>, 32Up: <a rel="up" accesskey="u" href="Timefns.html#Timefns">Timefns</a> 33<hr> 34</div> 35 36<h3 class="section">8.4 <code>difftime</code>—subtract two times</h3> 37 38<p><a name="index-difftime-433"></a><strong>Synopsis</strong> 39<pre class="example"> #include <time.h> 40 double difftime(time_t <var>tim1</var>, time_t <var>tim2</var>); 41 42</pre> 43 <p><strong>Description</strong><br> 44Subtracts the two times in the arguments: `<var>tim1</var><code> - </code><var>tim2</var>'. 45 46 <p><br> 47<strong>Returns</strong><br> 48The difference (in seconds) between <var>tim2</var> and <var>tim1</var>, as a <code>double</code>. 49 50 <p><br> 51<strong>Portability</strong><br> 52ANSI C requires <code>difftime</code>, and defines its result to be in seconds 53in all implementations. 54 55 <p><code>difftime</code> requires no supporting OS subroutines. 56 57 <p><br> 58 59 </body></html> 60 61