1<html lang="en"> 2<head> 3<title>strtok - 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="Strings.html#Strings" title="Strings"> 9<link rel="prev" href="strstr.html#strstr" title="strstr"> 10<link rel="next" href="strupr.html#strupr" title="strupr"> 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="strtok"></a> 29<p> 30Next: <a rel="next" accesskey="n" href="strupr.html#strupr">strupr</a>, 31Previous: <a rel="previous" accesskey="p" href="strstr.html#strstr">strstr</a>, 32Up: <a rel="up" accesskey="u" href="Strings.html#Strings">Strings</a> 33<hr> 34</div> 35 36<h3 class="section">5.38 <code>strtok</code>, <code>strtok_r</code>, <code>strsep</code>—get next token from a string</h3> 37 38<p><a name="index-strtok-406"></a><a name="index-strtok_005fr-407"></a><a name="index-strsep-408"></a><strong>Synopsis</strong> 39<pre class="example"> #include <string.h> 40 char *strtok(char *<var>source</var>, const char *<var>delimiters</var>) 41 char *strtok_r(char *<var>source</var>, const char *<var>delimiters</var>, 42 char **<var>lasts</var>) 43 char *strsep(char **<var>source_ptr</var>, const char *<var>delimiters</var>) 44 45</pre> 46 <p><strong>Description</strong><br> 47The <code>strtok</code> function is used to isolate sequential tokens in a 48null-terminated string, <code>*</code><var>source</var>. These tokens are delimited 49in the string by at least one of the characters in <code>*</code><var>delimiters</var>. 50The first time that <code>strtok</code> is called, <code>*</code><var>source</var> should be 51specified; subsequent calls, wishing to obtain further tokens from 52the same string, should pass a null pointer instead. The separator 53string, <code>*</code><var>delimiters</var>, must be supplied each time and may 54change between calls. 55 56 <p>The <code>strtok</code> function returns a pointer to the beginning of each 57subsequent token in the string, after replacing the separator 58character itself with a null character. When no more tokens remain, 59a null pointer is returned. 60 61 <p>The <code>strtok_r</code> function has the same behavior as <code>strtok</code>, except 62a pointer to placeholder <code>*</code><var>lasts</var> must be supplied by the caller. 63 64 <p>The <code>strsep</code> function is similar in behavior to <code>strtok</code>, except 65a pointer to the string pointer must be supplied <var>source_ptr</var> and 66the function does not skip leading delimiters. When the string starts 67with a delimiter, the delimiter is changed to the null character and 68the empty string is returned. Like <code>strtok_r</code> and <code>strtok</code>, the 69<code>*</code><var>source_ptr</var> is updated to the next character following the 70last delimiter found or NULL if the end of string is reached with 71no more delimiters. 72 73 <p><br> 74<strong>Returns</strong><br> 75<code>strtok</code>, <code>strtok_r</code>, and <code>strsep</code> all return a pointer to the 76next token, or <code>NULL</code> if no more tokens can be found. For 77<code>strsep</code>, a token may be the empty string. 78 79 <p><br> 80<strong>Portability</strong><br> 81<code>strtok</code> is ANSI C. 82<code>strtok_r</code> is POSIX. 83<code>strsep</code> is a BSD extension. 84 85 <p><code>strtok</code>, <code>strtok_r</code>, and <code>strsep</code> require no supporting OS subroutines. 86 87 <p><br> 88 89 </body></html> 90 91