freebsd man page for strtok

STRTOK(3)						   BSD Library Functions Manual 						 STRTOK(3)

NAME
     strtok, strtok_r -- string tokens

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <string.h>

     char *
     strtok(char *str, const char *sep);

     char *
     strtok_r(char *str, const char *sep, char **last);

DESCRIPTION
     This interface is obsoleted by strsep(3).

     The strtok() function is used to isolate sequential tokens in a null-terminated string, str.  These tokens are separated in the string by at
     least one of the characters in sep.  The first time that strtok() is called, str should be specified; subsequent calls, wishing to obtain
     further tokens from the same string, should pass a null pointer instead.  The separator string, sep, must be supplied each time, and may
     change between calls.

     The implementation will behave as if no library function calls strtok().

     The strtok_r() function is a reentrant version of strtok().  The context pointer last must be provided on each call.  The strtok_r() function
     may also be used to nest two parsing loops within one another, as long as separate context pointers are used.

     The strtok() and strtok_r() functions return a pointer to the beginning of each subsequent token in the string, after replacing the token
     itself with a NUL character.  When no more tokens remain, a null pointer is returned.

EXAMPLES
     The following uses strtok_r() to parse two strings using separate contexts:

     char test[80], blah[80];
     char *sep = "\/:;=-";
     char *word, *phrase, *brkt, *brkb;

     strcpy(test, "This;is.a:test:of=the/string\tokenizer-function.");

     for (word = strtok_r(test, sep, &brkt);
	  word;
	  word = strtok_r(NULL, sep, &brkt))
     {
	 strcpy(blah, "blah:blat:blab:blag");

	 for (phrase = strtok_r(blah, sep, &brkb);
	      phrase;
	      phrase = strtok_r(NULL, sep, &brkb))
	 {
	     printf("So far we're at %s:%s
", word, phrase);
	 }
     }

SEE ALSO
     memchr(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3), strspn(3), strstr(3), wcstok(3)

STANDARDS
     The strtok() function conforms to ISO/IEC 9899:1990 (``ISO C90'').

AUTHORS
     Wes Peters <wes@softweyr.com>, Softweyr LLC

     Based on the FreeBSD 3.0 implementation.

BUGS
     The System V strtok(), if handed a string containing only delimiter characters, will not alter the next starting point, so that a call to
     strtok() with a different (or empty) delimiter string may return a non-NULL value.  Since this implementation always alters the next starting
     point, such a sequence of calls would always return NULL.

BSD
								 November 27, 1998							       BSD