STRTOK(3)                 OpenBSD Programmer's Manual                STRTOK(3)

NAME
     strtok - string token operations



SYNOPSIS
     #include <string.h>

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

DESCRIPTION
     This interface is obsoleted by strsep(3).

     The strtok() function is used to isolate sequential tokens in a null-ter-
     minated 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 strtok() function returns a pointer to the beginning of each subse-
     quent token in the string, after replacing the separator character itself
     with an ASCII NUL character.  When no more tokens remain, a null pointer
     is returned.

     Since strtok() modifies the string, str should not point to an area in
     the initialized data segment.

EXAMPLES
     The following will construct an array of pointers to each individual word
     in the string s:

           #define MAXTOKENS       128

           char s[512], *p, *tokens[MAXTOKENS];
           int i = 0;

           snprintf(s, sizeof(s), "cat dog horse cow");

           for ((p = strtok(s, " ")); p; (p = strtok(NULL, " ")), i++) {
               if (i < MAXTOKENS - 1)
                   tokens[i] = p;
           }
           tokens[i] = '\0';

     That is, tokens[0] will point to "cat", tokens[1] will point to "dog",
     tokens[2] will point to "horse", and tokens[3] will point to "cow".

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

STANDARDS
     The strtok() function conforms to ANSI X3.159-1989 (``ANSI C'').

BUGS
     There is no way to get tokens from multiple strings simultaneously.

     The System V strtok(), if handed a string containing only delimiter char-
     acters, 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.


OpenBSD 2.6                      June 29, 1991                               1