strtok_r(3) [netbsd man page]

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 * restrict str, const char * restrict sep);

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

DESCRIPTION

     The strtok() function is used to isolate sequential tokens in a nul-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 strtok() function returns a pointer to the beginning of each subsequent token in the string, after replacing the separator character
     itself with a NUL character.  Separator characters at the beginning of the string or at the continuation point are skipped so that zero
     length tokens are not returned.  When no more tokens remain, a null pointer is returned.

     The strtok_r() function implements the functionality of strtok() but is passed an additional argument, lasts, which points to a user-provided
     pointer which is used by strtok_r() to store state which needs to be kept between calls to scan the same string; unlike strtok(), it is not
     necessary to limit tokenizing to a single string at a time when using strtok_r().

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];
	   char *last;
	   int i = 0;

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

	   for ((p = strtok_r(s, " ", &last)); p;
	       (p = strtok_r(NULL, " ", &last)), i++) {
		   if (i < MAXTOKENS - 1)
			   tokens[i] = p;
	   }
	   tokens[i] = NULL;

     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

     index(3), memchr(3), rindex(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 C89'').  The strtok_r() function conforms to IEEE Std 1003.1c-1995 (``POSIX.1'').

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
								  August 11, 2002							       BSD

Check Out this Related Man Page

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

NAME

       strtok, strtok_r - extract tokens from strings

SYNOPSIS

       #include <string.h>

       char *strtok(char *s, const char *delim);

       char *strtok_r(char *s, const char *delim, char **ptrptr);

DESCRIPTION

       A `token' is a nonempty string of characters not occurring in the string delim, followed by  or by a character occurring in delim.

       The strtok() function can be used to parse the string s into tokens. The first call to strtok() should have s as its first argument. Subse-
       quent calls should have the first argument set to NULL. Each call returns a pointer to the next token, or NULL  when  no  more  tokens  are
       found.

       If  a  token ends with a delimiter, this delimiting character is overwritten with a  and a pointer to the next character is saved for the
       next call to strtok().  The delimiter string delim may be different for each call.

       The strtok_r() function is a reentrant version of the strtok() function, which instead of using its own static buffer, requires	a  pointer
       to a user allocated char*. This pointer, the ptrptr parameter, must be the same while parsing the same string.

BUGS

       Never use these functions. If you do, note that:

	      These functions modify their first argument.

	      These functions cannot be used on constant strings.

	      The identity of the delimiting character is lost.

	      The strtok() function uses a static buffer while parsing, so it's not thread safe. Use strtok_r() if this matters to you.

RETURN VALUE

       The strtok() function returns a pointer to the next token, or NULL if there are no more tokens.

CONFORMING TO

       strtok()
	      SVID 3, POSIX, BSD 4.3, ISO 9899

       strtok_r()
	      POSIX.1c

SEE ALSO

       index(3), memchr(3), rindex(3), strchr(3), strpbrk(3), strsep(3), strspn(3), strstr(3)

GNU
								    2000-02-13								 STRTOK(3)

Linux and UNIX Man Pages

strtok_r(3) [netbsd man page]

Check Out this Related Man Page