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strtok, strtok_r - string tokens

 

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-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 fur‐
      ther 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 con‐
      texts:
 
      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\n", word, phrase);
          }
      }
      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 C89”).
 

AUTHORS

      Wes Peters, Softweyr LLC: 〈wes@softweyr.com〉
 
      Based on the FreeBSD 3.0 implementation.
 

BUGS

      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 start‐
      ing point, such a sequence of calls would always return NULL.
 

Sections

Based on BSD UNIX
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