strtos() - extract WORD (token) from str (similar strtok())

// avp 2015 strtos.c get WORD from char[]

#include <stdio.h>
#include <string.h>

/*
 before call: *p -- ptr to start search WORD in delimiters
 after call:  *p -- ptr to next char after word (and *p - word == WORD length)
 returns ptr to WORD or 0
 */
char *
strtos (char **p, const char *delim)
{
  char *word = 0;

  if (*((*p) += strspn(*p, delim))) {
    word = *p;
    (*p) += strcspn(*p, delim);
  }

  return word;
}

char *
strdups (char **p, const char *delim)
{
  char *word = strtos(p, delim);

  return word ? strndup(word, *p - word) : 0;
}


#ifdef TEST
#include <stdlib.h>

static inline char *
strncpyz (char *dst, const char *src, int l)
{
  char *r = dst;

  while (l && (*r++ = *src++))
    l--;
  if (!l)
    *r = 0;

  return dst;
}

int
main (int ac, char *av[])
{
  char *dlim = av[1] ? av[1] : (char *)" \t\r\n";
  char buf[1000], *w, *ep;

  while (fputs("enter: ", stdout), fflush(stdout), fgets(buf, 1000, stdin)) {
#ifdef TDUP
    for (ep = buf; (w = strdups(&ep, dlim));) {
      printf("[%s] ", w);
      free(w);
    }
#else
    char word[1000];
    for (ep = buf; (w = strtos(&ep, dlim));)
      printf("[%s] ", strncpyz(word, w, ep - w));
#endif
    puts("");
  }

  return puts("End") == EOF;
}

#endif