str_locword

/*
  avp 2014 str_locword()

  little function to locate word in char[] string
*/


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

// Returns start of n'th word in str[] and it's length (in *wlen)
//  or pointer to end of string and  length == 0
char *str_locword (const char *str, int nword, int *wlen);

static inline int
skipword (const char *w)
{
  int l = 0;
  while (w[l] && !isspace(w[l++]));

  return w[l] ? --l : l;
}


char *
str_locword (const char *str, int nword, int *wlen)
{
  *wlen = 0;
  do {
    str += *wlen;
    while (isspace(*str))
      str++;
    *wlen = skipword(str);
  } while (*wlen && nword--);

  return (char *)str;
}

#if TEST
#define FGETS(prompt,str,size,file)     \
  (fputs((prompt), stdout), fflush(stdout), \
   fgets((str), (size), file))

int
main (int ac, char *av[])
{
  char str[1000];

  while (FGETS("Enter str: ", str, 1000, stdin)) {
    str[strlen(str) - 1] = 0;
    int wsz, nw;
    char *w;
    if (sscanf(str, "%d", &nw) == 1) {
      printf ("word %d :", nw);
      w = str_locword(str, nw, &wsz);
      char word[wsz + 1];
      strncpy(word, w, wsz);
      word[wsz] = 0;
      printf (" [%s]\n", word);
    }
  }

  return puts("\nend") == EOF;
}

#endif