/*--------------------------------------------------------------------*/
/* teststrtok.c                                                       */
/* Author: Xiaoyan Li                                                 */
/*--------------------------------------------------------------------*/

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

/*--------------------------------------------------------------------*/

/* Demonstrate strtok function.  Return 0, or EXIT_FAILURE if wrong 
input. */

int main(int argc, char *argv[])
{
   char *str, *str_origin, *token;
   int i;
   
   if (argc != 3) {
      fprintf(stderr, "Usage: %s string delim \n",
              argv[0]);
      exit(EXIT_FAILURE);
   }
   if (*argv[1] == '\0'){
     fprintf(stderr, "The string is an empty string!\n");
      exit(EXIT_FAILURE);
   }

   
/* Note: strtok() modifies the first argument. 
Therefore it cannot be used on constant strings.
We do not want to change argv[1]. So we make a copy of it in the 
following code. strtok only returns non-empty strings.
*/

   str = (char *)malloc(strlen(argv[1])+1);
   if (str == NULL){
     fprintf(stderr, "There is not sufficient memory!\n");
     exit(EXIT_FAILURE);
   }

  str_origin =  str; /* points to the memory allocated by malloc!*/

/* 1. demonstrate strtok with a for loop!*/
   printf("Using a for loop!\n");
   strcpy(str, argv[1]);
   for (i = 1; ; i++, str = NULL) {
      token = strtok(str, argv[2]);
      if (token == NULL)
         break;
      printf("%d: %s\n", i, token);      
   }

  
/* 2. demonstrate strtok with a while loop!*/
  printf("Using a while loop!\n");
  str = str_origin;
  strcpy(str, argv[1]);
  i = 1;

  token = strtok(str, argv[2]);
  while(token!=NULL)
  {
      printf("%d: %s\n", i, token);
      i++;

      token = strtok(NULL, argv[2]);
  }

   free(str_origin);





   return 0;
}