[321程式] C版的explode() 函式–explode() in C

/*

* explode function like in PHP (realloc version)

* completed in 2012/3/21

* since 2012/3/21

*/

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

 

char **explode(const char *del, const char *src, int *size);

 

int main(int argc, char *argv[]) {

     char *str = "We will we will rock you!";

     char **new_str;

     int i, len;

 

     printf("The original str: %s\n", str);

     new_str = explode("* ", str, &len);

     printf("The length: %d\n", len);

     printf("After explode:\n");

     for(i = 0; i < len; i++){

         printf("%s\n", new_str[i]);

     }

 

     system("pause");

 

     return 0;

}

 

char **explode(const char *del, const char *src, int *size) {

     int i = 0;

     int idx_del;

     int idx_src = 0;

     int num_token = 0;

     int last_pos = 0;

     char **des = NULL;

 

     // get the token and doing explode

     while(*(src+idx_src) != '\0') {

         idx_del = 0;

         while(*(del+idx_del) != '\0') {

              if(*(src+idx_src) == *(del+idx_del)){

                  // increase the num of token

                  num_token++;

                  // re-allocate the space for 'des'

                  des = (char**)realloc(des, (num_token)*sizeof(char*));

                  // allocate in real time for the new string

                  des[i] = (char*)malloc((idx_src-last_pos+1)*sizeof(char));

                  // put the 'end of string' in the last item

                  des[i][idx_src-last_pos] = '\0';

                  // copy the specific section to be the new string

                  strncpy(des[i++], src+last_pos, idx_src-last_pos);

                  // record the position for the next new string

                  last_pos = idx_src+1;

                  // exit the current loop

                  break;

              }

              idx_del++;

         }

         idx_src++;

     }

     num_token += 1;

     // assign the num of token to the variable from outside

     *size = num_token;

 

     // don't forget the last one if there is

     des[num_token-1] = (char*)malloc((idx_src-last_pos+1)*sizeof(char));

     des[num_token-1][idx_src-last_pos] = '\0';

     strncpy(des[num_token-1], src+last_pos, idx_src-last_pos);

 

     return des;

}