이중포인터를 사용하여 문자열의 배열을 동적으로 할당하고 해제하는 예제.

arr_of_string.c

#include <stdio.h>
#include <stdlib.h> // for calloc()
#include <string.h> // for strcpy() . not necessary because compiler will automatically include string.h. (with warning)

#define MAXNUM 50

int main(void)
{
	char **arrs; // declare arrs with pointer of char pointer.
	arrs = (char**)calloc(MAXNUM, sizeof(char*)); // allocate 50*4bytes to arrs. it holds address of each string array.
	int i;
	for(i=0;i<MAXNUM;i++) {
		arrs[i] = (char*)calloc(sizeof(char),13); // allocate memory of each string
		strcpy(arrs[i],"TEST PROGRAM");
	}

	i = 0;
	while(i<MAXNUM) { // print and free.
		printf("%x : %s", (int)arrs[i], arrs[i]);
		free(arrs[i]);
	}
	free(arrs[i]); // free arrs.
	return 0;
}