c-free()方法

#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
int main(int argc, char *argv[])
{
    //分配内存空间
   char *ptr = (char *)malloc(10);
   if (NULL == ptr){
       return -1;
   }
   if (argc == 1){
       printf("\n Usage: add a string \n");
   }else {
        //初始化，将已开辟内存空间 ptr 的首 n(这里n=10)个字节的值设为值 0
        memset(ptr, 0, 10);
        strncpy(ptr, argv[1], 9);
        while (*ptr != 'z'){
           if (*ptr == ' ') break;
           else ptr++;
       }
       if (*ptr == 'z'){
           printf("\n String contains 'z' \n");
           //Do some more processing
       }
        //释放内存空间
       free(ptr);
   }
   return 0;
}