1 #include "string.h"
2 int main() 
3 {
4    char *src = "hello,world";
5    char *dest = NULL;
6    int len = strlen(src);
7    dest = (char *)malloc(len);
8    char *d = dest;
9    char *s = src[len];
10   while (len-- != 0)
11      *d++ = *s--;
12   printf("%s", dest);
13   return 0;
14     
15}