字符串指针 用malloc的例子

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char str_rev(char *s)
{
    
        char *d = s + strlen(s) - 1;
        char temp;
        while(d > s)
        {
                temp = *d;
                *d = *s;
                *s = temp;
                d--;
                s++;
        }
    
}

int main(void)
{
    char *string;
    string = (char *)malloc(20);
    if(NULL == string)
    {
        printf("malloc failure! \n");
        return 1;
    }
    memcpy(string, "hello boy", 9);
    printf("string = %s \n", string);
    str_rev(string);
    printf("string = %s \n", string);
    free(string);
    string = NULL;
    return 0;
}