字符串子串替换函数

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int replace_str(const char * src, const char * key_src, const char * key, char ** buf);
int replace_count(const char * src, const char * key_src, int * n);
int main()
{
        char * str = "a 123 b 156 LL a f a 1";
        char * buf;
        int ret = 0;
 
        puts("替换前");
        puts(str);
        ret = replace_str(str, "a", "8888", &buf);
        if (ret != 0)
        {
                printf("%d", ret);
                system("pause");
                return -1;
        }
 
        puts("替换后");
        puts(buf);
 
        /*释放内存*/
        if (buf != NULL)
        {
                free(buf);