字符串函数参数传入传出（字符串反转）

/***
strstr.c
***/
#include<stdio.h>
#include<string.h>//求字符串p中abcd出现的次数
//自定义函数接口完成业务函数和main函数分开
int getCount(char *mystr,char *sub,int *ncount)
{int ret = 0;if(mystr == NULL || sub == NULL || ncount == NULL){ret = -1;printf("one of point is NULL\n");return ret;}int tmpCount = 0;char *p = mystr;  //不要轻易改变形参的值do{p = strstr(p,sub);if(p != NULL){tmpCount++;p = p +strlen(sub);}else{break;}}while(*p != '\0');*ncount = tmpCount;   //间接赋值是指针存在的最大意义return ret;
}int main()
{int ret = 0;char *p = "abcd11122abcd3333abcd3456abc";int count = 0;char sub[] = "abcd";ret = getCount(p,sub,&count);if(ret != 0){printf("getCount error ret:%d\n",ret);return ret;}printf("count:%d\n",count);return 0;
}