C语言寻找字符在字符串中的位置

利用char *strchr(const char *str, int c) 函数返回的指针，判断字符c所在的位置

找到第一个位置之后，从该位置的下一个字符起找。

#include 
#include 


int main()
{
    char str[] = "this is a sample string";
    char *pch;
    printf("looking for 's' character in \"%s\"\n ",str); 
    pch = strchr(str,'s');
    printf("str address = %p\n",str);
    printf("pch address = %p\n",pch);
    while(pch != NULL ){
        printf("found at %d\n",pch-str);
        pch = strchr(pch+1,'s');
    }
    return 0;
}