C库函数对文件的操作

int main(int arg, char *args[])
{

//    char s[]="abc.txt";
    FILE* p=fopen(args[1],"r+");
    if(p==NULL)
        printf("error is %s
",strerror(errno));
    else
    {
        printf("success
");
        char buf[100];
        size_t rc=0;
        while(1)
        {
            size_t tmp=fread(buf,1,sizeof(buf),p);//第二个参数*第三个参数不能超过缓冲区
            rc += tmp;
            if(tmp==0)
                break;
        }

        printf("rc=%d
",rc);
        fclose(p);
    }
    return 0;
}