//test.c
#include<stdio.h>

//这个函数用来打印FILE内部的字段
void printFILE(FILE *fp){
    printf("fp->_ptr=%s\n",fp->_ptr);
    printf("fp->_cnt=%d\n",fp->_cnt);
    printf("fp->_base=%s\n",fp->_base);
    printf("fp->_flag=%d\n",fp->_flag);
    printf("fp->_file=%d\n",fp->_file);
    printf("fp->_charbuf=%d\n",fp->_charbuf);
    printf("fp->_bufsiz=%d\n",fp->_bufsiz);
    printf("fp->_tmpfname=%s\n",fp->_tmpfname);
    printf("-------------------------------------");
    printf("-------------------------------------\n");
}

int main(){
    FILE* fp = fopen("./passwd","r"); //打开test.c文件，即本文件
    printFILE(fp);

    char buf[20];
    fread(buf,1,5,fp);      //读取fp中的数据
    printFILE(fp);

    fclose(fp);             //关闭fp
    printFILE(fp);
    return 0;
}