#include<stdio.h>
#include<stdlib.h>
#include<ctype.h>
int fun()
{
int ch;
int ret=0;
while(isdigit(ch=getchar()))
{
ret=ret*10+ch-48;
}
ungetc(ch,stdin);
return ret;
}
void fun1()
{
int ch;
int ret=fun();
printf("%d\n",ret);
ch=getchar();
putchar(ch);
}
void fun2()
{
FILE *fp=fopen("1.txt","r");
char ch=fgetc(fp); printf("%c\n",ch);
ch=fgetc(fp); printf("%c\n",ch);
fseek(fp,-2,SEEK_CUR);//当前
ch=fgetc(fp);
printf("%c\n",ch);
fseek(fp,-5,SEEK_END);//末尾
//rename("1.txt","22.txt"); //改文件名为22.txt 需要带后缀的全名
fclose(fp);
//rename("1.txt","22.txt"); 关闭文件或者不关闭文件均可以实现改名字
printf("%c\n",ch);
}
void main()
{
fun1();
#if(1)
fun2();
#endif
}原文:http://sts609.blog.51cto.com/11227442/1749370