在E盘中创建123.txt.其内容是123456.
#include <stdio.h>
#include <process.h>
int main(){
FILE *fp;
int n;
char ch,filename[50];
printf("please input filename:\n");
scanf("%s",filename);
if((fp=fopen(filename,"r"))==NULL){
printf("can not open this file.\n");
exit(0);
}
ch=fgetc(fp);
while(ch!=EOF){
putchar(ch);
ch=fgetc(fp);
}
n=ftell(fp);
if(6==n)
printf("\n设置密码成功\n");
else
printf("\n设置密码失败\n");
fclose(fp);
return 0;
}
