13_4.bak

文件打开关闭

#include<stdio.h>
main(){
FILE *fp;
char ch;
if((fp=fopen(test.c,"w"))==NULL)
{printf("cannot open file\n");
	exit(0);}	
	ch=getchar();
	while(ch!='!')
	{
		if((ch>='a')&&(ch<='z'))ch=ch+('A'-'a')
		fputc(ch,fp);
		putchar(ch);
		ch=getchar();
		}
	fclose(fp);
	}