【例11.1】输入一行字符，写入文件data.txt，读取并输出文件data.txt的内容。

#include<stdio.h>
#include<stdlib.h>
int main(void)
{
	FILE *fp;
	char ch;
	fp = fopen("data.txt","w");
	printf("Input a string:");
	scanf("%c",&ch);
	while(ch!='\n')
	{
		fputc(ch,fp);
		scanf("%c",&ch);
	}
	fclose(fp);
	fp=fopen("data.txt","r");
	ch=fgetc(fp);
	while(ch!=EOF)
	{
		printf("%c",ch);
		ch=fgetc(fp);
	}
	printf("\n");
	fclose(fp);
	return 0;
}