从键盘输入字符后，写入到磁盘文件datafile1.txt中

#include<stdio.h>
void main()
{
FILE * fp1;
char str1;
if((fp1=fopen("C:\\datafile1.txt","w"))==NULL)
{
   printf("file cannot be opened\n");
   exit(1);
   }
   while((str1=fgetc(stdin))!='\n')
   fputc(str1,fp1);
   fclose(fp1);
}

读出磁盘文件datafile.txt中的内容，将它们显示在屏幕上

#include<stdio.h>
void main()
{
FILE * fp;
char str1;
if((fp=fopen("C:\\datafile.txt","r"))==NULL)
{
   printf("file cannot be opened\n");
   exit(1);
   }
   while((str1=fgetc(fp))!=EOF)
   fputc(str1,stdout);
   fclose(fp);
}