ch27-7.c

C语言程序设计上机指导与练习 冶金工业出版社 刘怀亮

#include "stdio.h"
#include "process.h" 
#include "string.h"

void main() 
{ 
   FILE *fp; 
   char str[100]; 
   int i=0; 
   if((fp=fopen("test","w"))==NULL) 
   { 
      printf("Can't open this file.\n"); 
      exit(0); 
   } 
   printf("Input a string : \n"); 
   gets(str); 
   while(str[i]!='!') 
   { 
      if(str[i]>='a'&&str[i]<='z') 
         str[i]=str[i]-32; 
      fputc(str[i],fp); 
      i++; 
   } 
   fclose(fp); 
   if((fp=fopen("test","r"))==NULL) 
   { 
      printf("can't open test r\n"); 
      exit(0); 
   } 
   fgets(str,strlen(str)+1,fp); 
   printf("Output is : %s",str); 
   fclose(fp); 
}