13_20.cpp

C程序参考,简单易懂,是初学者不可少的参考资料

#include<stdio.h>
#include<process.h>
void main()
{  FILE *fp;char  ch;
   if((fp=fopen("d:\\aaaa.txt","r+"))==NULL)
   {     printf("Cann't Open File d:\\a1.txt");
         exit(0);
   }
   ch=fgetc(fp);
   while(!feof(fp))
   { 
        if(ch!='%')
	{   ch=ch-10;
  fseek(fp,-1L,1);
fputc(ch,fp);
fseek(fp,0L,1);
}
      ch=fgetc(fp);
   }
   fclose(fp);
}