title: Interchange contents of two files
body: <p>I have the below code, I am trying to interchange contents of two files.
  I am able to interchange two files by using the below code.
  Is there any way to interchange two files other than the following method.</p>
  
  <pre><code># include &lt;stdio.h&gt;
  # include &lt;conio.h&gt;
  # include &lt;process.h&gt;
  
  void main()
  {
      FILE *f1,*f2,*f3;
      char ch;
      f1=fopen("E:/FileText.txt","r");
      f2=fopen("E:/CombineContents.txt","r");
      f3=fopen("E:/FileCopy.txt","w");
      if(f1==NULL)
      {
          printf("Cannot open file");
          getche();
          exit(1);
      }
      if(f2==NULL)
      {
          printf("Cannot open file");
          getche();
          exit(1);
      }
      if(f3==NULL)
      {
          printf("Cannot open file");
          getche();
          exit(1);
      }
  
  
      printf("\nCopying contents from f2 to f3:");
      while(!feof(f2))
      {
          fputc(fgetc(f2),f3);
      }
      fcloseall();
      printf("\nContents copied from f2 to f3 are :");
      f3=fopen("E:/FileCopy.txt","r");
      while((ch=fgetc(f3))!=EOF)
      {
          printf("%c",ch);
      }
      fclose(f3); 
      getche();
  
  
      printf("\nCopying contents from f1 to f2:");
      f1=fopen("E:/FileText.txt","r");
      f2=fopen("E:/CombineContents.txt","w");
      if(f1==NULL || f2==NULL)
      {
          printf("Cannot open file");
          getche();
          exit(1);
      }
      while(!feof(f1))
      {
          fputc(fgetc(f1),f2);
      }
      fcloseall();
      printf("\n Contents copied from f1 to f2 are :");
      f2=fopen("E:/CombineContents.txt","r");
      while((ch=fgetc(f2))!=EOF)
      {
          printf("%c",ch);
      }
      fclose(f2);
      getche();
  
  
      printf("\nCopying contents from f3 to f1:");
      f3=fopen("E:/FileCopy.txt","r");
      f1=fopen("E:/FileText.txt","w");
      if(f1==NULL || f3==NULL)
      {
          printf("Cannot open file");
          getche();
          exit(1);
      }
      while(!feof(f3))
      {
          fputc(fgetc(f3),f1);
      }
      fcloseall();
      printf("\nContents copied are:");
      f1=fopen("E:/FileText.txt","r");
      while((ch=fgetc(f1))!=EOF)
      {
          printf("%c",ch);
      }
      fclose(f1);
      getche();
  
  }
  </code></pre>