Having problems manipulating two files - i'm a beginner.

Hi
I am trying to open two files in binary read mode and then XOR the contents of these files, character by chharacter, and store the results in a third file (by opening it in Binary write mode). Although i can open the two files but get a whole lot of garbage in the resultant file which is supposed to be having the XORed results. please help me.


Thanks in advance
Manu1

code:-

Code:

#include<stdio.h>
#include<conio.h>
#include<math.h>
#include<stdlib.h>

void main(void)
{
  FILE *fptr, *fptr1, *fptr2, *fptr3, *fptr4;
  char plain[5000], ke[5000], cipher[5000];
  int i = 0, j=0, k=0, pt1[500], kt1[500];
  long int ch, ch1, ch2;
  clrscr();
  printf("\n ENTER PLAIN TEXT (PRESS ENTER TWICE TO EXIT):\n");
  fptr = fopen("ptxt.txt", "w");
  fflush(fptr);
  do {
      fputs(plain, fptr);
      fputs("\n", fptr);
      }
  while(strlen( gets(plain) ) > 0);
  fclose(fptr);
 // fflush(fptr);
  printf("\n ENTER KEY (PRESS ENTER TWICE TO EXIT):\n");
  fptr1 = fopen("ktxt.txt", "w");
  fflush(fptr1);
  do {
       fputs(ke, fptr1);
       fputs("\n", fptr1);
     }
  while(strlen( gets(ke) ) > 0);
  fclose(fptr1);
  //fflush(fptr1);

  fptr4 = fopen("ctxt.txt", "wb");
  fptr2 = fopen("ptxt.txt", "rb");
  fptr3 = fopen("ktxt.txt", "rb");

  fflush(fptr4);

  while (ch = getc(fptr2) != EOF)
  {
    ch1 = getc(fptr3) != EOF;
    cipher[i] = ch ^ ch1;
    i++;
    fwrite(cipher, sizeof(cipher), 1, fptr4);
   // i = j;
  }
/*  while (ch1 = getc(fptr3) != EOF )
  {
    kt1[k] = ch1;
    k++;
  }
    cipher[i] = ch ^ ch1;
   // i++;
   // putc(cipher, fptr4);
    i++;
  }*/
 /* for(k=0; k<j; k++)
  {
    putc(cipher[k], fptr4);
  }*/
  fclose(fptr2);
  fclose(fptr3);
  fclose(fptr4);
 // fflush(fptr4);

}

Can you post your code?

Anoop.

Hi Salem

Thanks a lot for your help.

I can create both files perfectly now, but im still getting the same type of abnormal data when i access the third file (which is supposed to have XORed data from both the files instead. Pl. help me with this. Following is my amended code:

Code:

#include<stdio.h>
#include<conio.h>
#include<math.h>
#include<stdlib.h>

int main(void)
{
  FILE *fptr, *fptr1, *fptr2, *fptr3, *fptr4;
  char plain[5000], ke[5000], cipher[5000];
  int i = 0, j=0, k=0, pt1[500], kt1[500];
  long int ch, ch1, ch2;
  clrscr();
  printf("\n ENTER PLAIN TEXT (PRESS ENTER TWICE TO EXIT):\n");
  fptr = fopen("ptxt.txt", "w");
  
  while(fgets(plain, sizeof(plain),stdin)!= NULL)
  {
      if(plain[0]=='\n')
      break;
      fputs(plain, fptr);
      fputs("\n", fptr);
      }
 
  fclose(fptr);
 
  printf("\n ENTER KEY (PRESS ENTER TWICE TO EXIT):\n");
  fptr1 = fopen("ktxt.txt", "w");
  
  while(fgets(ke, sizeof(ke),stdin)!= NULL)
  {
      if(ke[0]=='\n')
      break;
      fputs(ke, fptr1);
       fputs("\n", fptr1);
  }
 
  fclose(fptr1);
  

  fptr4 = fopen("ctxt.txt", "wb");
  fptr2 = fopen("ptxt.txt", "rb");
  fptr3 = fopen("ktxt.txt", "rb");

  

  while(ch = fgets(plain, sizeof(plain),stdin)!= NULL)
  {
    
    if(ch1 = fgets(ke, sizeof(ke),stdin)!= NULL)
   { cipher[i] = ch ^ ch1;}
    i++;
    fwrite(cipher, sizeof(cipher), 1, fptr4);
  
  }

  fclose(fptr2);
  fclose(fptr3);
  fclose(fptr4);
 
}

I shall be very grateful for this help.
Regards

Manu

I have tried to improve the listing of the program so as to make it more simple to read. Your help will be highly appreciated.
Thanks & regards
Manu

your code is very difficult to read, please edit it and surround in the appropriate tags.

Hey manu1, didn't you like the help that stober gave you at ProgramersHeaven with the question you posted
August 12, 2003 at 3:46:23 AM

It looked like by 8AM you had code working.

Now you post your original code here?

The original post, for those who are interested:
http://www.programmersheaven.com/c/M...ing=A0003F0001

And now you start a new thread?!?!?!!?

Keep using the same thread!
http://cboard.cprogramming.com/showt...threadid=43344

Thanks a lot mates.
Much appreciated.

Manu