/*IMPLEMENTATION OF BIT STUFFING AND CHARACTER STUFFING*/

#include<stdio.h>

#include<conio.h>

#include<stdlib.h>

main()

{

   int ch;

   clrscr();

   do

   {

      printf("\n********************:");

      printf("\n1.BIT STUFFING:");

      printf("\n2.CHARACTER STUFFING:");

      printf("\n3.EXIT:");

      printf("\n*********************");

      printf("\nEnter your choice:");

      scanf("%d",&ch);

      switch(ch)

      {

            case 1:bit();

                   break;

            case 2:character();

                   break;

            case 3:exit(0);

      }

   }while(ch!=3);

   getch();

}

bit()

{

   FILE *fp,*fp1;

   char ch;

   int i;

   if((fp=fopen("source.txt","w"))==NULL)

   {

      printf("\nError in opening the file");

      exit(0);

   }

   printf("\nEnter data to send press 'e' to end :\n");

   i=0;

   while(1)

   {

       scanf("%c",&ch);

       if(ch=='e')

               break;

       if(ch=='1')

               i++;

       else

               i=0;

       putc(ch,fp);

       if(i==5)

       {

              putc('0',fp);

              i=0;

       }

   }

   fclose(fp);

   i=0;

   fp=fopen("source.txt","r");

   fp1=fopen("dest.txt","w");

   printf("\nDATA AFTER STUFFING\n");

   while((ch=getc(fp))!=EOF)

   {

      putc(ch,stdout);

   }

   fseek(fp,0L,0);

   printf("\nDATA AFTER UNSTUFFING\n");

   while((ch=getc(fp))!=EOF)

   {

      if(ch=='1')

              i++;

      else

             i=0;

      if(i==5)

      {

             putc(ch,stdout);

             putc(ch,fp1);

             ch=getc(fp);

             i=0;

      }

      else

      {

             putc(ch,stdout);

             putc(ch,fp1);

      }

   }

   fclose(fp);

   fclose(fp1);

}

character()

{

   FILE *fp,*fp1;

   char ch,c[2],k[4],j[9];

   long beg,end;

   if((fp=fopen("Input.txt","w"))==NULL)

   {

      printf("\n Input.txt file opening problem...");

      exit(0);

   }

   printf("\nEnter data to send at end put '}': \n\n");

   while(1)

   {

      scanf("%c",&ch);

      if(ch=='}')

             break;

      putc(ch,fp);

   }

   fclose(fp);

   if((fp=fopen("Input.txt","r"))==NULL)

   {

      printf("\nInput.txt file opening problem...");

      exit(0);

   }

   if((fp1=fopen("csource.txt","w"))==NULL)

   {

      printf("\ncsource.txt file opening problem...");

      exit(0);

   }

   fputs(" DLE STX ",fp1);

   while((ch=getc(fp))!=EOF)

   {

 

      if(ch=='D')

      {

 

             c[0]=getc(fp);

             c[1]=getc(fp);

             if(c[0]=='L'&&c[1]=='E')

                fputs("DLE",fp1);

             putc(ch,fp1);

             putc(c[0],fp1);

             putc(c[1],fp1);

      }

      else

             putc(ch,fp1);

   }

   fputs(" DLE ETX ",fp1);

   fclose(fp);

   fclose(fp1);

   if((fp=fopen("csource.txt","r"))==NULL)

   {

            printf("\ncsource.txt file opening problem...");

            exit(0);

   }

   if((fp1=fopen("cdest.txt","w"))==NULL)

   {

            printf("\ncdest.txt file opening problem...");

            exit(0);

   }

   beg=ftell(fp);

   beg+=9;

   fseek(fp,-0L,2);

   end=ftell(fp);

   end-=9;

   fclose(fp);

   printf("\nData after stuffing ");

   fp=fopen("csource.txt","r");

   while((ch=getc(fp))!=EOF)

            putc(ch,stdout);

   fclose(fp);

   printf("\n");

   printf("\nThe data after destuffing");

   fp=fopen("csource.txt","r");

   fgets(j,9,fp);

   while(beg<=end)

   {

            ch=getc(fp);

            if(ch=='D')

            {

              c[0]=getc(fp);

              c[1]=getc(fp);

              if(c[0]=='L'&&c[1]=='E')

              {

                 fgets(k,4,fp);

                 beg+=4;

              }

              else

              {

                 putc(ch,fp1);

                 putc(c[0],fp1);

                 putc(c[1],fp1);

                 putc(ch,stdout);

                 putc(c[0],stdout);

                 putc(c[1],stdout);

              }

            }

            else

            {

              putc(ch,fp1);

              putc(ch,stdout);

            }

            beg++;

   }

   fclose(fp);

   fclose(fp1);

}

 

 

OUTPUT

 

 

********************:

1.BIT STUFFING:

2.CHARACTER STUFFING:

3.EXIT:

*********************

Enter your choice:1

 

Enter data to send press 'e' to end :

11100000111111111101e

 

DATA AFTER STUFFING

 

1110000011111011111001

DATA AFTER UNSTUFFING

 

11100000111111111101

********************:

1.BIT STUFFING:

2.CHARACTER STUFFING:

3.EXIT:

*********************

Enter your choice:2

 

Enter data to send at end put '}':

 

This is DLE idle DLE program}

 

Data after stuffing

 DLE STX This is DLEDLE idle DLEDLE program DLE ETX

 

The data after destuffing

This is  idle  program

********************:

1.BIT STUFFING:

2.CHARACTER STUFFING:

3.EXIT:

*********************

Enter your choice:3