character stuffing : C program to perform character stuffing on input data stream(networking // link layer activity)

 character stuffing : C program to perform character stuffing on input data stream(networking // link layer activity) 

#include<stdio.h>

#include<stdlib.h>

#define MAXSIZE 100

int main()

{

  char in[MAXSIZE],stuff[MAXSIZE],destuff[MAXSIZE];

  char *p,*q;

  int i;

  

  printf("enter the string to be character stuffed\n");

  scanf("%s",in);

  p=in;

  q=stuff;

  while(*p!='\0')

  {

    if(*p=='d')

    {

      *q=*p;

      p++;

      q++;

      if(*p=='l')

      {

        *q=*p;

        p++;

        q++;

        if(*p=='e')

        {

          *q=*p;

          p++;

          q++;

          *(q++)='d';

          *(q++)='l';

          *(q++)='e';

        }

      }

    }

    else

    {

      *q=*p;

      q++;

      p++;

    }

  }

  

  *q='\0';

  printf("\nthe stuffed string is");

  printf("\n%s",stuff);

  p=stuff;

  q=destuff;

  while(*p!='\0')

  {

    if(*p=='d')

    {

      *q=*p;

      p++;

      q++;

      if(*p=='l')

      {

        *q=*p;

        p++;

        q++;

        if(*p=='e')

        {

          *q=*p;

          p++;

          q++;

  

          for(i=1;i<=3;i++)

          p++;

 

        }

      }

    }

    else

    {

      *q=*p;

      q++;

      p++;

    }

  }

  *q='\0';

  printf("\nthe destuffed string is");

  printf("\n%s\n",destuff);

  return 0;

}