Question

Write a C program that spins a child process. The child process reads a number from the keyboard and passes the number on to the parent process via a pipe. The parent process waits until number becomes available and reads it from the pipe, prints the number to the screen and exits.

Answer 1

# include <stdio.h>

int main()

{    

   int pid;

   pid=getpid();

   printf(\"Current Process ID is : %d\\n\",pid);

   printf(\"[ Forking Child Process ... ] \\n\");    

   pid=fork(); /* This will Create Child Process and

              Returns Child\'s PID */

   if(pid < 0)

   {

       /* Process Creation Failed ... */

       exit(-1);

   }

   else if(pid==0)  

   {

       /* Child Process */

       printf(\"Child Process Started ...\\n\");

       printf(\"Child Process Completed ...\\n\");

   }

   else  

   {

       /* Parent Process */

       sleep(10);

       printf(\"Parent Process Running ... \\n\");

       printf(\"I am In Zombie State ...\\n\");

       while(1)

       {

           /*  

               Infinite Loop that Keeps the

                  Process Running

           */

       }

   }    

   return 0;

}

# include <stdio.h>

int main()

{    

   int pid;

   pid=getpid();

   printf(\"Current Process ID is : %d\\n\",pid);

   printf(\"[ Forking Child Process ... ] \\n\");    

   pid=fork(); /* This will Create Child Process and

              Returns Child\'s PID */

   if(pid < 0)

   {

       /* Process Creation Failed ... */

       exit(-1);

   }

   else if(pid==0)  

   {

       /* Child Process */

       printf(\"Child Process Started ...\\n\");

       printf(\"Child Process Completed ...\\n\");

   }

   else  

   {

       /* Parent Process */

       sleep(10);

       printf(\"Parent Process Running ... \\n\");

       printf(\"I am In Zombie State ...\\n\");

       while(1)

       {

           /*  

               Infinite Loop that Keeps the

                  Process Running

           */

       }

   }    

   return 0;

}