#include <unistd.h>
#include <stdio.h>


int main(int argc,char* argv[]){
	if(argc == 2){pid_t forkRE;forkRE = fork();
		if(forkRE==0){
	printf("Child's Process ID : %d \n",getpid());
	printf("Child's parent ID : %d \n",getppid());
	printf("Child's process group ID : %d \n\n",getpgrp());
	//execv("/bin/cat",argv);
	execl("/bin/cat","/bin/cat",argv[1],NULL);
		}else{
		wait(NULL);
	printf("Parent's Process ID : %d \n",getpid());
	printf("Parent's Parent ID : %d \n",getppid());
	printf("Parent's Process Group ID : %d \n\n",getpgrp());
		}
	}
	else
	printf("Error!!! \nTry again :) \n");
	return 0;
}