08_Sleep_In_Process.c

// Q. Create a child process using fork() and then use sleep() in parent process

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

int main()
{
	int f;

	printf("Before fork!\n");
	f = fork();

	// The creation of the process was unsuccessful
	if (f < 0)
	{

		printf("Error occurred!\n");
	}

	// Child process
	else if (f == 0)
	{

		printf("This is Child Process!\n");
		printf("Child: Child Process pid: %d\n", getpid());
		printf("Child: Parent Process pid: %d\n", getppid());
	}

	// Parent process
	else
	{

		// Parent process will be in sleep for 5 secs
		// in the meantime execution of the child process will be completed
		sleep(5);
		printf("This is Parent Process!\n");
		printf("Parent: Parent Process pid: %d\n", getpid());
		printf("Parent: Child Process pid: %d\n", f);
	}

	// This part will be executed by both child & parent
	printf("This is common!\n");
}

/*
	Output:

	s4shibam@SHIBAM:~/OS$ gcc 8_Sleep_In_Process.c
	s4shibam@SHIBAM:~/OS$ ./a.out
	Before fork!
	This is Child Process!
	Child: Child Process pid: 2154
	Child: Parent Process pid: 2153
	This is common!
	This is Parent Process!
	Parent: Parent Process pid: 2153
	Parent: Child Process pid: 2154
	This is common!
	s4shibam@SHIBAM:~/OS$
*/