Assuming that the system call fork () never fails, consider the following C programs P1 and P2 executed on a UNIX / Linux system:

/*P1*/ Int main() { fork (): fork () ; fork () ; Printf(“Happy\n”); }

/*P2*/ Int main() { fork (); Printf(“Happy\n”); fork () Printf(“Happy\n”); fork () ; Printf(“Happy\n”); }

 

Statement I: P1 displays "Happy" 8 times.

Statement II: P2 displays "Happy" 12 times.

In the light of the above statements, choose the correct answer from the options given below

The correct answer is option 3

Explanation:

fork() is a system call used to create a child process.

Once a child process is created, both the parent process and the child process run the next line following the fork() command simultaneously.

'n' number of successive for() calls create 2ⁿ - 1 child processes.

in P1:

Each child process prints one "Happy".

Parent process also prints one "Happy".

So, number of times P1 displays "Happy" = (2³ - 1) + 1 = 8

In P2:

At first fork(), a new child process with two fork() and printf statements is created.

Similarly, more child processes are created at each fork() command.

So, P2 shows "Happy" 14 (2 + 4 + 8 )times.