using unix only,

this time only using the signal mechanism system call (don't use wait() or pipe(),

you may still need sleep()). You can still write or read to the disk. You should have one parent process and one child process only.

Your output should look like

x = 19530

ITERATION 1

Parent : x = 19525

Child : x = 3905

ITERATION 2

Parent : x = 3900

Child : x = 780

ITERATION 3

Parent : x = 775

Child : x = 155

ITERATION 4

Parent : x = 150

Child : x = 30

ITERATION 5

Parent : x = 25

Child : x = 5