Question

I have the following code and am asked to how many times “A”, “B”, “C”, “D”, “E” will be printed

fun() {
  printf("A");
  fork();
  printf("B");
  if (fork() != 0) {
     printf("C");
     fork();
     printf("D");
  }
  printf("E");
}

so it should be:

A
A 
B
E

im not sure if my answer above is correct? and what the line if(fork() !=0 ) do?

Answer 1

1 thread prints a, 2 threads print b. each of the 2 forks, but only the 2 parents go into the if statement and print c. Each of those two fork and all 4 procs print d. Then, each of the 6 procs (two children from if-fork and 4 threads coming out of if print e.

You can’t determine the order, but the number of each letter is:

A x1

b x2

c x2

d x4

e x6