Fork()

Question

Consider the following pseudo code:

for(i=1;i<=4;i++)
{
fork();
printf("Gate");
}

How many times “Gate” is printed?

Answer 1

30 times.

The answer given in various sources is wrong for this question. I executed the programm in Ubuntu.

For every fork call there will be to print statements here.

first fork call 2process = 2 prints

second fork call 4 process = 4 prints

third fork call 8 process = 8 prints

fourth fork call 16 process = 16 prints

total = 2+4+8+16 = 30 (except the first parent) every process in the derivation of process and child tree will execute print statements.

NOTE:question  is not about how many processes are created. 

Comments

I am getting different outputs on different compilers, like 36, more than 40, or 12 etc.

Answer 2

There will be created 15 new child processes and one parent process, hence Gate should be printed 16 times.