Doubt about fork()

Question

#include <stdio.h>

int main(void) {
    int i=0;
    printf("HAI\n");
    for(i=1;i<=3;i++)
    {
        if(fork()==0)
            printf("*");
    }
    
    return 0;
}

 

How many times * will be printed? and How many times HAI will be printed?

Comments

According to me 6 *'s will be printed and only 1 HAI will be printed.... and moreover there are 3 parent processes and 4 child processes at the end

but none of the online compilers shouldn't print these values.... Correct me if i am wrong... and mention which compiler is to use for gate purpose...

---

@tusharp

i just pinged you !

Answer 1

The number of "HAI" printed will be 1 time which will be at the beginning

The number of "*" printed will be 2ⁿ-1 = 2³-1 = 7

The structure will be

where the diamond represents if condition

More information on fork can be found here- http://www.csl.mtu.edu/cs4411.ck/www/NOTES/process/fork/create.html

Answer 2

Total number of fork() call in parent process =3 (according to loop).

Total number of child processes = 2³-1 ; Thus  "*" will be printed 7 times.   HAI will be printed 1 time.