NIELIT2017-SET C-117

Question

How many times the " PROCESS " will be printed  when executing the following program?
main() {
printf(" PROCESS");
fflush();
fork();
fork();
}
a) 8                        b)4                            c)6                                  d)7

Comments

2 fork system calls will produce 3 more child process so total =4 times

Answer 1

Answer 4 :

fflush() will be necessary to hold the output of the process together or print it when it's necessary(Usually when buff is full). Now each fork() will produce 2 child process. So total no of process will be 2²=4. So a total of 4 times "PROCESS" will be printed.

Comments

what if  fflush is removed

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Sir I dont think it will make any difference. Then we will assume that output buffer is already empty. :O

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I was looking for the reason and i found that printf()  is "buffered" it will group the output of a process together and it will print when its necessary(i.e normally when new line is coming or buff is about to flush).