SOP k1 05 2

}

for(i = 1; i < 4; i++) if (wait(0) == -1) {

perror("Error in wait"); return 1;

>

return 0;

3. (10 p.) You are given a program:

int main ()

{

pid_t pid; int i;

for (i =    4; 1++)-

switpłf^Cpid = fork()) { case -1:

perror("Error in fork"); return 1; case 0:

execlp("pwd","pwd",0); perror("Error in exec^M); exit(1) ; default:

printf("pid = %d", pid);

>

Mark correct answers (correct answer is worth +2p, while incorrect answer yields

—2p.

(a)    The program creates:

i.    a linę of processes (father, son, grandson etc.),

ii.    a bunch of processes (father and a number of sons),

iii.    a treę of processes,

iv.    one ęhild process.

(b)    The program creates:

i. /l child process,

ii.    3 child processes,

iii.    4 child processes,

iv.    7 child processes.

(c)    Can there appear zombies?

i.    Yes

ii.    No

(d) Which processes output their identi-fiers?

i.    the parent process,

ii.    the child process(es),

iii.    both,

iv.    nonę.

(e) The parent process:

i.    does not wait for the termina-tion of its children,

ii.    waits for the termination of all its children,

iii.    waits for the termination of one child (but not all).