Question

(5 pts.) Consider the C program below. Recall that fflush() just forces the printed value to...

  1. (5 pts.) Consider the C program below. Recall that fflush() just forces the printed value to be output immediately. (For space reasons, we are not checking error return codes, so assume that all functions return normally.)

int main () {

   if (fork() == 0) {

       if (fork() == 0) {

          printf("3"); fflush(stdout);

       }

       else {

          pid_t pid; int status;

          if ((pid = wait(&status)) > 0) {

                 printf("4"); fflush(stdout);

          }

       }

   }

   else {

       printf("2"); fflush(stdout);

       exit(0);

   }

   printf("0"); fflush(stdout);

   return 0;

}

For each of the following strings, circle whether (Y = yes) or not (N = no) this string is a possible output:

a. 32040 Y N

            b. 34002 Y N

            c. 30402 Y N

            d. 23040 Y N

            e. 40302 Y N

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Homework Answers

Answer #1

Program :

#include<stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include<sys/wait.h>
int main () {

if (fork() == 0) {

if (fork() == 0) {

printf("3"); fflush(stdout);

}

else {

pid_t pid; int status;

if ((pid = wait(&status)) > 0) {

printf("4"); fflush(stdout);

}

}

}

else {

printf("2"); fflush(stdout);

exit(0);

}

printf("0"); fflush(stdout);

return 0;

}

ANS :

a. 32040 (N)

b. 34002 (N)

c. 30402 (N)

d. 23040 (Y)

e. 40302 (N)

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