Using the program listed below, identify the values of pid at lines A, B, C, and D.

#include

#include

#include

int main()

{

pid_t pid, pid1;

/* fork a child process */

pid = fork();

if (pid < 0) { /* error occurred */

fprintf(stderr, "Fork Failed");

return 1;

}

else if (pid == 0) { /* child process */

pid1 = getpid();

printf("child: pid = %d",pid); /* A */

printf("child: pid1 = %d",pid1); /* B */

}

else { /* parent process */

pid1 = getpid() ;

printf("parent: pid = %d",pid); /* C */

printf("parent: pid1 = %d" ,pid1); /* D */

wait(NULL);

}

return 0;

}