#!/usr/sbin/dtrace -wqs
/*
* guess.d - guessing game in D (DTrace)
*
* $Id: guess.d,v 1.1.1.1 2015/09/30 22:01:09 christos Exp $
*
* USAGE: guess.d
*
* SEE: http://www.brendangregg.com/guessinggame.html
*
* This is written to demonstrate this language versus the same program
* written in other languages.
*
* 11-May-2005 Brendan Gregg Created this.
*/
inline string scorefile = "highscores_d";
dtrace:::BEGIN
{
printf("guess.d - Guess a number between 1 and 100\n\n");
num = 1;
state = 1;
/* Generate random number */
answer = (rand() % 100) + 1;
answer = answer > 0 ? answer : - answer;
}
syscall::write:entry
/state == 1 && pid == $pid/
{
state = 2;
printf("Enter guess %d: ", num);
system("read guess");
pos = 0;
}
syscall::read:entry
/state == 2 && ppid == $pid && arg0 == 3/
{
self->inguess = 1;
self->buf = arg1;
}
syscall::read:return
/self->inguess/
{
key = copyin(self->buf, arg0);
keys[pos] = *(char *)key;
self->buf = 0;
pos++;
}
syscall::read:return
/self->inguess && keys[pos-1] == '\n'/
{
pos -= 2;
fac = 1;
guess = fac * (keys[pos] - '0');
pos--;
fac *= 10;
guess = pos >= 0 ? guess + fac * (keys[pos] - '0') : guess;
pos--;
fac *= 10;
guess = pos >= 0 ? guess + fac * (keys[pos] - '0') : guess;
self->doneguess = 1;
}
syscall::read:return
/self->inguess/
{
self->inguess = 0;
}
/* Play game */
syscall::read:return
/self->doneguess && guess == answer/
{
printf("Correct! That took %d guesses.\n\n", num);
self->doneguess = 0;
state = 3;
printf("Please enter your name: ");
system("/usr/bin/read name");
}
syscall::read:return
/self->doneguess && guess != answer/
{
num++;
printf("%s...\n", guess < answer ? "Higher" : "Lower");
printf("Enter guess %d: ", num);
system("read line");
pos = 0;
}
syscall::read:entry
/state == 3 && curthread->t_procp->p_parent->p_ppid == $pid && arg0 == 0/
{
self->inname = 1;
self->buf = arg1;
}
/* Save high score */
syscall::read:return
/self->inname/
{
self->inname = 0;
name = stringof(copyin(self->buf, arg0 - 1));
system("echo %s %d >> %s", name, num, scorefile);
/* Print high scores */
printf("\nPrevious high scores,\n");
system("cat %s", scorefile);
exit(0);
}