given fork {
  case $_ < 0 {
    #error
  }
  case $_ > 0 {
    #parent
  }
  default {
    #child
  }
}

##</code><code>##

if ((my $pid = fork()) < 0){
   #error
} elsif ($pid > 0) {
   #parent
} else {
   $child
}

##</code><code>##

if (get_the_boundary_x() < the_user_provided_x()){
   draw_color("green");
elsif (get_the_boundary_x() == the_user_provided_x()){
   draw_color("blue");
else {
   draw_color("red");
}