my (@opn, @hold);
while (my $line = <DATA>) {
       my ($_date, $id, $code) = split(/ \| /, $line);
       push @opn, $id if ($code =~ /open$/i);
       push @hold, $id if ($code =~ /hold$/i);
}

# do whatever you want with them now..

__DATA__
Date: Jan 1 2001 3:30PM | ID: 1 | Code: open
Date: Jan 1 2001 3:35PM | ID: 1 | Code: open
Date: Jan 1 2001 3:37PM | ID: 1 | Code: hold
Date: Jan 1 2001 3:46PM | ID: 1 | Code: hold
Date: Jan 1 2001 4:10PM | ID: 1 | Code: open
Date: Jan 1 2001 4:35PM | ID: 1 | Code: hold