Print all the linux system users that starts with d or D

• With a Perl one liner :D

open(my $fh, ';
map { print $& . "\n" if $_ =~ /^d([^:]*)/  } @user_info;
close $fh;

• Avoiding one-liners

foreach my $user_line (@user_info) {
    if ($user_line =~ /^d([^:]*)/) {
        print $& . "\n";
    }
}