GUI scripts
    version 2.1

    The standard perl.exe is a console based application, this is the right
    thing usually, but sometimes it might be tedious.

    Imagine you have a Tk or Win32::GUI based script, you start it by a
    doubleclick on an icon and an ugly empty useless console appears and
    stays on screen until you close the script. Not a nice thing huh?

    There are several solutions.

  Hiding the console
    You may hide the console as soon as the script starts.

    use Win32::GUI; BEGIN
    {Win32::GUI::Hide(scalar(Win32::GUI::GetPerlWindow()))};

    There are three problems with this solution.

    The first is that the console flashes on screen when you start the
    program. Even if you use BEGIN{} to hide it as soon as possible.

    Second, if you run such a script from a console, it will hide the
    console instead of detaching itself and leaving the console visible and
    ready to take other commands.

    Now let's think about what to do when the script ends. If it keeps the
    console hidden and it was started by a doubleclick on an icon everything
    is cool, but if it was started from a command prompt, the prompt is
    still running, but it's invisible. This way, you'd run out of memory.

    If you on the other hand show the console, it may flash on screen.

  Solutions
    For some time I advertised a way to prepare a perl.exe that doesn't
    create a console. This is no longer needed if you use ActivePerl. The
    distribution contains wperl.exe which is just that. If you compiled Perl
    yourself you may need to create such an executable yourself. It's easier
    than it may seem:

    All you have to do is to copy your perl.exe to wperl.exe and run this :

    c:\> EDITBIN.EXE /subsystem:windows wperl.exe

    I'm using extension .gpl for the scripts that are to be run by wperl,
    but this is up to you.

    Since the editbin.exe is part of Microsoft's development tools and AFAWK
    is not free, Jan wrote the following script that is able to do the same.

     Usage:
      exetype c:\perl\bin\guiperl.exe WINDOWS

    I've tested this both under WinNT4.0 (sp4) and Win95sp1.

    An updated version of the script is now installed with ActivePerl as
    c:\perl\bin\exetype.bat.

    You may use it to "de-consolize" any EXEcutable of course ;-)

  Script
    This script was written by Jan Dubois <jand@ActiveState.com>. Thanks,
    Jan :-)

     ============================exetype.pl=============================
     #!perl
     use strict;
     unless (@ARGV == 2) {
         print "Usage: $0 exefile [CONSOLE|WINDOWS]\n";
         exit;
     }
     unless ($ARGV[1] =~ /^(console|windows)$/i) {
         print "Invalid subsystem $ARGV[1], please use CONSOLE or WINDOWS\n";
         exit;
     }
     my ($record,$magic,$offset,$size);
     open EXE, "+< $ARGV[0]" or die "Cannot open $ARGV[0]: $!";
     binmode EXE;
     read EXE, $record, 32*4;
     ($magic,$offset) = unpack "Sx58L", $record;
     die "Not an MSDOS executable file" unless $magic == 0x5a4d;
     seek EXE, $offset, 0;
     read EXE, $record, 24;
     ($magic,$size) = unpack "Lx16S", $record;
     die "PE header not found" unless $magic == 0x4550;
     die "Optional header not in NT32 format" unless $size == 224;
     seek EXE, $offset+24+68, 0;
     print EXE pack "S", uc($ARGV[1]) eq 'CONSOLE' ? 3 : 2;
     close EXE;

  Automatic setup
    I've written a script that creates the wperl.exe (if you do not have it
    already) and sets the file extension mapping for extensions you specify.
    You may find it at http://Jenda.Krynicky.cz/perl/makeGUIperl.pl.txt

    You need Win32::Registry2 patch from my pages! http://Jenda.Krynicky.cz

  Subprocesses
    If your application doesn't have a console, your subprocesses should not
    have one either. It would look dirty if a console flicked on the screen
    every time you use system() or backticks. Since build 632 of ActivePerl
    you may use this

            BEGIN {
                    Win32::SetChildShowWindow(0)
                            if defined &Win32::SetChildShowWindow
            };

    to instruct Perl to hide the consoles of such processes.

  Author
    The text was written by Jan Krynicky <Jenda@Krynicky.cz> and is based on
    discussion on Perl-Win32-Users mailing list, the code is by Jan Dubois
    <jand@ActiveState.com>.