PAR::FAQ - Frequently Asked Questions about PAR

This is the Frequently Asked Questions list for the Perl Archive Toolkit. You can edit this document at <http://par.perl.org/?FAQ> online.

Do this in the module directory:

    % make clean
    % parl -p

You may also digitally sign the generated .par file:

    % parl -s

PAR::Dist expects to find your MANIFEST in the current directory, and uses Module::Signature to (optionally) sign the newly generated PAR.

The .par file can be uploaded to CPAN along with your module's .tar.gz file. Users of your module can then install from CPAN with a single command:

    % parl -i cpan://PAUSEID/DISTNAME-0.01

Where CWPAUSEID is your PAUSE ID, and CWDISTNAME is your module's distribution name (eg. CWAcme-FooBar).

Comment out the line that starts with CWunless (caller), and compile it again. Note that this is considered a bug; clearing the caller stack is a development in progress. You need to install the libperl-dev package.

Alternatively, create a symbolic link from libperl.so.5.6.1 to libperl.so in /usr/lib:

    % cd /usr/lib; ln -s libperl.so.5.6.1 libperl.so

and re-run the CWmake step of the installation. Unlike Perl2EXE, which can use a standard 16-color bitmap as an application icon, PAR requires a true Windows icon file. Download a trial version of Microangelo (<http://www.microangelo.us/>) and use that to create your .ico file.

The latest Netpbm tools at <http://netpbm.sourceforge.net/> has ppmtowinicon, which can tack a pbm and convert it to a windows icon. It is open source and has win32 ports. As pointed out by Alan Stewart, zip adds a directory entry for the new directory, and it causes the PAR executable to fail.

Just use this :

    zip -r -D hello.par my_dir/

or the Archive::Zip::addTree as follows :

    $zip->addTree( $root, $dest, sub { -f } )

PAR version 0.81 and above supports adding whole directories with CWpp -A, so you do not normally need to add directories this way.

Win32 (with VC++ or MinGW), FreeBSD, NetBSD, Linux, MacOSX, Cygwin, AIX, Solaris, HP-UX, Tru64.

The resulting executable will run on any platforms that supports the binary format of the generating platform.

In other words, "I did a CWpp foo.pl and I lost foo.pl, how do I get it back?".

The answer is to just use unzip/winzip/winrar/whatever to decompress the executable, treating it like a normal Zip file. You may need to rename the executable into a .zip extension first.

Not completely, but possible to a degree. PAR supports an input filter mechanism via CWpp -f and CWpp -F (see PAR::Filter), which can be used to implement source obfuscators (or even product activation schemes).

But if you are looking for 100% bulletproof way of hiding source code, it is not possible with any language. Learning Perl, 3rd Edition has this answer to offer (quoted with permission from Randal Schwartz):

    If you're wishing for an opaque binary, though, we have to tell
    you that they don't exist. If someone can install and run your
    program, they can turn it back into source code. Granted, this
    won't necessarily be the same source that you started with, but
    it will be some kind of source code. The real way to keep your
    secret algorithm a secret is, alas, to apply the proper number
    of attorneys; they can write a license that says "you can do
    this with the code, but you can't do that. And if you break our
    rules, we've got the proper number of attorneys to ensure that
    you'll regret it."

On Microsoft Windows, start your script with

    use strict;
    use Encode::Unicode;
    use Tk;

Some widgets use xbm bitmaps which don't get picked up by PAR. The error is:

    couldn't read bitmap file "": No such file or directory at Tk/Widget.pm line 203
    error reading bitmap file "" at Tk/Widget.pm line 205.

Fix is to find the missing xbm files (CWperl -V tells you where to start looking), copy them to the script directory, and add them to the executable:

    pp -a cbxarrow.xbm -a arrowdownwin.xbm -o test test.pl

Note that this problem should only happen if the perl version of both programs are binary-incompatible.

When running on a Win32 system, if a perl script is packed with pp and invokes another Perl script or pp packed executable, either with CWsystem() or backticks, the invoked program runs with the copy of perl5x.dll already loaded into memory.

If the calling executable was packed with CWpp -d, the perl5x.dll is the one from the installed perl bin directory. Otherwise, it is the one packed with the executable.

The perl5x.dll from the bin dir knows the CW@INC paths for the installed libraries; the one in the executable does not. Because of this, a program packed without CW-d calling a program with packed with CW-d or calling perl.exe to run a plain Perl script may fail. This is a Win32 limitation.

Use the CWpp --gui option, like this:

    % pp --gui -o file.exe file.pl

Use the CWpp --icon option, like this:

    % pp --icon "c:\path\to\MyIcon.ico" -o file.exe file.pl

You may be able to escape this problem by setting some executables to Windows 95 compatibility mode. Specifically, find parl.exe (probably in C:\perl\5.8.0\bin) using Windows Explorer, and right-click on it and choose CWProperties. Choose the Compatibility tab and tick the box for CWRun this program with compatibility mode for and check that the dropdown shows CWWindows 95. Then click OK.

Now you can hopefully run pp as normal to generate an EXE. Before you can run the generated EXE, you'll need to set its compatibility mode too, in the same way as you did for parl.exe.

This bug has been be fixed. The following answer applies to PAR 0.79 and earlier:

With a script my.pl using Win32::Perms, running CWpp -o my.exe my.pl may produce this:

    Can't locate loadable object for module Win32::Perms in @INC (@INC 
    contains: CODE(0) CODE(0) .) at ../blib/lib/PAR/Heavy.pm 
    line 78

In fact the dll is Perms.DLL wit DLL in capital letters. That's the problem. The bootstrap function of PAR in the Dynaloader module fails looking for Perms.dll in the table of dlls which contains only Perms.DLL.

And so the solution is just rename Perms.DLL to Perms.dll and do CWpp -o my.exe my.pl again... and everything goes right!

PAR, PAR::Tutorial

Autrijus Tang <autrijus@autrijus.org>

<http://par.perl.org/> is the official PAR website. You can write to the mailing list at <par@perl.org>, or send an empty mail to <par-subscribe@perl.org> to participate in the discussion.

Please submit bug reports to <bug-par@rt.cpan.org>.

Copyright 2003, 2004, 2005 by Autrijus Tang <autrijus@autrijus.org>.

This document is free documentation; you can redistribute it and/or modify it under the same terms as Perl itself.

See <http://www.perl.com/perl/misc/Artistic.html>