PAR - Perl Archive Toolkit

import options

SEE ALSO
ACKNOWLEDGMENTS
AUTHORS
COPYRIGHT

NAME

PAR - Perl Archive Toolkit

VERSION

This document describes version 0.979 of PAR, released May 13, 2008.

SYNOPSIS

(If you want to make an executable that contains all module, scripts and data files, please consult the pp utility instead. pp used to be part of the PAR distribution but is now shipped as part of the the PAR::Packer manpage distribution instead.)

Following examples assume a foo.par file in Zip format.

To use Hello.pm from ./foo.par:

    % perl -MPAR=./foo.par -MHello
    % perl -MPAR=./foo -MHello          # the .par part is optional

Same thing, but search foo.par in the @INC;

    % perl -MPAR -Ifoo.par -MHello
    % perl -MPAR -Ifoo -MHello          # ditto

Following paths inside the PAR file are searched:

    /lib/
    /arch/
    /i386-freebsd/              # i.e. $Config{archname}
    /5.8.0/                     # i.e. $Config{version}
    /5.8.0/i386-freebsd/        # both of the above
    /

PAR files may also (recursively) contain other PAR files. All files under following paths will be considered as PAR files and searched as well:

    /par/i386-freebsd/          # i.e. $Config{archname}
    /par/5.8.0/                 # i.e. $Config{version}
    /par/5.8.0/i386-freebsd/    # both of the above
    /par/

Run script/test.pl or test.pl from foo.par:

    % perl -MPAR foo.par test.pl        # only when $0 ends in '.par'

However, if the .par archive contains either script/main.pl or main.pl, then it is used instead:

    % perl -MPAR foo.par test.pl        # runs main.pl; @ARGV is 'test.pl'

Use in a program:

    use PAR 'foo.par';
    use Hello; # reads within foo.par

    # PAR::read_file() returns a file inside any loaded PARs
    my $conf = PAR::read_file('data/MyConfig.yaml');

    # PAR::get_filehandle() returns an fh for a file inside any loaded PARs
    my $largeFile = PAR::get_filehandle('data/MyConfig.xml');

    # PAR::par_handle() returns an Archive::Zip handle
    my $zip = PAR::par_handle('foo.par')
    my $src = $zip->memberNamed('lib/Hello.pm')->contents;

You can also use wildcard characters:

    use PAR '/home/foo/*.par';  # loads all PAR files in that directory

Since version 0.950, you can also use a different syntax for loading .par archives:

    use PAR { file => 'foo.par' }, { file => 'otherfile.par' };

Why? Because you can also do this:

    use PAR { file => 'foo.par, fallback => 1 };
    use Foo::Bar;

Foo::Bar will be searched in the system libs first and loaded from foo.par if it wasn't found!

    use PAR { file => 'foo.par', run => 'myscript' };

This will load foo.par as usual and then execute the script/myscript file from the archive. Note that your program will not regain control. When script/myscript exits, so does your main program. To make this more useful, you can defer this to runtime: (otherwise equivalent)

    require PAR;
    PAR->import( { file => 'foo.par', run => 'myscript' } );

If you have the PAR::Repository::Client manpage installed, you can do this:

    use PAR { repository => 'http://foo/bar/' };
    use Module; # not locally installed!

And PAR will fetch any modules you don't have from the specified PAR repository. For details on how this works, have a look at the SEE ALSO section below. Instead of an URL or local path, you can construct an the PAR::Repository::Client manpage object manually and pass that to PAR. If you specify the install => 1 option in the use PAR line above, the distribution containing Module will be permanently installed on your system. (use PAR { repository => 'http://foo/bar', install => 1 };)

Finally, you can combine the run and repository options to run an application directly from a repository! (And you can add the install option, too.)

  use PAR { repository => 'http://foo/bar/', run => 'my_app' };
  # Will not reach this point as we executed my_app,

DESCRIPTION

This module lets you use special zip files, called Perl Archives, as libraries from which Perl modules can be loaded.

It supports loading XS modules by overriding DynaLoader bootstrapping methods; it writes shared object file to a temporary file at the time it is needed.

A .par file is mostly a zip of the blib/ directory after the build process of a CPAN distribution. To generate a .par file yourself, all you have to do is compress the modules under arch/ and lib/, e.g.:

    % perl Makefile.PL
    % make
    % cd blib
    % zip -r mymodule.par arch/ lib/

Afterward, you can just use mymodule.par anywhere in your @INC, use PAR, and it will Just Work. Support for generating .par files is going to be in the next (beyond 0.2805) release of Module::Build.

For convenience, you can set the PERL5OPT environment variable to -MPAR to enable PAR processing globally (the overhead is small if not used); setting it to -MPAR=/path/to/mylib.par will load a specific PAR file. Alternatively, consider using the par.pl utility bundled with the the PAR::Packer manpage distribution, or using the self-contained parl utility which is also distributed with the PAR::Packer manpage on machines without PAR.pm installed.

Note that self-containing scripts and executables created with par.pl and pp may also be used as .par archives:

    % pp -o packed.exe source.pl        # generate packed.exe (see PAR::Packer)
    % perl -MPAR=packed.exe other.pl    # this also works
    % perl -MPAR -Ipacked.exe other.pl  # ditto

Please see SYNOPSIS for most typical use cases.

NOTES

Settings in META.yml packed inside the PAR file may affect PAR's operation. For example, pp provides the -C (--clean) option to control the default behavior of temporary file creation.

Currently, pp-generated PAR files may attach four PAR-specific attributes in META.yml:

    par:
      clean: 0          # default value of PAR_CLEAN
      signature: ''     # key ID of the SIGNATURE file
      verbatim: 0       # was packed prerequisite's PODs preserved?
      version: x.xx     # PAR.pm version that generated this PAR

User-defined environment variables, like PAR_GLOBAL_CLEAN, always overrides the ones set in META.yml. The algorithm for generating caching/temporary directory is as follows:

PAR_GLOBAL_TEMP

PAR_CLEAN

PAR_GLOBAL_TEMP

TEMP/par-USER/temp-PID/

TEMP/par-USER/cache-HASH/

PAR_GLOBAL_TEMP

Here is a description of the variables the previous paths.

TEMP

$ENV{PAR_GLOBAL_TMPDIR}

$ENV{TMPDIR}

$ENV{TEMPDIR}

$ENV{TEMP}

$ENV{TMP}

C:\TEMP

/tmp

USER

$Win32::LoginName

$ENV{USERNAME}

$ENV{USER}

PID

HASH

pp

By default, PAR strips POD sections from bundled modules. In case that causes trouble, you can turn this off by setting the environment variable PAR_VERBATIM to 1.

import options

When you ``use PAR {...}'' or call PAR->import({...}), the following options are available.

  PAR->import({ file => 'foo.par' });
  # or
  PAR->import({ repository => 'http://foo/bar/' });

file: The par filename.; You must pass one option of either 'file' or 'repository'.
repository: A par repository (exclusive of file)
fallback: Search the system @INC before the par.
run: The name of a script to run in the par. Exits when done.
no_shlib_unpack: Skip unpacking bundled dynamic libraries from shlib/$archname. The client may have them installed, or you may wish to cache them yourself. In either case, they must end up in the standard install location (such as /usr/local/lib/) or in $ENV{PAR_TEMP} before you require the module which needs them. If they are not accessible before you require the dependent module, perl will die with a message such as ``cannot open shared object file...''

ACKNOWLEDGMENTS

Nicholas Clark for pointing out the mad source filter hook within the (also mad) coderef @INC hook, as well as (even madder) tricks one can play with PerlIO to avoid source filtering.

Ton Hospel for convincing me to ditch the Filter::Simple implementation.

Uri Guttman for suggesting read_file and par_handle interfaces.

Antti Lankila for making me implement the self-contained executable options via par.pl -O.

See the AUTHORS file in the distribution for a list of people who have sent helpful patches, ideas or comments.

AUTHORS

Audrey Tang <cpan@audreyt.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>. If you need support, however, joining the <par@perl.org> mailing list is preferred.

COPYRIGHT

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

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

PAR - Perl Archive Toolkit