Graham Ollis

NAME

Alien::bz2::Installer - Installer for bz2

VERSION

version 0.05

SYNOPSIS

Build.PL

 # as an optional dep
 use Alien::bz2::Installer;
 use Module::Build;
 
 my %build_args;
 
 my $installer = eval { Alien::bz2::Installer->system_install };
 if($installer)
 {
   $build_args{extra_compiler_flags} = $installer->cflags,
   $build_args{extra_linker_flags}   = $installer->libs,
 }
 
 my $build = Module::Build->new(%build_args);
 $build->create_build_script;

Build.PL

 # require 3.0
 use Alien::bz2::Installer;
 use Module::Build;
 
 my $installer = eval {
   my $system_installer = Alien::bz2::Installer->system_install;
   die "we require 1.0.6 or better"
     if $system->version !~ /^([0-9]+)\.([0-9]+)\.([0-9]+)/ && $1 >= 1 && ($3 >= 6 || $1 > 1);
   $system_installer;
      # reasonably assumes that build_install will never download
      # a version older that 1.0.6
 } || Alien::bz2::Installer->build_install("dir");
 
 my $build = Module::Build->new(
   extra_compiler_flags => $installer->cflags,
   extra_linker_flags   => $installer->libs,
 );
 $build->create_build_script;

FFI::Raw

 # as an optional dep
 use Alien::bz2::Installer;
 use FFI::Raw;
 
 eval {
   my($dll) = Alien::bz2::Installer->system_install->dlls;
   FFI::Raw->new($dll, 'BZ2_bzlibVersion', FFI::Raw::str);
 };
 if($@)
 {
   # handle it if bz2 is not available
 }

DESCRIPTION

If you just want to compress or decompress bzip2 data in Perl you probably want one of Compress::Bzip2, Compress::Raw::Bzip2 or IO::Compress::Bzip2.

This distribution contains the logic for finding existing bz2 installs, and building new ones. If you do not care much about the version of bz2 that you use, and bz2 is not an optional requirement, then you are probably more interested in using Alien::bz2.

Where Alien::bz2::Installer is useful is when you have specific version requirements (say you require 3.0.x but 2.7.x will not do), but would still like to use the system bz2 if it is available.

CLASS METHODS

Class methods can be executed without creating an instance of Alien::bz2::Installer, and generally used to query status of bz2 availability (either via the system or the internet). Methods that discover a system bz2 or build a one from source code on the Internet will generally return an instance of Alien::bz2::Installer which can be queried to retrieve the settings needed to interact with bz2 via XS or FFI::Raw.

versions_available

 my @versions = Alien::bz2::Installer->versions_available;
 my $latest_version = $version[-1];

Returns the list of versions of bzip2 available on the Internet. Will throw an exception if available versions cannot be determined.

fetch

 my($location, $version) = Alien::bz2::Installer->fetch(%options);
 my $location = Alien::bz2::Installer->fetch(%options);

NOTE: using this method may (and probably does) require modules returned by the build_requires method.

Download the bz2 source from the internet. By default it will download the latest version t a temporary directory, which will be removed when Perl exits. Will throw an exception on failure. Options include:

dir

Directory to download to

version

Version to download

build_requires

 my $prereqs = Alien::bz2::Installer->build_requires;
 while(my($module, $version) = each %$prereqs)
 {
   ...
 }

Returns a hash reference of the build requirements. The keys are the module names and the values are the versions.

The requirements may be different depending on your platform.

system_requires

This is like build_requires, except it is used when using the bz2 that comes with the operating system.

system_install

 my $installer = Alien::bz2::Installer->system_install(%options);

NOTE: using this method may require modules returned by the system_requires method.

Options:

test

Specifies the test type that should be used to verify the integrity of the system bz2. Generally this should be set according to the needs of your module. Should be one of:

compile

use test_compile_run to verify. This is the default.

ffi

use test_ffi to verify

both

use both test_compile_run and test_ffi to verify

alien

If true (The default) then an existing Alien::bz2 will be used if found. Usually this is what you want.

build_install

 my $installer = Alien::bz2::Installer->build_install( '/usr/local', %options );

NOTE: using this method may (and probably does) require modules returned by the build_requires method.

Build and install bz2 into the given directory. If there is an error an exception will be thrown. On a successful build, an instance of Alien::bz2::Installer will be returned.

These options may be passed into build_install:

tar

Filename where the bz2 source tar is located. If not specified the latest version will be downloaded from the Internet.

dir

Empty directory to be used to extract the bz2 source and to build from.

test

Specifies the test type that should be used to verify the integrity of the build after it has been installed. Generally this should be set according to the needs of your module. Should be one of:

compile

use test_compile_run to verify. This is the default.

ffi

use test_ffi to verify

both

use both test_compile_run and test_ffi to verify

ATTRIBUTES

Attributes of an Alien::bz2::Installer provide the information needed to use an existing bz2 (which may either be provided by the system, or have just been built using build_install.

cflags

The compiler flags required to use bz2.

libs

The linker flags and libraries required to use bz2.

dlls

List of DLL or .so (or other dynamic library) files that can be used by FFI::Raw or similar.

version

The version of bz2

INSTANCE METHODS

test_compile_run

 if($installer->test_compile_run(%options))
 {
   # You hae a working bz2
 }
 else
 {
   die $installer->error;
 }

Tests the compiler to see if you can build and run a simple bz2 program. On success it will return the bz2 version. Other options include

cbuilder

The ExtUtils::CBuilder instance that you want to use. If not specified, then a new one will be created.

dir

Directory to use for building the executable. If not specified, a temporary directory will be created and removed when Perl terminates.

quiet

Passed into ExtUtils::CBuilder if you do not provide your own instance. The default is true (unlike ExtUtils::CBuilder itself).

test_ffi

 if($installer->test_ffi(%options))
 {
   # You have a working bz2
 }
 else
 {
   die $installer->error;
 }

Test bz2 to see if it can be used with FFI::Raw (or similar). On success, it will return the bz2 version.

error

Returns the error from the previous call to test_compile_run or test_ffi.

SEE ALSO

Alien::bz2
Compress::Bzip2
Compress::Raw::Bzip2
IO::Compress::Bzip2

AUTHOR

Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Graham Ollis.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.