view release on metacpan or  search on metacpan

lib/Alien/bz2/Installer.pm  view on Meta::CPAN

 
 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
 }

=head1 DESCRIPTION

If you just want to compress or decompress bzip2 data in Perl you
probably want one of L<Compress::Bzip2>, L<Compress::Raw::Bzip2>
or L<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
L<Alien::bz2>.

Where L<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.

=head1 CLASS METHODS

Class methods can be executed without creating an instance of
L<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 L<Alien::bz2::Installer> which can be
queried to retrieve the settings needed to interact with 
bz2 via XS or L<FFI::Raw>.

=head2 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.

=head2 fetch

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

B<NOTE:> using this method may (and probably does) require modules
returned by the L<build_requires|Alien::bz2::Installer#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:

=over 4

=item dir

Directory to download to

=item version

Version to download

=back

=head2 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.