1 # -*- mode: cperl; tab-width: 8; indent-tabs-mode: nil; basic-offset: 2 -*-
2 # vim:ts=8:sw=2:et:sta:sts=2
3 package Module::Metadata;
5 # Adapted from Perl-licensed code originally distributed with
6 # Module-Build by Ken Williams
8 # This module provides routines to gather information about
9 # perl modules (assuming this may be expanded in the distant
10 # parrot future to look at other types of modules).
15 our $VERSION = '1.000014';
16 $VERSION = eval $VERSION;
21 # Try really hard to not depend ony any DynaLoaded module, such as IO::File or Fcntl
23 require Fcntl; Fcntl->import('SEEK_SET'); 1;
24 } or *SEEK_SET = sub { 0 }
28 if ($INC{'Log/Contextual.pm'}) {
29 Log::Contextual->import('log_info');
31 *log_info = sub (&) { warn $_[0]->() };
34 use File::Find qw(find);
36 my $V_NUM_REGEXP = qr{v?[0-9._]+}; # crudely, a v-string or decimal
38 my $PKG_FIRST_WORD_REGEXP = qr{ # the FIRST word in a package name
39 [a-zA-Z_] # the first word CANNOT start with a digit
41 [\w']? # can contain letters, digits, _, or ticks
42 \w # But, NO multi-ticks or trailing ticks
46 my $PKG_ADDL_WORD_REGEXP = qr{ # the 2nd+ word in a package name
47 \w # the 2nd+ word CAN start with digits
49 [\w']? # and can contain letters or ticks
50 \w # But, NO multi-ticks or trailing ticks
54 my $PKG_NAME_REGEXP = qr{ # match a package name
55 (?: :: )? # a pkg name can start with aristotle
56 $PKG_FIRST_WORD_REGEXP # a package word
58 (?: :: )+ ### aristotle (allow one or many times)
59 $PKG_ADDL_WORD_REGEXP ### a package word
60 )* # ^ zero, one or many times
62 :: # allow trailing aristotle
66 my $PKG_REGEXP = qr{ # match a package declaration
67 ^[\s\{;]* # intro chars on a line
68 package # the word 'package'
70 ($PKG_NAME_REGEXP) # a package name
71 \s* # optional whitespace
72 ($V_NUM_REGEXP)? # optional version number
73 \s* # optional whitesapce
74 [;\{] # semicolon line terminator or block start (since 5.16)
77 my $VARNAME_REGEXP = qr{ # match fully-qualified VERSION name
78 ([\$*]) # sigil - $ or *
80 ( # optional leading package name
81 (?:::|\')? # possibly starting like just :: (Ì la $::VERSION)
82 (?:\w+(?:::|\'))* # Foo::Bar:: ...
88 my $VERS_REGEXP = qr{ # match a VERSION definition
90 \(\s*$VARNAME_REGEXP\s*\) # with parens
92 $VARNAME_REGEXP # without parens
95 =[^=~] # = but not ==, nor =~
100 my $filename = File::Spec->rel2abs( shift );
102 return undef unless defined( $filename ) && -f $filename;
103 return $class->_init(undef, $filename, @_);
106 sub new_from_handle {
109 my $filename = shift;
110 return undef unless defined($handle) && defined($filename);
111 $filename = File::Spec->rel2abs( $filename );
113 return $class->_init(undef, $filename, @_, handle => $handle);
118 sub new_from_module {
123 $props{inc} ||= \@INC;
124 my $filename = $class->find_module_by_name( $module, $props{inc} );
125 return undef unless defined( $filename ) && -f $filename;
126 return $class->_init($module, $filename, %props);
131 my $compare_versions = sub {
132 my ($v1, $op, $v2) = @_;
133 $v1 = version->new($v1)
134 unless UNIVERSAL::isa($v1,'version');
136 my $eval_str = "\$v1 $op \$v2";
137 my $result = eval $eval_str;
138 log_info { "error comparing versions: '$eval_str' $@" } if $@;
143 my $normalize_version = sub {
145 if ( $version =~ /[=<>!,]/ ) { # logic, not just version
146 # take as is without modification
148 elsif ( ref $version eq 'version' ) { # version objects
149 $version = $version->is_qv ? $version->normal : $version->stringify;
151 elsif ( $version =~ /^[^v][^.]*\.[^.]+\./ ) { # no leading v, multiple dots
152 # normalize string tuples without "v": "1.2.3" -> "v1.2.3"
153 $version = "v$version";
161 # separate out some of the conflict resolution logic
163 my $resolve_module_versions = sub {
164 my $packages = shift;
166 my( $file, $version );
168 foreach my $p ( @$packages ) {
169 if ( defined( $p->{version} ) ) {
170 if ( defined( $version ) ) {
171 if ( $compare_versions->( $version, '!=', $p->{version} ) ) {
172 $err .= " $p->{file} ($p->{version})\n";
174 # same version declared multiple times, ignore
178 $version = $p->{version};
181 $file ||= $p->{file} if defined( $p->{file} );
185 $err = " $file ($version)\n" . $err;
200 croak "provides() requires key/value pairs \n" if @_ % 2;
203 croak "provides() takes only one of 'dir' or 'files'\n"
204 if $args{dir} && $args{files};
206 croak "provides() requires a 'version' argument"
207 unless defined $args{version};
209 croak "provides() does not support version '$args{version}' metadata"
210 unless grep { $args{version} eq $_ } qw/1.4 2/;
212 $args{prefix} = 'lib' unless defined $args{prefix};
216 $p = $class->package_versions_from_directory($args{dir});
219 croak "provides() requires 'files' to be an array reference\n"
220 unless ref $args{files} eq 'ARRAY';
221 $p = $class->package_versions_from_directory($args{files});
224 # Now, fix up files with prefix
225 if ( length $args{prefix} ) { # check in case disabled with q{}
226 $args{prefix} =~ s{/$}{};
227 for my $v ( values %$p ) {
228 $v->{file} = "$args{prefix}/$v->{file}";
235 sub package_versions_from_directory {
236 my ( $class, $dir, $files ) = @_;
245 push @files, $_ if -f $_ && /\.pm$/;
251 # First, we enumerate all packages & versions,
252 # separating into primary & alternative candidates
254 foreach my $file (@files) {
255 my $mapped_filename = File::Spec::Unix->abs2rel( $file, $dir );
256 my @path = split( /\//, $mapped_filename );
257 (my $prime_package = join( '::', @path )) =~ s/\.pm$//;
259 my $pm_info = $class->new_from_file( $file );
261 foreach my $package ( $pm_info->packages_inside ) {
262 next if $package eq 'main'; # main can appear numerous times, ignore
263 next if $package eq 'DB'; # special debugging package, ignore
264 next if grep /^_/, split( /::/, $package ); # private package, ignore
266 my $version = $pm_info->version( $package );
268 $prime_package = $package if lc($prime_package) eq lc($package);
269 if ( $package eq $prime_package ) {
270 if ( exists( $prime{$package} ) ) {
271 croak "Unexpected conflict in '$package'; multiple versions found.\n";
273 $mapped_filename = "$package.pm" if lc("$package.pm") eq lc($mapped_filename);
274 $prime{$package}{file} = $mapped_filename;
275 $prime{$package}{version} = $version if defined( $version );
278 push( @{$alt{$package}}, {
279 file => $mapped_filename,
286 # Then we iterate over all the packages found above, identifying conflicts
287 # and selecting the "best" candidate for recording the file & version
289 foreach my $package ( keys( %alt ) ) {
290 my $result = $resolve_module_versions->( $alt{$package} );
292 if ( exists( $prime{$package} ) ) { # primary package selected
294 if ( $result->{err} ) {
295 # Use the selected primary package, but there are conflicting
296 # errors among multiple alternative packages that need to be
299 "Found conflicting versions for package '$package'\n" .
300 " $prime{$package}{file} ($prime{$package}{version})\n" .
304 } elsif ( defined( $result->{version} ) ) {
305 # There is a primary package selected, and exactly one
306 # alternative package
308 if ( exists( $prime{$package}{version} ) &&
309 defined( $prime{$package}{version} ) ) {
310 # Unless the version of the primary package agrees with the
311 # version of the alternative package, report a conflict
312 if ( $compare_versions->(
313 $prime{$package}{version}, '!=', $result->{version}
318 "Found conflicting versions for package '$package'\n" .
319 " $prime{$package}{file} ($prime{$package}{version})\n" .
320 " $result->{file} ($result->{version})\n"
325 # The prime package selected has no version so, we choose to
326 # use any alternative package that does have a version
327 $prime{$package}{file} = $result->{file};
328 $prime{$package}{version} = $result->{version};
332 # no alt package found with a version, but we have a prime
333 # package so we use it whether it has a version or not
336 } else { # No primary package was selected, use the best alternative
338 if ( $result->{err} ) {
340 "Found conflicting versions for package '$package'\n" .
345 # Despite possible conflicting versions, we choose to record
346 # something rather than nothing
347 $prime{$package}{file} = $result->{file};
348 $prime{$package}{version} = $result->{version}
349 if defined( $result->{version} );
353 # Normalize versions. Can't use exists() here because of bug in YAML::Node.
354 # XXX "bug in YAML::Node" comment seems irrelevant -- dagolden, 2009-05-18
355 for (grep defined $_->{version}, values %prime) {
356 $_->{version} = $normalize_version->( $_->{version} );
367 my $filename = shift;
370 my $handle = delete $props{handle};
371 my( %valid_props, @valid_props );
372 @valid_props = qw( collect_pod inc );
373 @valid_props{@valid_props} = delete( @props{@valid_props} );
374 warn "Unknown properties: @{[keys %props]}\n" if scalar( %props );
378 filename => $filename,
389 my $self = bless(\%data, $class);
392 $self->_parse_fh($handle);
395 $self->_parse_file();
398 unless($self->{module} and length($self->{module})) {
399 my ($v, $d, $f) = File::Spec->splitpath($self->{filename});
402 my @candidates = grep /$f$/, @{$self->{packages}};
403 $self->{module} = shift(@candidates); # punt
406 if(grep /main/, @{$self->{packages}}) {
407 $self->{module} = 'main';
410 $self->{module} = $self->{packages}[0] || '';
415 $self->{version} = $self->{versions}{$self->{module}}
416 if defined( $self->{module} );
422 sub _do_find_module {
424 my $module = shift || croak 'find_module_by_name() requires a package name';
425 my $dirs = shift || \@INC;
427 my $file = File::Spec->catfile(split( /::/, $module));
428 foreach my $dir ( @$dirs ) {
429 my $testfile = File::Spec->catfile($dir, $file);
430 return [ File::Spec->rel2abs( $testfile ), $dir ]
431 if -e $testfile and !-d _; # For stuff like ExtUtils::xsubpp
432 return [ File::Spec->rel2abs( "$testfile.pm" ), $dir ]
433 if -e "$testfile.pm";
439 sub find_module_by_name {
440 my $found = shift()->_do_find_module(@_) or return;
445 sub find_module_dir_by_name {
446 my $found = shift()->_do_find_module(@_) or return;
451 # given a line of perl code, attempt to parse it if it looks like a
452 # $VERSION assignment, returning sigil, full name, & package name
453 sub _parse_version_expression {
457 my( $sig, $var, $pkg );
458 if ( $line =~ /$VERS_REGEXP/o ) {
459 ( $sig, $var, $pkg ) = $2 ? ( $1, $2, $3 ) : ( $4, $5, $6 );
461 $pkg = ($pkg eq '::') ? 'main' : $pkg;
466 return ( $sig, $var, $pkg );
472 my $filename = $self->{filename};
473 open my $fh, '<', $filename
474 or croak( "Can't open '$filename': $!" );
476 $self->_handle_bom($fh, $filename);
478 $self->_parse_fh($fh);
481 # Look for a UTF-8/UTF-16BE/UTF-16LE BOM at the beginning of the stream.
482 # If there's one, then skip it and set the :encoding layer appropriately.
484 my ($self, $fh, $filename) = @_;
487 return unless defined $pos;
490 my $count = read $fh, $buf, length $buf;
491 return unless defined $count and $count >= 2;
494 if ( $buf eq "\x{FE}\x{FF}" ) {
495 $encoding = 'UTF-16BE';
496 } elsif ( $buf eq "\x{FF}\x{FE}" ) {
497 $encoding = 'UTF-16LE';
498 } elsif ( $buf eq "\x{EF}\x{BB}" ) {
500 $count = read $fh, $buf, length $buf;
501 if ( defined $count and $count >= 1 and $buf eq "\x{BF}" ) {
506 if ( defined $encoding ) {
507 if ( "$]" >= 5.008 ) {
508 binmode( $fh, ":encoding($encoding)" );
511 seek $fh, $pos, SEEK_SET
512 or croak( sprintf "Can't reset position to the top of '$filename'" );
519 my ($self, $fh) = @_;
521 my( $in_pod, $seen_end, $need_vers ) = ( 0, 0, 0 );
522 my( @pkgs, %vers, %pod, @pod );
528 while (defined( my $line = <$fh> )) {
533 # From toke.c : any line that begins by "=X", where X is an alphabetic
534 # character, introduces a POD segment.
536 if ( $line =~ /^=([a-zA-Z].*)/ ) {
538 # Then it goes back to Perl code for "=cutX" where X is a non-alphabetic
539 # character (which includes the newline, but here we chomped it away).
540 $is_cut = $cmd =~ /^cut(?:[^a-zA-Z]|$)/;
546 if ( $line =~ /^=head[1-4]\s+(.+)\s*$/ ) {
548 if ( $self->{collect_pod} && length( $pod_data ) ) {
549 $pod{$pod_sect} = $pod_data;
554 } elsif ( $self->{collect_pod} ) {
555 $pod_data .= "$line\n";
559 } elsif ( $is_cut ) {
561 if ( $self->{collect_pod} && length( $pod_data ) ) {
562 $pod{$pod_sect} = $pod_data;
572 # Skip comments in code
573 next if $line =~ /^\s*#/;
575 # Would be nice if we could also check $in_string or something too
576 if ($line eq '__END__') {
580 last if $line eq '__DATA__';
582 # parse $line to see if it's a $VERSION declaration
583 my( $vers_sig, $vers_fullname, $vers_pkg ) =
585 ? $self->_parse_version_expression( $line )
588 if ( $line =~ /$PKG_REGEXP/o ) {
590 push( @pkgs, $pkg ) unless grep( $pkg eq $_, @pkgs );
591 $vers{$pkg} = $2 unless exists( $vers{$pkg} );
592 $need_vers = defined $2 ? 0 : 1;
594 # VERSION defined with full package spec, i.e. $Module::VERSION
595 } elsif ( $vers_fullname && $vers_pkg ) {
596 push( @pkgs, $vers_pkg ) unless grep( $vers_pkg eq $_, @pkgs );
597 $need_vers = 0 if $vers_pkg eq $pkg;
599 unless ( defined $vers{$vers_pkg} && length $vers{$vers_pkg} ) {
601 $self->_evaluate_version_line( $vers_sig, $vers_fullname, $line );
604 # first non-comment line in undeclared package main is VERSION
605 } elsif ( !exists($vers{main}) && $pkg eq 'main' && $vers_fullname ) {
608 $self->_evaluate_version_line( $vers_sig, $vers_fullname, $line );
610 push( @pkgs, 'main' );
612 # first non-comment line in undeclared package defines package main
613 } elsif ( !exists($vers{main}) && $pkg eq 'main' && $line =~ /\w+/ ) {
616 push( @pkgs, 'main' );
618 # only keep if this is the first $VERSION seen
619 } elsif ( $vers_fullname && $need_vers ) {
622 $self->_evaluate_version_line( $vers_sig, $vers_fullname, $line );
625 unless ( defined $vers{$pkg} && length $vers{$pkg} ) {
635 if ( $self->{collect_pod} && length($pod_data) ) {
636 $pod{$pod_sect} = $pod_data;
639 $self->{versions} = \%vers;
640 $self->{packages} = \@pkgs;
641 $self->{pod} = \%pod;
642 $self->{pod_headings} = \@pod;
647 sub _evaluate_version_line {
649 my( $sigil, $var, $line ) = @_;
651 # Some of this code came from the ExtUtils:: hierarchy.
653 # We compile into $vsub because 'use version' would cause
654 # compiletime/runtime issues with local()
656 $pn++; # everybody gets their own package
657 my $eval = qq{BEGIN { q# Hide from _packages_inside()
658 #; package Module::Metadata::_version::p$pn;
671 # Try to get the $VERSION
673 # some modules say $VERSION = $Foo::Bar::VERSION, but Foo::Bar isn't
674 # installed, so we need to hunt in ./lib for it
675 if ( $@ =~ /Can't locate/ && -d 'lib' ) {
676 local @INC = ('lib',@INC);
680 warn "Error evaling version line '$eval' in $self->{filename}: $@\n"
682 (ref($vsub) eq 'CODE') or
683 croak "failed to build version sub for $self->{filename}";
684 my $result = eval { $vsub->() };
685 croak "Could not get version from $self->{filename} by executing:\n$eval\n\nThe fatal error was: $@\n"
688 # Upgrade it into a version object
689 my $version = eval { _dwim_version($result) };
691 croak "Version '$result' from $self->{filename} does not appear to be valid:\n$eval\n\nThe fatal error was: $@\n"
692 unless defined $version; # "0" is OK!
698 # Try to DWIM when things fail the lax version test in obvious ways
701 # Best case, it just works
702 sub { return shift },
704 # If we still don't have a version, try stripping any
705 # trailing junk that is prohibited by lax rules
708 $v =~ s{([0-9])[a-z-].*$}{$1}i; # 1.23-alpha or 1.23b
712 # Activestate apparently creates custom versions like '1.23_45_01', which
713 # cause version.pm to think it's an invalid alpha. So check for that
717 my $num_dots = () = $v =~ m{(\.)}g;
718 my $num_unders = () = $v =~ m{(_)}g;
719 my $leading_v = substr($v,0,1) eq 'v';
720 if ( ! $leading_v && $num_dots < 2 && $num_unders > 1 ) {
722 $num_unders = () = $v =~ m{(_)}g;
727 # Worst case, try numifying it like we would have before version objects
730 no warnings 'numeric';
737 my ($result) = shift;
739 return $result if ref($result) eq 'version';
741 my ($version, $error);
742 for my $f (@version_prep) {
743 $result = $f->($result);
744 $version = eval { version->new($result) };
745 $error ||= $@ if $@; # capture first failure
746 last if defined $version;
749 croak $error unless defined $version;
755 ############################################################
758 sub name { $_[0]->{module} }
760 sub filename { $_[0]->{filename} }
761 sub packages_inside { @{$_[0]->{packages}} }
762 sub pod_inside { @{$_[0]->{pod_headings}} }
763 sub contains_pod { 0+@{$_[0]->{pod_headings}} }
767 my $mod = shift || $self->{module};
769 if ( defined( $mod ) && length( $mod ) &&
770 exists( $self->{versions}{$mod} ) ) {
771 return $self->{versions}{$mod};
780 if ( defined( $sect ) && length( $sect ) &&
781 exists( $self->{pod}{$sect} ) ) {
782 return $self->{pod}{$sect};
792 Module::Metadata - Gather package and POD information from perl module files
796 use Module::Metadata;
798 # information about a .pm file
799 my $info = Module::Metadata->new_from_file( $file );
800 my $version = $info->version;
802 # CPAN META 'provides' field for .pm files in a directory
803 my $provides = Module::Metadata->provides(
804 dir => 'lib', version => 2
809 This module provides a standard way to gather metadata about a .pm file
810 without executing unsafe code.
818 =item C<< new_from_file($filename, collect_pod => 1) >>
820 Constructs a C<Module::Metadata> object given the path to a file. Returns
821 undef if the filename does not exist.
823 C<collect_pod> is a optional boolean argument that determines whether POD
824 data is collected and stored for reference. POD data is not collected by
825 default. POD headings are always collected.
827 If the file begins by an UTF-8, UTF-16BE or UTF-16LE byte-order mark, then
828 it is skipped before processing, and the content of the file is also decoded
829 appropriately starting from perl 5.8.
831 =item C<< new_from_handle($handle, $filename, collect_pod => 1) >>
833 This works just like C<new_from_file>, except that a handle can be provided
834 as the first argument.
836 Note that there is no validation to confirm that the handle is a handle or
837 something that can act like one. Passing something that isn't a handle will
838 cause a exception when trying to read from it. The C<filename> argument is
839 mandatory or undef will be returned.
841 You are responsible for setting the decoding layers on C<$handle> if
844 =item C<< new_from_module($module, collect_pod => 1, inc => \@dirs) >>
846 Constructs a C<Module::Metadata> object given a module or package name.
847 Returns undef if the module cannot be found.
849 In addition to accepting the C<collect_pod> argument as described above,
850 this method accepts a C<inc> argument which is a reference to an array of
851 directories to search for the module. If none are given, the default is
854 If the file that contains the module begins by an UTF-8, UTF-16BE or
855 UTF-16LE byte-order mark, then it is skipped before processing, and the
856 content of the file is also decoded appropriately starting from perl 5.8.
858 =item C<< find_module_by_name($module, \@dirs) >>
860 Returns the path to a module given the module or package name. A list
861 of directories can be passed in as an optional parameter, otherwise
864 Can be called as either an object or a class method.
866 =item C<< find_module_dir_by_name($module, \@dirs) >>
868 Returns the entry in C<@dirs> (or C<@INC> by default) that contains
869 the module C<$module>. A list of directories can be passed in as an
870 optional parameter, otherwise @INC is searched.
872 Can be called as either an object or a class method.
874 =item C<< provides( %options ) >>
876 This is a convenience wrapper around C<package_versions_from_directory>
877 to generate a CPAN META C<provides> data structure. It takes key/value
878 pairs. Valid option keys include:
882 =item version B<(required)>
884 Specifies which version of the L<CPAN::Meta::Spec> should be used as
885 the format of the C<provides> output. Currently only '1.4' and '2'
886 are supported (and their format is identical). This may change in
887 the future as the definition of C<provides> changes.
889 The C<version> option is required. If it is omitted or if
890 an unsupported version is given, then C<provides> will throw an error.
894 Directory to search recursively for F<.pm> files. May not be specified with
899 Array reference of files to examine. May not be specified with C<dir>.
903 String to prepend to the C<file> field of the resulting output. This defaults
904 to F<lib>, which is the common case for most CPAN distributions with their
905 F<.pm> files in F<lib>. This option ensures the META information has the
906 correct relative path even when the C<dir> or C<files> arguments are
907 absolute or have relative paths from a location other than the distribution
912 For example, given C<dir> of 'lib' and C<prefix> of 'lib', the return value
913 is a hashref of the form:
918 file => 'lib/Package/Name.pm'
920 'OtherPackage::Name' => ...
923 =item C<< package_versions_from_directory($dir, \@files?) >>
925 Scans C<$dir> for .pm files (unless C<@files> is given, in which case looks
926 for those files in C<$dir> - and reads each file for packages and versions,
927 returning a hashref of the form:
932 file => 'Package/Name.pm'
934 'OtherPackage::Name' => ...
937 The C<DB> and C<main> packages are always omitted, as are any "private"
938 packages that have leading underscores in the namespace (e.g.
941 Note that the file path is relative to C<$dir> if that is specified.
942 This B<must not> be used directly for CPAN META C<provides>. See
943 the C<provides> method instead.
945 =item C<< log_info (internal) >>
947 Used internally to perform logging; imported from Log::Contextual if
948 Log::Contextual has already been loaded, otherwise simply calls warn.
952 =head2 Object methods
958 Returns the name of the package represented by this module. If there
959 are more than one packages, it makes a best guess based on the
960 filename. If it's a script (i.e. not a *.pm) the package name is
963 =item C<< version($package) >>
965 Returns the version as defined by the $VERSION variable for the
966 package as returned by the C<name> method if no arguments are
967 given. If given the name of a package it will attempt to return the
968 version of that package if it is specified in the file.
970 =item C<< filename() >>
972 Returns the absolute path to the file.
974 =item C<< packages_inside() >>
976 Returns a list of packages. Note: this is a raw list of packages
977 discovered (or assumed, in the case of C<main>). It is not
978 filtered for C<DB>, C<main> or private packages the way the
979 C<provides> method does. Invalid package names are not returned,
980 for example "Foo:Bar". Strange but valid package names are
981 returned, for example "Foo::Bar::", and are left up to the caller
984 =item C<< pod_inside() >>
986 Returns a list of POD sections.
988 =item C<< contains_pod() >>
990 Returns true if there is any POD in the file.
992 =item C<< pod($section) >>
994 Returns the POD data in the given section.
1000 Original code from Module::Build::ModuleInfo by Ken Williams
1001 <kwilliams@cpan.org>, Randy W. Sims <RandyS@ThePierianSpring.org>
1003 Released as Module::Metadata by Matt S Trout (mst) <mst@shadowcat.co.uk> with
1004 assistance from David Golden (xdg) <dagolden@cpan.org>.
1006 =head1 COPYRIGHT & LICENSE
1008 Original code Copyright (c) 2001-2011 Ken Williams.
1009 Additional code Copyright (c) 2010-2011 Matt Trout and David Golden.
1010 All rights reserved.
1012 This library is free software; you can redistribute it and/or
1013 modify it under the same terms as Perl itself.