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=head1 NAME |
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|
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Net::FCP::Metadata - metadata utility class. |
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|
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=head1 SYNOPSIS |
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|
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use Net::FCP::Metadata; |
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|
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=head1 DESCRIPTION |
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|
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=over 4 |
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|
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=cut |
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|
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package Net::FCP::Metadata; |
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|
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use Carp (); |
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|
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use Net::FCP::Util qw(tolc touc xeh); |
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|
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no warnings; |
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|
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use overload |
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'""' => sub { $_[0]->as_string }; |
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|
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=item $metadata = new Net::FCP::Metadata [$string_or_object] |
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|
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Creates a new metadata Object from the given string or reference. The |
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object is overloaded and will stringify into the corresponding string form |
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(which might be slightly different than the string it was created from). |
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|
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If no arguments is given, creates a new metadata object with just a |
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C<version> part. |
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|
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The object is implemented as a hash reference. See C<parse_metadata>, |
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below, for info on it's structure. |
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|
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=cut |
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|
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sub new { |
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my ($class, $data) = @_; |
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|
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$data = ref $data ? %$data |
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: $data ? parse_metadata ($data) |
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: { version => { revision => 1 } }; |
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|
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bless $data, $class; |
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} |
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|
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=item $metadata->as_string |
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|
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Returns the string form of the metadata data. |
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|
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=cut |
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|
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sub as_string { |
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build_metadata ($_[0]); |
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} |
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|
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=item $metadata->add_redirect ($name, $target[ info1 => arg1...]) |
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|
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Add a simple redirection to the C<document> section to the given |
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target. All extra arguments will be added to the C<info> subsection and |
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often contains C<description> and C<format> fields. |
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|
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=cut |
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|
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sub add_redirect { |
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my ($self, $name, $target, %info) = @_; |
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|
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push @{ $self->{document} }, { |
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redirect => { target => $target }, |
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$name ? (name => $name) : (), |
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%info ? (info => \%info) : (), |
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}; |
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} |
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|
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=item $meta = Net::FCP::Metadata::parse_metadata $string |
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|
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Internal utility function, do not use directly! |
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|
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Parse a metadata string and return it. |
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|
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The metadata will be a hashref with key C<version> (containing the |
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mandatory version header entries) and key C<raw> containing the original |
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metadata string. |
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|
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All other headers are represented by arrayrefs (they can be repeated). |
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|
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Since this description is confusing, here is a rather verbose example of a |
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parsed manifest: |
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|
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( |
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raw => "Version...", |
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version => { revision => 1 }, |
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document => [ |
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{ |
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info => { format" => "image/jpeg" }, |
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name => "background.jpg", |
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redirect => { target => "freenet:CHK\@ZcagI,ra726bSw" }, |
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}, |
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{ |
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info => { format" => "text/html" }, |
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name => ".next", |
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redirect => { target => "freenet:SSK\@ilUPAgM/TFEE/3" }, |
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}, |
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{ |
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info => { format" => "text/html" }, |
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redirect => { target => "freenet:CHK\@8M8Po8ucwI,8xA" }, |
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} |
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] |
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) |
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|
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=cut |
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|
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sub parse_metadata { |
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my $data = shift; |
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my $meta = { raw => $data }; |
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|
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if ($data =~ /^Version\015?\012/gc) { |
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my $hdr = $meta->{version} = {}; |
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|
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for (;;) { |
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while ($data =~ /\G([^=\015\012]+)=([^\015\012]*)\015?\012/gc) { |
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my ($k, $v) = ($1, $2); |
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my @p = split /\./, tolc $k, 3; |
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|
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$hdr->{$p[0]} = $v if @p == 1; # lamest code I ever wrote |
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$hdr->{$p[0]}{$p[1]} = $v if @p == 2; |
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$hdr->{$p[0]}{$p[1]}{$p[2]} = $v if @p == 3; |
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die "FATAL: 4+ dot metadata" if @p >= 4; |
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} |
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|
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if ($data =~ /\GEndPart\015?\012/gc) { |
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# nop |
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} elsif ($data =~ /\GEnd(\015?\012|$)/gc) { |
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last; |
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} elsif ($data =~ /\G([A-Za-z0-9.\-]+)\015?\012/gcs) { |
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push @{$meta->{tolc $1}}, $hdr = {}; |
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} elsif ($data =~ /\G(.*)/gcs) { |
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print STDERR "metadata format error ($1), please report this string: <<$data>>"; |
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die "metadata format error"; |
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} |
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} |
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} |
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|
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#$meta->{tail} = substr $data, pos $data; |
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|
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$meta; |
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} |
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|
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=item $string = Net::FCP::Metadata::build_metadata $meta |
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|
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Internal utility function, do not use directly! |
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|
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Takes a hash reference as returned by C<Net::FCP::parse_metadata> and |
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returns the corresponding string form. If a string is given, it's returned |
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as is. |
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|
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=cut |
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|
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sub build_metadata_subhash($$$) { |
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my ($prefix, $level, $hash) = @_; |
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|
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join "", |
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map |
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ref $hash->{$_} ? build_metadata_subhash ($prefix . (Net::FCP::touc $_) . ".", $level + 1, $hash->{$_}) |
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: $prefix . ($level > 1 ? $_ : Net::FCP::touc $_) . "=" . $hash->{$_} . "\n", |
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keys %$hash; |
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} |
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|
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sub build_metadata_hash($$) { |
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my ($header, $hash) = @_; |
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|
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if (ref $hash eq ARRAY::) { |
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join "", map build_metadata_hash ($header, $_), @$hash |
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} else { |
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(Net::FCP::touc $header) . "\n" |
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. (build_metadata_subhash "", 0, $hash) |
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. "EndPart\n"; |
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} |
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} |
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|
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sub build_metadata($) { |
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my ($meta) = @_; |
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|
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return $meta unless ref $meta; |
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|
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$meta = { %$meta }; |
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|
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delete $meta->{raw}; |
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|
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my $res = |
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(build_metadata_hash version => delete $meta->{version}) |
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. (join "", map +(build_metadata_hash $_, $meta->{$_}), keys %$meta); |
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|
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substr $res, -5, 4, ""; # get rid of "Part". Broken Syntax.... |
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|
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$res; |
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} |
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|
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=back |
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|
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=head1 SEE ALSO |
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|
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L<Net::FCP>. |
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|
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=head1 BUGS |
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|
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Not heavily tested. |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <pcg@goof.com> |
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http://www.goof.com/pcg/marc/ |
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|
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=cut |
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|
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1; |
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|
