+=head2 C<version_c2g $version>
+
+Converts a CPAN version to a Gentoo version.
+
+=cut
+
+sub version_c2g {
+ my ($v) = @_;
+
+ $v =~ y/-/_/;
+ $v =~ y/0-9._//cd;
+
+ $v =~ s/^[._]*//;
+ $v =~ s/[._]*$//;
+ $v =~ s/([._])[._]*/$1/g;
+
+ ($v, my $patch, my @rest) = split /_/, $v;
+ $v .= '_p' . $patch if defined $patch;
+ $v .= join('.', '', @rest) if @rest;
+
+ return $v;
+}
+
+=head2 C<version_gcmp $va, $vb>
+
+Compares two Gentoo versions.
+
+=cut
+
+sub version_gcmp {
+ my ($a, $b) = map { defined() ? $_ : 0 } @_;
+
+ for ($a, $b) {
+ s/^[._]+//g;
+ s/[._]+$//g;
+ if (/^([\d.]*\d)\.*(?:_p\.*(\d[\d.]*))?\.*(?:-r(\d+))?$/) {
+ $_ = {
+ v => [ split /\.+/, $1 ],
+ p => [ split /\.+/, $2 || 0 ],
+ r => [ $3 || 0 ],
+ };
+ } else {
+ require Carp;
+ Carp::croak("Couldn't parse version string '$_'");
+ }
+ }
+
+ for my $k (qw/v p r/) {
+ my $xa = $a->{$k};
+ my $xb = $b->{$k};
+ while (@$xa or @$xb) {
+ my $na = shift(@$xa) || 0;
+ my $nb = shift(@$xb) || 0;
+ my $c = $na <=> $nb;
+ return $c if $c;
+ }
+ }
+
+ return 0;
+}
+