#!/usr/bin/perl -w

($SELF = $0) =~ s,.*/,,;
if(@ARGV) {
	print <<EOF;
$SELF - find installed SBo packages that are not in the SBo repo

Usage: $SELF

Output is a list of installed SBo packages that are not listed on the
SBo site. Usually this means the builds were removed from the repo,
but if you are a SBo developer, it could also find builds that you
never got around to submitting to SBo.

If any removed builds are found, and they're software you actually
use and care about, you should resubmit them to SlackBuilds.org, with
yourself as the maintainer. You can get the last version of a removed
build from: https://slackware.uk/~urchlay/boneyard/

Exit status is 0 (success) if no removed packages are installed
(if there is no output), or 1 (failure) if any removed packages are
installed.

By default, the 15.0 repo is searched, but you can export
SLACKVER in the environment to check a different version.

To use an alternate package database directory (other than
/var/log/packages), set PKGDIR in the environment.
EOF
	exit 0;
}

# TODO: get this from /etc/slackware-version or /etc/os-release
$SLACKVER = $ENV{SLACKVER} || "15.0";

# use the .gz version, saves a lot of bandwidth
$URL = "https://slackbuilds.org/slackbuilds/$SLACKVER/SLACKBUILDS.TXT.gz";

$PKGDIR = $ENV{PKGDIR} || "/var/log/packages";
chdir $PKGDIR || die "can't cd to $PKGDIR: $!\n";

for(<*_SBo>) {
	my $r = reverse;
	my @a = split /-/, $r, 4;
	my $pkg = reverse $a[3];
	$installed{$pkg}++;
}

open my $pipe, "wget -qO- $URL | gzip -dc |" or die $!;
while(<$pipe>) {
	chomp;
	next unless m{^SLACKBUILD NAME: (.*)$};
	$in_repo{$1}++;
}
close $pipe;

$count = 0;
for(sort keys %installed) {
	$count++, print "$_\n" unless $in_repo{$_};
}

exit ($count != 0);