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#!/usr/bin/env perl
## Copyright © 2008-2009 by Daniel Friesel <derf@derf.homelinux.org>
## License: WTFPL <http://sam.zoy.org/wtfpl>
use strict;
use warnings;
use 5.010;
use AptPkg::Cache;
use Getopt::Long;
my $cache = AptPkg::Cache->new;
my $max_depth = 5;
my $all = 0;
my $tabsign = "\t";
my @deptypes = qw/Depends Recommends Suggests/;
my @known;
sub revdeps {
my $name = shift;
my $package = $cache->{$name};
my @return;
my $rdeps = $package->{RevDependsList};
foreach my $dependency ( @{$rdeps} ) {
if (
not $dependency->{ParentPkg}{Name} ~~ @known
and ( $all
or $cache->{ $dependency->{ParentPkg}{Name} }->{CurrentState} eq
'Installed' )
and "$dependency->{DepType}" ~~ @deptypes
)
{
push( @return, $dependency->{ParentPkg}{Name} );
}
}
push( @known, @return );
return (@return);
}
sub recurse {
my $name = shift;
my $depth = (shift) + 1;
printf( "%s%s\n", $tabsign x ( $depth - 1 ), $name );
if ( $depth >= $max_depth ) {
return;
}
foreach ( revdeps($name) ) {
recurse( $_, $depth );
}
return;
}
GetOptions(
'all!' => \$all,
'deptype=s' => sub { @deptypes = split( /,/, $_[1] ) },
'depth=i' => \$max_depth,
'tabwidth=i' => sub { $tabsign = q{ } x $_[1] },
'h|?|help' =>
sub { exec( 'perldoc', '-F', $0 ) or die("See perldoc -F $0\n") },
);
my $packagename = shift
or die("Usage: $0 [options] <package>; see $0 --help\n");
if ( not defined $cache->{$packagename} ) {
die("No such package: $packagename\n");
}
if ( $cache->{$packagename}->{Flags} =~ /Essential/ ) {
print "Essential: Yes\n";
}
recurse( $packagename, 0 );
__END__
=head1 NAME
apt-why - filtered reverse dependency displayer using AptPkg::Cache
=head1 SYNOPSIS
B<apt-why> [ I<options> ] I<package>
=head1 DESCRIPTION
B<apt-why> recursively displays I<package>'s reverse dependencies, thus
showing which installed packages require I<package> on the system.
=head1 OPTIONS
=over
=item B<--all>
Consider all packages, not just installed ones
=item B<--depth>=I<integer> (default: 5)
Specify the maximum recursion depth
=item B<--deptype>=I<types>
Only show reverse dependencies which mach the specified I<types> (comma separated list).
Right now, possible types are Depends, Suggests, Recommends.
=item B<--tabwidth>=I<i>
Indent each recursion level with I<i> spaces (by default: one tab)
=back
=head1 EXIT STATUS
Zero on success, non-zero on error (i.e. no such package).
=head1 CONFIGURATION
None.
=head1 DEPENDENCIES
This program requires the perl module B<AptPkg::Cache>. On Debian, it is
available via the package B<libapt-pkg-perl>.
=head1 BUGS AND LIMITATIONS
There may be problems with virtual packages and "Provides: " stuff.
=head1 AUTHOR
Daniel Friesel E<lt>derf@derf.homelinux.orgE<gt>
=head1 LICENSE
0. You just DO WHAT THE FUCK YOU WANT TO.
|
