#!/usr/bin/perl

=head1 NAME

dh_usrlocal - migrate usr/local directories to maintainer scripts

=cut

use warnings;
use strict;
use Debian::Debhelper::Dh_Lib;
use File::Find;
use File::stat;

=head1 SYNOPSIS

B<dh_usrlocal> [S<I<debhelper options>>] [B<-n>]

=head1 DESCRIPTION

B<dh_usrlocal> is a debhelper program that can be used for building packages
that will provide a subdirectory in F</usr/local> when installed.

It finds subdirectories of F<usr/local> in the package build directory, and
removes them, replacing them with maintainer script snippets (unless B<-n>
is used) to create the directories at install time, and remove them when
the package is removed, in a manner compliant with Debian policy. These
snippets are inserted into the maintainer scripts by B<dh_installdeb>. See
L<dh_installdeb(1)> for an explanation of debhelper maintainer script
snippets.

If the directories found in the build tree have unusual owners, groups, or
permissions, then those values will be preserved in the directories made by
the F<postinst> script. However, as a special exception, if a directory is owned
by root.root, it will be treated as if it is owned by root.staff and is mode
2775. This is useful, since that is the group and mode policy recommends for
directories in F</usr/local>.

=head1 OPTIONS

=over 4

=item B<-n>, B<--noscripts>

Do not modify F<postinst>/F<prerm> scripts.

=back

=head1 NOTES

Note that this command is not idempotent. L<dh_prep(1)> should be called
between invocations of this command. Otherwise, it may cause multiple
instances of the same text to be added to maintainer scripts.

=head1 CONFORMS TO

Debian policy, version 2.2

=cut

init();

# PROMISE: DH NOOP WITHOUT tmp(usr/local)

foreach my $package (@{$dh{DOPACKAGES}}) {
	my $tmp = tmpdir($package);

	if (-d "$tmp/usr/local") {
		my (@dirs, @justdirs);
		find({bydepth => 1,
		      no_chdir => 1,
		      wanted => sub {
			my $fn = $File::Find::name;
			if (-d $fn) {
				my $stat = stat $fn;
				my $user = getpwuid $stat->uid;
				my $group = getgrgid $stat->gid;
				my $mode = sprintf "%04lo", ($stat->mode & 07777);

				if ($stat->uid == 0 && $stat->gid == 0) {
					$group = 'staff';
					$mode = '2775';
				}

				$fn =~ s!^\Q$tmp\E!!;
				return if $fn eq '/usr/local';
				
				# @dirs is in parents-first order for dir creation...
				unshift @dirs, "$fn $mode $user $group";
				# ...whereas @justdirs is depth-first for removal.
				push @justdirs, $fn;
				doit("rmdir $_");
			}
			else {
				warning("$fn is not a directory");
			}
		      }}, "$tmp/usr/local");
		doit("rmdir $tmp/usr/local");
	
		my $bs = "\\";     # A single plain backslash
		my $ebs = $bs x 2; # Escape the backslash from the shell
		# This constructs the body of a 'sed' c\ expression which
		# is parsed by the shell in double-quotes
		my $dirs = join("$ebs\n", sort @dirs);
		pop @justdirs; # don't remove directories directly in /usr/local
		my $justdirs = join("$ebs\n", sort @justdirs);
		if (! $dh{NOSCRIPTS}) { 
			autoscript($package,"postinst", "postinst-usrlocal",
				   "/#DIRS#/ c${ebs}\n${dirs}");
			autoscript($package,"prerm", "prerm-usrlocal",
				   "/#JUSTDIRS#/ c${ebs}\n${justdirs}") if length $justdirs;
		}
	}
}

=head1 SEE ALSO

L<debhelper(7)>

This program is a part of debhelper.

=head1 AUTHOR

Andrew Stribblehill <ads@debian.org>

=cut

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