#!@@@perl@@@ -w

=head1 NAME

cleandir - remove unused files from directory

=head1 SYNOPSIS

cleandir [-d days] [-n] [-m] [-v] [-s] [-i|-x regex] directory...

=head1 DESCRIPTION

cleandir recursively searches each directory given on the commandline
for files and subdirectories which have not been accessed for n days and
deletes them. It is intended to be used on /tmp and other world-writable
directories and implements a number of checks to prevent symlink or
directory switching attacks. It also does not cross mount points.

=head1 OPTIONS

=over 4

=item B<-d days>

Delete files which have not been accessed for the given number of days.
The default is 14.

=item B<-m>

Consider only the last modification time of the file, not the last access time.

=item B<-n>

No-op. Don't delete any files.

=item B<-s>

Skip sockets and named pipes. Some programs (notably X11 and some
databases) create sockets and named pipes in /tmp and foolishly expect 
them to survive. This option exists to humour them.

=item B<-v>

Verbose. Can be repeated to increase verbosity.

=item B<-i>|B<-x> regex

Include and exclude patterns. The filenames (not the complete path) of
all files and directories to be removed are compared against these
patterns in order. The first hit determines the action. These patterns
can also be used to override the -s option and to cross mount points.

=back

=head1 AUTHOR

Peter J. Holzer <hjp@hjp.at>. Thanks to Chris Mason for some
enhancements.

=cut

use strict;
use File::stat;
use POSIX;
use Getopt::Long;
use Pod::Usage;

my $verbose = 0;
my $nop = 0;
my $skip_fifos = 0;
my $mtime_only = 0;


sub cleandir {
    my ($dir, $since, $level, $inex) = (@_);
    my $notremoved = 0;

    if ($verbose > 1) {
	print STDERR "$0:", " " x $level, " cleandir $dir $since {\n";
    }
    if (!opendir(DIR, ".")) {
	printf STDERR "$0:", " " x $level, " cannot opendir $dir: $!";
	return;
    }
    my $std = lstat(".");
    my $fs = $std->dev;

    for my $i (readdir(DIR)) {
	if ($i eq "." || $i eq "..") {next}
	if ($verbose > 2) {
	    print STDERR "$0:", " " x $level, " checking $dir/$i\n";
	}
	my $st = lstat("$i");

	my $action = 'i';
	# Skip anything on a different filesystem
	if ($st->dev != $fs) {
		$action = 'x';
	}

	# Skip sockets and pipes
	if ($skip_fifos && (-p _ || -S _)) {
		$action = 'x';
	}

	for (@$inex) {
	    if ($i =~ /$_->[0]/) {
		$action = $_->[1];
		last;
	    }
	}
	if ($action eq 'x') {
		$notremoved++;
		next;
	}

	if ($verbose > 3) {
	    print STDERR "$0:", " " x $level, " mtime=", $st->mtime, " atime=", $st->atime, "\n";
	}
	if (-d _) {
	    my $cwd = getcwd();
	    if (chdir($i)) {
		my $remaining = -1;
		my $st1 = lstat(".");
		if ($st->dev == $st1->dev && $st->ino == $st1->ino) {
		    $remaining = cleandir("$dir/$i", $since, $level+1, $inex);
		} else {
		    print STDERR "$0:", " " x $level,
		    		 " $dir/$i changed dev/inode from ",
				 $st->dev, "/", $st->ino,
				 " to ",
				 $st1->dev, "/", $st1->ino,
				 "\n";
		}
		chdir($cwd);
		my $std1 = lstat(".");
		if (!($std->dev == $std1->dev && $std->ino == $std1->ino)) {
		    print STDERR "$0:", " " x $level,
		    		 " $cwd changed dev/inode from ",
				 $std->dev, "/", $std->ino,
				 " to ",
				 $std1->dev, "/", $std1->ino,
				 "\n";
		    return ++$notremoved;
		}
		if ($remaining == 0 && $st->mtime < $since) {
		    if ($verbose > 0) {
			print STDERR "$0:", " " x $level, "rmdir $dir/$i\n";
		    }
		    unless ($nop) {
			if (rmdir("$i")) {next}
			print STDERR "$0:", " " x $level, "rmdir $dir/$i failed: $!\n";
		    }
		} 
	    } else {
		print STDERR "$0:", " " x $level, " chdir $dir/$i failed: $!\n";
	    }
	    
	} elsif ($st->mtime < $since && ($st->atime < $since || $mtime_only)) {
	    if ($verbose > 0) {
		print STDERR "$0:", " " x $level, " removing $dir/$i\n";
	    }
	    unless ($nop) {
		if (unlink("$i")) {next}
		print STDERR "$0:", " " x $level, " removing $dir/$i failed: $!\n";
	    }
	} 
	$notremoved++;
    }
    if ($verbose > 1) {
	print STDERR "$0:", " " x $level, " cleandir: $notremoved }\n";
    }
    return $notremoved;
}

sub main {
    my $since = time() - 14 * 86400;;
    my $help;
    my @inex;

    GetOptions('help|?' => \$help,
               'days|d=f' => sub { $since = time() - $_[1] * 86400; },
               'verbose|v' => sub { $verbose++ },
	       'nop|n' => \$nop,
	       'skip-fifos|s' => \$skip_fifos,
	       'mtime-only|m' => \$mtime_only,
	       'include|i=s' => sub { push @inex, [ $_[1], 'i' ] },
	       'exclude|x=s' => sub { push @inex, [ $_[1], 'x' ] },
	      ) or pod2usage(2);
    pod2usage(1) if $help;
    pod2usage(2) unless (@ARGV);
    

    while (my $i = shift(@ARGV)) {
	my $cwd = getcwd();
	if (chdir($i)) {
	    cleandir($i, $since, 0, \@inex);
	    chdir($cwd);
	}
    }
    exit(0);
}

main();

# $Log: cleandir.pl,v $
# Revision 1.9  2006-08-25 09:57:10  hjp
# Added --include (-i) and --exclude (-x) options.
#
# Revision 1.8  2005/04/04 16:05:40  hjp
# Print whole directory at rmdir with verbose output.
#
# Revision 1.7  2004/11/02 09:01:12  hjp
# Critical bug fix: Empty directories were removed even with -n.
# Minor cleanup: Message "removing ..." is now the same with and without -n.
#
# Revision 1.6  2003/05/16 14:44:58  hjp
# Added -m option to synopsis.
#
# Revision 1.5  2003/05/16 13:38:25  hjp
# Included -m (mtime-only) option (CVS is nice, but only if it used).
# Improved pod a bit.
#
# Revision 1.4  2003/05/15 10:49:33  hjp
# Changed tests on skip_fifo to use _ instead of $i. The latter caused
# extra calls to stat which clobbered the state of _ which caused spurious
# errors/warnings on symlinks.
#
# Revision 1.3  2003/05/14 11:49:56  hjp
# Added yet another patch by Chris Mason.
#
# Added POD.
#
# Changed option processing to use Getopt::Long and Pod::Usage.
#
# Revision 1.2  2002/02/25 23:33:29  hjp
# Applied patch from "Chris L. Mason" <cmason@somanetworks.com> to prevent
# filesystem traversal.
#
# Return immediately if we cannot chdir back to the directory we came
# from.
#
# Revision 1.1  2001/06/25 17:55:03  hjp
# Added configure script to figure out perl location.
#
# Revision 1.4  2000/11/20 21:10:08  hjp
# Checks introduced in last version prevented deletion of unused subdirs.
# Fixed.
#
# revision 1.3
# date: 2000/09/10 16:16:41;  author: hjp;  state: Exp;  lines: +37 -6
# Added checks to detect directory/symlink switching attacks.
# ----------------------------
# revision 1.2
# date: 1999/08/21 12:37:53;  author: hjp;  state: Exp;  lines: +25 -13
# More levels of verbosity.
# ----------------------------
# revision 1.1
# date: 1999/07/09 21:05:26;  author: hjp;  state: Exp;
# Added cleandir
#