#!/opt/default/bin/perl

# Netapps have snapshots, which cause a lot of problem for du and the output
# from du is the snapshots + diskusage from user. This program excludes 
# snapshots by defaults from the diskusage output

# options are
#		-k	will cause du to express all block counts in terms of 1024 byte blocks
#		-s	causes only the grand total of the names to be printed 
#		-x	<pattern> excludes files/dirs matching <pattern> to be excluded from
#									disk usage accounting.

# written by: Rajeev Agrawala x7473 rajeeva@research.bell-labs.com
# March 27, 1998

# March 30, 1998
# Added following options
#	
#	-a	display all files
#	-l	Compute diskusage for the same file system i.e don't descend dir if
#			file system changes
#	-r	complain about dir/files which could not be opened. default is silent.

#	April 1, 1998
#	Added following option
#
#	-h	display usage help

use Getopt::Std;

if (! getopts('ahklrsx:'))
{
	&printusage();
	exit(1);
}
if ($opt_h)
{
	&printusage();
	exit(0);
}

if (! @ARGV )
{
	@ARGV=(".");
}
if (! $opt_x)
{
	$opt_x="^\.snapshot\$";
}

foreach $entry (@ARGV)
{
	undef (%inodes);
	undef $filesystem;
	next if ! -d $entry;
	next if ($opt_x && ($entry =~ /$opt_x/));
	$total=&printdir($entry);
	if ($opt_s)
	{
		&printline($entry,$total);
	}
}
exit(0);

sub printdir
{
	my $dirtoprint=$_[0];
	my $totalblocks=0;
	local *DIRHANDLE;
	my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks) = lstat $dirtoprint;
	if ($ERRNO != 0)
	{
		print "$dirtoprint: $!\n" if $opt_r;
		return 0;
	}
	if ($opt_l)
	{
		if (defined $filesystem)
		{
			if ($dev != $filesystem)
			{
				return 0;
			}
		}
		else
		{
			$filesystem=$dev;
		}
	}
	if (! opendir DIRHANDLE,$dirtoprint)
	{
		print "$dirtoprint: $!\n" if $opt_r;
		return 0;
	}
	my @allfiles=readdir DIRHANDLE;
	foreach $file (@allfiles)
	{
		next if $file =~ /^\.$/;
		next if $file =~ /^\.\.$/;
		if ($opt_x)
		{
			next if $file =~ /$opt_x/;
		}
		$file = "$dirtoprint/$file";
		my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks) = lstat $file;
		if ($ERRNO != 0)
		{
			print "$file: $!\n" if $opt_r;
			next;
		}
		if ((-d $file) and (! -l $file))
		{
			$totalblocks += printdir ($file);
			next;
		}
		if ($nlink > 1)
		{
			if ($inodes{"$dev$ino"})
			{
				next;
			}
			else
			{
				$inodes{"$dev$ino"} = 1;
			}
		}
		$totalblocks += $blocks;
		if ($opt_a)
		{
			&printline($file,$blocks);
		}
	}
	closedir DIRHANDLE;
	my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks) = lstat $dirtoprint;
	$totalblocks += $blocks;
	if (! $opt_s)
	{
		&printline($dirtoprint,$totalblocks);
	}
	return $totalblocks;
}

sub printline()
{
	my $filetoprint=$_[0];
	my $sizetoprint=$_[1];
	$sizetoprint /= 2 if $opt_k;
	print "$sizetoprint\t$filetoprint\n";
}

sub printusage()
{
	print "usage: du [-ahklrs] [-x <pattern for files to exclude>] [<filesystem> ...]\n\n";
	print "\t-a\tdisplay all files\n\n";
	print "\t-h\tPrint this usage info\n\n";
	print "\t-k\twill cause du to express all block counts in terms of \n\t\t1024 byte blocks. Default is 512 bytes.\n\n";
	print "\t-l\tCompute diskusage for the same file system i.e don't\n\t\tdon't descend dir if file system changes.\n\n";
	print "\t-r\tcomplain about dir/files which could not be opened.\n\t\tDefault is silent.\n\n";
	print "\t-s\tcauses only the grand total of the names to be printed \n\n";
	print "\t-x <pattern> excludes files/dirs matching <pattern> to be excluded from\n\t\tdisk usage accounting.\n\n";
}