#!/bin/bash

# zipdir - shrink specified directories.
# Copyright © 2000-2009 by Pádraig Brady <P@draigBrady.com>.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU General Public License for more details,
# which is available at www.gnu.org


# Notes:
#
# Note only directories
# on ext[23] filesystems will be processed at present.
# Note this is required as ext[23] does not deallocate
# directory blocks as they are no longer required.
# As well as taking disk space, it also makes lookups
# in the directory take longer. It would make sense
# to run this as root @ system startup, at the same
# time as fsck? It would be safer to run in single user
# mode since there is a "small" window where data is
# not in a directory when a running process goes to
# look for it. Hmm I guess if there are any extended
# attributes cpio will not copy them?

script_dir=`dirname "$0"`              #directory of this script
script_dir=`readlink -f "$script_dir"` #Make sure absolute path

. "$script_dir"/supprt/fslver

Usage() {
	ProgName=`basename "$0"`
	echo "Shrink Directories.
Usage: $ProgName [[-r] paths(s) ...]

NB make sure that you don't process directories that are
being referenced by running processes, as this utility
will move directories from their current locations (for
a "small" amount of time). Run only in single user mode
if you are not sure of the consequences.

If no path(s) specified then the currrent directory is assumed."
	exit
}

for arg
do
	case "$arg" in
	-h|--help|-help)
		Usage ;;
	-v|--version)
		Version ;;
	*)
		argsToPassOn="$argsToPassOn $(shell_quote "$arg")" ;;
	esac
done

if [ `id -u` != "0" ]; then #Only allow root so don't worry about permissions...
	echo "Sorry, root permission is required." >&2; exit 1
fi

cpio --version > /dev/null 2>&1 || \
{ echo "Sorry, cpio is required." >&2; exit 1; }

ESC=`printf "\x1b["`

#check we have an adequate mv
mvStatus=good
rm -Rf /tmp/fslint2
mkdir /tmp/fslint1 /tmp/fslint2 2> /dev/null
mv -f --target-directory=/tmp/fslint2 /tmp/fslint1 2> /dev/null || mvStatus=bad
rm -Rf /tmp/fslint2

if [ $mvStatus = "bad" ]
then
	echo "Sorry, you need a newer GNU fileutils"
	exit
fi

set -f #no globbing
. "$script_dir"/supprt/getfpf -f "$argsToPassOn" #Force absolute path mode

#Sanity checks in case user specifies any of these
#can't process /bin as mv & rmdir here
bin=`find /bin -maxdepth 0 -printf "%i"`
#can't process /lib as mv & rmdir need libc here
lin=`find /lib -maxdepth 0 -printf "%i"`
#can't process /dev as it'll break :-)
din=`find /dev -maxdepth 0 -printf "%i"`
#not sure about this, better leave alone
lfin=`find /lost+found -maxdepth 0 -printf "%i"`
#inode of all mount points is 1, and obviously can't move mount points
mntin="1"

export totalSavedBytes=0

find $findArgs -type d -size +2b -depth \( -fstype ext2 -o -fstype ext3 \) \
-xdev \( ! -inum $bin ! -inum $lin ! -inum $din ! -inum $lfin ! -inum $mntin \) \
-printf "$FPF\n" |
tr ' \t' '\1\2' | #TODO: should also use sed to escape shell chars
while read
do
	dir=$(echo "$REPLY" | tr '\1\2' ' \t')
	find "$dir" -maxdepth 0 -printf "%7s -> "

	origsize=`find "$dir" -maxdepth 0 -printf "%s"`

	basedir=`basename "$dir"`
	basepath=`dirname "$dir"`
	tmpdir=fslint.shrink
	tmpnewdir=$tmpdir/"$basedir"

	cd "$basepath"
	mkdir $tmpdir #make here as same device
	echo "$basedir" | cpio -pam $tmpdir 2> /dev/null
	find "$basedir" -maxdepth 1 -mindepth 1 -print0 |
	xargs -r0 mv -f --target-directory="$tmpnewdir"
	#mv -f "$basedir"/* "$tmpnewdir"
	rmdir "$basedir"
	mv "$tmpnewdir" "$basedir"
	rmdir $tmpdir
	cd -

	new_size=`find "$dir" -maxdepth 0 -printf "%s"`
	diffsize=`expr $origsize - $new_size`
	if [ $diffsize != "0" ]
	then
	   find "$dir" -maxdepth 0 -printf "${ESC}31m%7s${ESC}0m (bytes) %p\n"
	   #how to echo the following @ the end?
	   totalSavedBytes=`expr $diffsize + $totalSavedBytes`
	else
	   find "$dir" -maxdepth 0 -printf "%7s (bytes) %p\n"
	fi
done