#!/bin/bash
# $Header: /CVSROOT/dirlist/cmpanddel.sh,v 1.3 2008-05-25 23:56:50 tino Exp $
#
# Compare directory with a second and delete files which match.
#
# Copyright (C)2006 by Valentin Hilbig
#
# 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 (at your option) 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.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA
#
# $Log: cmpanddel.sh,v $
# Revision 1.3  2008-05-25 23:56:50  tino
# Minor output fixes in certain situations
#
# Revision 1.2  2007-10-01 16:21:17  tino
# Made more readable
#
# Revision 1.1  2006-11-07 12:41:20  tino
# cmpanddel.sh added

set -e

oops()
{
echo "$*" >&2
exit 1
}

maketmpdir()
{
if [ -n "$1" ]
then
	tmpdir="$1"
	[ ! -d "$1" ] && mkdir "$1"
else
	tmpdir="`mktemp -d tmpcmp.XXXXXX`"
fi

pf="$tmpdir/file"
pl="$tmpdir/location"
trap '[ -e "$pf" ] || rm -f "$pl"; rmdir "$tmpdir"' 0
}

usage()
{
[ 2 = $# -o 3 = $# ] ||
oops "Usage: `basename "$0"` directory-to-cleanup directory-to-compare [tmpdirname]"
}

warn()
{
el="`tput el || :``tput cr || :`"
SRC="$1"
DST="$2"
cat <<EOF

This script is for lazy experienced sysadmins and comes with mvatom:
http://www.scylla-charybdis.com/tool.php?tool=mvatom

This script removes files from the first directory which match files
in the second directory.  It checks softlinks, too.  Be sure that the
directory to delete is quiescent, this is, nobody else modifies files
or changes anything.  Also never run two of this scripts in parallel
on the same directory, you have been warned!

If this script fails have a look in the tempdir created, there are two
entries, "file" and "location".  Location tells you where file came
from.  Move it back manually.  (No warranty.  Use at own risk.  etc.)

Deletes  from "$SRC"
Compares from "$DST"

EOF
echo -n "Press return to continue: "
read
}

prot()
{
[ ! -e "$pf" ] || oops "internal error: $pf exists"

echo "$1" > "$pl"
mvatom "$1" "$pf"
unpf="$1"
}

unp()
{
[ -n "$unpf" ] || oops "internal error: variable not set"
[ ! -e "$unpf" ] || oops "internal error: $unpf exists"
[ ".$unpf" = ".`cat "$pl"`" ] || oops "internal error: $unpf does not match $pl"

mvatom "$pf" "$unpf"
unpf=""
}

show()
{
x="$(( ${#2}<70 ? 0 : ${#2}-70 ))"
echo -n "$1 ${2:$x}$el"
}

getlink()
{
find "$1" -type d -prune -o -type l -printf "%l\n"
}

cmpsoftlink()
{
show "link" "$1"

if [ ! -L "$DST/$1" ]
then
	if [ -e "$DST/$1" ]
	then
		echo "$DST/$1 is no soflink!"
	else
		echo "$DST/$1 does not exist"
	fi
	return
fi

prot "$SRC/$1"

b="`getlink "$pf"`"
c="`getlink "$DST/$1"`"
if [ ".$b" != ".$c" ]
then
	unp
	echo "$DST/$1: softlinks mismatch: $SRC/$1"
	return
fi

rm -f "$pf"
unpf=""
}

cmpfile()
{
show "file" "$1"

if [ ! -e "$DST/$1" ]
then
	echo "$DST/$1 does not exist"
	return
fi

prot "$SRC/$1"

if [ -L "$DST/$1" -o ! -f "$DST/$1" ]
then
	unp
	echo "$DST/$1 is no normal file!"
	return
fi

if ! cmp "$pf" "$DST/$1"
then
	echo "$SRC/$1 mismatch."
	unp
	return
fi

rm -f "$pf"
unpf=""
}

cmpdir()
{
show "dir " "$1"

if [ ! -e "$DST/$1" ]
then
	echo "$DST/$1 does not exist"
	return
fi

prot "$SRC/$1"

if [ -L "$DST/$1" -o ! -d "$DST/$1" ]
then
	unp
	echo "$DST/$1 is no directory!"
	return
fi

if ! rmdir "$pf"
then
	unp
	echo "$pf not empty"
	return
fi
unpf=""
}

usage "$@"
warn "$1" "$2"
maketmpdir "$3"

find "$SRC" -type f -printf "%P\n" -o -type d -name "$tmpdir" -prune |
while read -r a
do
	cmpfile "$a"
done

find "$SRC" -type l -printf "%P\n" -o -type d -name "$tmpdir" -prune |
while read -r a
do
	cmpsoftlink "$a"
done

find "$SRC" -depth -type d -name "$tmpdir" -prune -o -type d -printf "%P\n" |
while read -r a
do
	[ -z "$a" ] || cmpdir "$a"
done