#! /bin/bash
# Extract names of new files from a patch, print them out

#  This script is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License version 2 as
#  published by the Free Software Foundation.
#
#  See the COPYING and AUTHORS files for more details.

usage()
{
	echo "Usage: touched-by-patch [-p num] patchname"
	exit 1
}

options=`getopt -o p:h -- "$@"`

if [ $? -ne 0 ]
then
	usage
fi

eval set -- "$options"

while true
do
	case "$1" in
	-p)
		opt_p=$2
		shift 2 ;;
	-h)
		usage ;;
	--)
		shift
		break ;;
	esac
done

if [ $# -ne 1 ]
then
	usage
fi

patch_file=$1
[ -z "$opt_p" ] && opt_p=1

case "$patch_file" in
*.bz2)
	command="bzip2 -cd $patch_file";;
*.gz)
	command="gzip -cd $patch_file";;
*)
	command="cat $patch_file";;
esac

# Neither `+++' nor `---' works for all patches; patch looks at the
# file system to determine which file name to use.

eval $command \
|  awk '/^\+\+\+[ \t]/ {
	sub(/^\+\+\+[ \t]/, "")
	sub(/[ \t].*/, "")
	sub(/^\/dev\/null/, "")
	for (i=0; i<'$opt_p'; i++)
		sub(/^[^\/]*\//, "")
	print
	}' \
| sort \
| uniq