#!/bin/sh
# $NetBSD: pkgvi,v 1.11 2011/08/23 21:47:18 abs Exp $
#
# Copyright (c) 2001 Tomasz Luchowski. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#	This product includes software developed by Tomasz Luchowski for
#	the NetBSD Project
# 4. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

if [ "$PKGEDITOR" != "" ]; then
	editor="$PKGEDITOR"
elif [ "$EDITOR" != "" ]; then
	editor="$EDITOR"
else
	editor="vi"
fi

progname=`basename $0`

if [ $# -eq 0 ]
then
	echo Usage: $progname file >&2
	exit 1
fi

file="$1"
cmd=""
case x"$file" in
        x+*) cmd="$1"; shift ; file="$1" ;;
esac

if [ ! -f "$file" ]
then
	echo "$progname: $file: No such file"
	exit 2
fi

if [ -f "$file.orig" ]
then
	chmod u+w "$file"
	$editor $cmd "$file"
	echo "$progname: Backup already exists. For a diff type:"
        echo "pkgdiff $file"
	exit 0
fi

bfile=`basename "$file"`
dfile=`dirname "$file"`

ext=`echo $bfile | awk -F. '{ print $NF }'`

if [ "$bfile" != "$ext" ]; then
	tmp="$dfile/$bfile.$$.$ext"
else
	tmp="$file.$$"
fi

cp "$file" "$tmp"
chmod u+w "$tmp"

if [ $? -ne 0 ]; then
	echo "$progname: unable to create temporary file"
	exit 1
fi

$editor $cmd "$tmp"

if cmp "$file" "$tmp" >/dev/null 2>&1
then
	echo "$progname: File unchanged."
else
	mv "$file" "$file.orig"
	mv "$tmp" "$file"
	echo "$progname: File was modified. For a diff, type:"
	echo "pkgdiff \"$file\""
fi

if [ -f "$tmp" ]
then
	rm "$tmp"
fi

if [ -f "$tmp~" ]
then
	rm "$tmp~"
fi