#!/bin/sh
#
# /usr/local/sbin/aptdpkgro
# Put together and tweaked by Jonas Smedegaard <dr@jones.dk>
# 2001-2006
#
# $Id: aptdpkgro,v 1.2 2006-07-16 12:33:59 jonas Exp $
#
# Auto re-mounting of a readonly /usr
# Put the following in a file below /etc/apt/apt.conf.d:
#
# // Auto re-mounting of a readonly /usr
# // Based on mail from Anthony Towns <aj@azure.humbug.org.au>
# // http://lists.debian.org/debian-devel/2001/debian-devel-200111/msg00212.html
# 
# // This is the intended thing:
# // DPkg {
# // 	Pre-Invoke {"mount -o remount,rw /usr";};
# // 	Post-Invoke {"mount -o remount,ro /usr";};
# // };
# 
# DPkg {
# 	Pre-Install-Pkgs {"/usr/local/sbin/aptdpkgro";};
# 	Pre-Invoke {"mount -o remount,rw /usr";};
# 	Post-Invoke {"/usr/local/sbin/aptdpkgclean; mount -o remount,ro /usr";};
# };
#

pathmatch="^/usr"

while read debname; do
	pkg=$(dpkg --info $debname | sed -n 's/^ Package: *//p' | head -n 1)
	(dpkg -L "$pkg" 2>/dev/null || true) | grep "$pathmatch" |
	  while read file; do
		[ -f "$file" -a ! -L "$file" ] || continue
		dir=`dirname "$file"`;
		base=`basename "$file"`;
		inode=`find "$file" -printf "%i\n"`
		[ -L "$dir/.${base}.dpkg-ro-used.$inode" ] || continue
		(cd "$dir" && ln "$base" ".${base}.dpkg-ro-used.$inode")
		echo "$dir/.${base}.dpkg-ro-used.$inode"
	  done >>/var/lib/my_ro_hack.todel
done