Improved chroot detection, stolen from udev postinst.

1 files changed, 14 insertions, 2 deletions

diff --git a/policy-rc.d b/policy-rc.d
index bf0e993..8972383 100755
--- a/policy-rc.d
+++ b/policy-rc.d
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# $Id: policy-rc.d,v 1.3 2006-04-22 16:04:55 jonas Exp $
+# $Id: policy-rc.d,v 1.4 2007-01-03 14:38:03 jonas Exp $
 #
 # Copyright © 2006 Jonas Smedegaard <dr@jones.dk>
 # Description: Suppress system V scripts if invoked within a chroot.
@@ -26,6 +26,18 @@ TEMP=`getopt -s sh --long list,quiet -n "$PRG" -- "$@"`
 if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi
 eval set -- "$TEMP"
 
+# Stolen from udev postinst
+chrooted() {
+	if [ "$(stat -c %d/%i /)" = "$(stat -Lc %d/%i /proc/1/root 2>/dev/null)" ];
+	then
+		# the devicenumber/inode pair of / is the same as that of /sbin/init's
+		# root, so we're *not* in a chroot and hence return false.
+		return 1
+	fi
+	echo "A chroot environment has been detected, udev not started."
+	return 0
+}
+
 quiet=""
 list=""
 while true ; do
@@ -55,7 +67,7 @@ EOF
 	exit 0
 fi
 
-if [ ! -r /proc/1/root ]; then
+if ! chrooted; then
 	if ! [ "$quiet" ]; then
 		echo >&2 "Chroot environment detected, suppressing sysV script."
 	fi