[src/trunk]: src/sbin/devpubd/hooks safely update existing wedge links

[mlelstv <mlelstv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a4e0883b275d
branches:  trunk
changeset: 336440:a4e0883b275d
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sun Mar 01 14:21:17 2015 +0000

description:
safely update existing wedge links

diffstat:

 sbin/devpubd/hooks/02-wedgenames |  11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diffs (27 lines):

diff -r 4dd5d76535f6 -r a4e0883b275d sbin/devpubd/hooks/02-wedgenames
--- a/sbin/devpubd/hooks/02-wedgenames  Sun Mar 01 13:43:51 2015 +0000
+++ b/sbin/devpubd/hooks/02-wedgenames  Sun Mar 01 14:21:17 2015 +0000
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# $NetBSD: 02-wedgenames,v 1.2 2015/02/15 15:56:30 jmcneill Exp $
+# $NetBSD: 02-wedgenames,v 1.3 2015/03/01 14:21:17 mlelstv Exp $
 #
 # Try to maintain symlinks to wedge devices
 #
@@ -52,7 +52,14 @@
                test -d $wedgedir || mkdir -m 755 $wedgedir
                basedir=$(dirname "$wedgedir/$n")
                test -d "$basedir" || mkdir -p -m 755 "$basedir"
-               ln -s "/dev/$1" "$wedgedir/$n"
+               if oldlink=$(readlink "$wedgedir/$n"); then
+                       if [ x"$oldlink" != "/dev/$1" ]; then
+                               rm -f "$wedgedir/$n"
+                               ln -s "/dev/$1" "$wedgedir/$n"
+                       fi
+               else
+                       ln -s "/dev/$1" "$wedgedir/$n"
+               fi
                ;;
        esac
 }