added getiface.sh

README

@@ -15,4 +15,4 @@ policyd-550.sh			Grep the mail.log for e-mails rejected by policyd-weight and sc
 rblcheck.sh			Check if your server is listed on an DNSBL
 tls_stats.sh			If you own a mailserver sending e-mails via TLS, show stats of peers
 www-perms.sh			Analyze your $documentroot for files writable by www user/group
-
+getiface.sh			Shows which interface would be used to connect to a specific host/IP

getiface.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+#
+# Shows which interface would be used
+# to connecto to an IP address/hostname
+
+INPUT=$1
+
+if [ -z $INPUT ]; then
+	echo "Need an IP/hostname"
+	exit
+fi
+
+if [ $(echo $INPUT | grep -c '[a-z]') -gt 0 ]; then
+	INPUT=$(dig +short $INPUT | tail -1)
+fi
+
+echo -n "Interface: "
+ip -o route get $INPUT | perl -nle 'if(/dev\s+(\S+)/) {print $1}'