jenkins shell monitor: suppress noise when showing offline nodes

Signed-off-by: Holger Levsen <holger@layer-acht.org>

bin/jenkins-shell-monitor.sh

@@ -106,7 +106,12 @@ main_loop() {
 		echo "=== jenkins/trbo shell monitor ==="
 		echo
 		echo "relevant lines from ~jenkins/offline_nodes:"
-		grep -A 2342 Also ~jenkins/offline_nodes | sed '/^$/d'
+		grep -A 2342 Also ~jenkins/offline_nodes | tac | sed -e '/# none atm/,+1d' | tac | sed '/^$/d'
+		# ^^^ this line explained:
+		# we grep for everything after the string 'Also" because we know the document and this will never change... m( :)
+		# tac is reverse cat. so doing it twice allows us to use sed backwards
+		# the first sed removes the matching line and the following (which due to tac is the previous one)
+		# the second sed command removes empty lines
 		echo
 		for j in $SEQ2 ; do
 			echo -n "#"