From 468576ecd0f5f8f66fc9578f6b0d404534078815 Mon Sep 17 00:00:00 2001
From: root <root@schaltschrank-pi>
Date: Thu, 23 Feb 2017 11:49:57 +0000
Subject: [PATCH] switched to implementation with pipe due to possible race
 conditions

---
 command_watcher.sh | 17 ++++++-----------
 shell.sh           |  6 ++++--
 2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/command_watcher.sh b/command_watcher.sh
index 4baa8fb..77debaa 100755
--- a/command_watcher.sh
+++ b/command_watcher.sh
@@ -1,7 +1,6 @@
 #!/bin/bash
 
 COMMAND_FILE=/tmp/command
-COMMAND_FILE_TMP=/tmp/command_tmp
 
 lounge_light() {
 	echo "not implemented"
@@ -12,13 +11,12 @@ lounge_light_toggle() {
 }
 
 cd "$(dirname $0)"
-touch "$COMMAND_FILE"
-chmod -f 666 "$COMMAND_FILE"
-while inotifywait -qq -e close_write "$COMMAND_FILE"; do
-	mv "$COMMAND_FILE" "$COMMAND_FILE_TMP"
-	sleep .1				# wait for possible further/parallel writes to end
+rm -f $COMMAND_FILE
+mkfifo $COMMAND_FILE
+chmod 666 $COMMAND_FILE
+while true; do
 	while IFS='' read -r line || [[ -n "$line" ]]; do
-		echo "Text read from file: $line"
+		echo "command received: $line"
 		case "$line" in
 			lounge_light_toggle)
 				lounge_light_toggle
@@ -31,8 +29,5 @@ while inotifywait -qq -e close_write "$COMMAND_FILE"; do
 				echo "lounge_light lounge_light_toggle" >&2
 				;;
 		esac
-	done < "$COMMAND_FILE_TMP"
-	rm "$COMMAND_FILE_TMP"
-	touch "$COMMAND_FILE"
-	chmod -f 666 "$COMMAND_FILE"
+	done < "$COMMAND_FILE"
 done
diff --git a/shell.sh b/shell.sh
index 05c8055..c507301 100755
--- a/shell.sh
+++ b/shell.sh
@@ -6,8 +6,10 @@
 #    command="/home/automation/chch-power/shell.sh",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa AAAA...
 
 COMMAND_FILE=/tmp/command
-touch $COMMAND_FILE
-chmod -f 666 $COMMAND_FILE
+if [ ! -p $COMMAND_FILE ]; then
+	echo "ERROR; command watcher not listening:" >&2
+	exit 1
+fi
 
 status() {
 	STATUS="$(cat /tmp/status)"