Prevent multiple instances of sleep_weather.sh from running at once

scripts/sleep_weather.sh

@@ -4,8 +4,19 @@
 
 fahrenheit=$1
 
+LOCKFILE=/tmp/.dracula-tmux-weather.lock
+
+ensure_single_process()
+{
+	# check for another running instance of this script and terminate it if found
+	[ -f $LOCKFILE ] && ps -p "$(cat $LOCKFILE)" -o cmd= | grep -F " ${BASH_SOURCE[0]}" && kill "$(cat $LOCKFILE)"
+	echo $$ > $LOCKFILE
+}
+
 main()
 {
+	ensure_single_process
+
 	current_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 	$current_dir/weather.sh > $current_dir/../data/weather.txt
@@ -20,6 +31,8 @@ main()
 			break
 		fi
 	done
+
+	rm $LOCKFILE
 }
 
 #run main driver function