Update update option to checkout new branch

update

@@ -1,9 +1,20 @@
 #!/bin/bash
 
-echo -e "\nupdate script for CubeSatSim v2.0\n"
+echo -e "\nupdate script for CubeSatSim v2.1\n"
+
+FLAG=0
+checkout=0
+
+if [ -z "$1" ] ; then
+	checkout=0
+else
+	checkout=1
+	branch="$1"
+	echo $branch
+	FLAG=1
+fi
 
 if [ "$1" = "n" ] ; then
-# if [ -z "$2" ] ; then
 	noreboot=1
 else
 	noreboot=0
@@ -39,6 +50,10 @@ cd /home/pi/CubeSatSim
 
 git pull --no-rebase > .updated
 
+if [ $checkout -eq 1 ]; then
+	git checkout $branch
+fi
+
 make debug
 
 FILE=/home/pi/CubeSatSim/command_tx
@@ -57,8 +72,6 @@ else
     echo "0\n" > /home/pi/CubeSatSim/command_count.txt
 fi
 
-FLAG=0
-
 if [[ $(diff systemd/cubesatsim.service /etc/systemd/system/cubesatsim.service) ]]; then
   echo "changed cubesatsim.service."
   sudo cp /home/pi/CubeSatSim/systemd/cubesatsim.service /etc/systemd/system/cubesatsim.service
@@ -358,7 +371,7 @@ if [ "$noreboot" = "0" ] ; then
 	fi
 else
 	if [ $FLAG -eq 1 ]; then
-		echo "reboot needed for changes to take effect"
+		echo "reboot needed for changes to take effect" | wall
 	fi
 fi