Added error handling / cleanup

relaymyhome

@@ -31,10 +31,32 @@ wservice=`/usr/sbin/networksetup -listallnetworkservices | grep -Ei '(wi-fi|airp
 wifi=$(networksetup -listallhardwareports | awk "/$wservice/,/Ethernet/"' getline { print $2 }')
 
 WirelessMAC=$(networksetup -getmacaddress $wifi | awk '{print $3}')
+echo "Original MAC address is: $WirelessMAC"
+
+cleanup()
+{
+    sudo ifconfig $wifi lladdr $WirelessMAC
+    networksetup -setairportpower $wifi off
+    networksetup -setairportpower $wifi on
+
+    echo "Cycling of Relays has completed, MAC address reverted.\n"
+}
+
+ctrl_c()
+{
+  # user quit midway through, so we should revert
+  # the MAC address by calling our cleanup function
+  echo "*** Interrupted ***"
+  cleanup
+  exit $?
+}
+
+# trap keyboard interrupt (control-c) or unexpected quit
+trap ctrl_c SIGINT SIGTERM
 
 if  [ $1 == "full" ]
 then
-    # Generate a full list of 160 MAC's when "full" mode is specified
+    # Generate a full list of 160 MACs when "full" mode is specified
     # To use full mode: ./relaymyhome full
     # Check the repo at github for more information.
     echo "Full Mode enabled. Randomly seeding from full list of addresses."
@@ -46,7 +68,7 @@ then
     CharsA=("0" "1" "2" "3" "4" "5" "6" "7" "8" "9")
     CharsB=("0" "1" "2" "3" "4" "5" "6" "7" "8" "9" "A" "B" "C" "D" "E" "F")
 
-    # Create the addresses programatically
+    # Create the addresses programmatically
     count=0
     for i in "${CharsA[@]}"
     do
@@ -70,7 +92,7 @@ then
 
 
 else
-    # This standard set of MAC's will be used in standard mode
+    # This set of MACs will be used in standard mode
     # Usage: ./relaymyhome
     addr[0]='00:0D:67:15:2D:82'
     addr[1]='00:0D:67:15:D7:21'
@@ -105,10 +127,8 @@ else
     done
 fi
 
-sudo ifconfig $wifi lladdr $WirelessMAC
-networksetup -setairportpower $wifi off
-networksetup -setairportpower $wifi on
+# ... and we are done
 
+cleanup
 
-echo "Cycling of Relays has completed, MAC address reverted."
 echo "Time to check your StreetPasses!"