Cnc_cntrl_v1.ino opens in text edit

Ubuntu on a Macbook Air trying to connect to Arduino. Instruction say open cnc_cntrl_v1.ino but all I can get it to open in is text edit. Not what I experienced using Mac OS. Web control opens but shows not connected. I figured doing the firmware update would connect me, The usb shows a com port of /dev/tty/ACM0 in web control setting, Maslow settings, which seems odd. Any clue what I’m doing wrong?

is the port open in another process? in settings -> maslow settings, if you hit the refresh button, what ports show up?

The list is as long as your arm from s1 t0 s31 plus printk and the one that disappears when I unplug the usb to the Arduino.

I found the Arduino ide available in my Ubuntu release so upon opening it I was able to connect to the Arduino board. This permitted the WebControl to connect to the Arduino. It is connected through /dev/tty/acm0. Installing the Arduino ide required that I grant myself access to the USB in order to get the Arduino to talk to my laptop which was why I couldn’t connect through WebControl when I first fired it up. Bottom line problem solved.