Ask Different is a question and answer site for power users of Apple hardware and software. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

GNU Screen's default meta-key is Ctrl-a, which is really inconvenient for me because I frequently use Ctrl-a and Ctrl-e to move the cursor to the beginning or end of the line.

I'd prefer to change this to Cmd-a instead. I know this can be changed in my .screenrc file, but how do I encode the Cmd key?

share|improve this question
I assume you use Ctrl-a too often to get used to Ctrl-a (release ctrl) a to send Ctrl-a to the shell? - The problem with Cmnd-a is that it is the builtin for "Select All Text", which I am not sure how you will be able to undo. – Jason Salaz Apr 19 '11 at 23:12
@VxJasonxV hmm, I may be able to live with Ctrl-a,a but yeah I will probably mess it up too often. If Cmd-a won't work I'd settle for something like Shift-Cmd-a. – Adam Lassek Apr 19 '11 at 23:22
Also see… – Stefan Lasiewski Apr 26 '12 at 20:18
up vote 4 down vote accepted

I generally think the command idea is a bad one, because it is intended to be the system key for app manipulation. Cmd-l appears to be unbound in the application menus, but I couldn't use any tricks to view what it's keycode may be. Thus, I would suggest Shift-Ctrl-a.

Having said that, if I understand the man page, and a resource on the Ubuntu Forums on the topic, I believe you can change it to Shift-Ctrl-a either by using the -e flag (which I suggest you use to test with before putting it in your ~/.screenrc).

You should be able to run screen -e ^AA. ^ is a common identifier for "Ctrl", and A means capital-a (shift + a), as opposed to a lowercase a, meaning the character by itself.

If that works, you should be able to add a line into your ~/.screenrc that says: escape ^AA for it to automatically take place on any standard execution of screen just by itself.

share|improve this answer

As usual, I would also recommend trying out tmux. It's kind of a "screen on steroids". It uses C-b as its prefix key, but even that is configurable. tmux allows you to easily configure every aspect of it. As per the tmux FAQ, you can change the prefix to C-a like this:

set -g prefix C-a
unbind C-b
bind C-a send-prefix

Of course, since you wanted to get rid of C-a anyway, you may be happy with C-b instead.

You can easily install tmux if you have MacPorts installed, by running:

sudo port install tmux
share|improve this answer
Thanks, for the record I have long since switched to tmux. – Adam Lassek May 31 '13 at 18:57

run 'cat' in a terminal and press cmd-a to see what characters it sends. You can then use that in your .screenrc

share|improve this answer
Welcome to the site! How does this differ from the other answer? If it does, can you please elaborate your answer a bit to make it easier to understand and follow? – patrix May 31 '13 at 10:53

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.