SSH Screen Ignoring CTRL

Question

When I SSH into a particular server and launch screen, it ignores my CTRL+a key combo. Instead of CTRL+a c creating a new screen window, it instead acts as if I had just typed c. Other key combos fail in a similar way.

I've tried launching screen using screen -e ^jj to bind to j instead of a, but I still get the same result as above.

I tried adding a .screenrc file to my homedir that I know works on other machines, but it has no impact.

I also tried launch a zsh shell instead of bash.

Any ideas where to start to try and fix this? This basically renders screen unusable.

Thanks

Answer 1

screen reads commands from several configuration files during startup, as described in the FILES section of the man page or the Customizing Screen section of the User's Manual (also available, if it's installed, by typing info screen).

The files read are:

• The file named by the $SYSSCREENRC environment variable (this may or may not be enabled)
• /etc/screenrc
• The file named by the $SCREENRC environment variable`
• $HOME/.screenrc

(These interact and are searched in various ways that I don't entirely understand.)

In your particular case, based on the comments, the system on which you're running screen happens to have a /etc/screenrc file that contains an escape command that overrides the default.

A digression: in my own $HOME/.screenrc I have:

escape ^@^@

This sets the escape character to the null character, which can be entered by typing Ctrl-space. I find it easier to type, and less likely to conflict with other uses, than the default Ctrl-A. The only conflict I run into is the Emac set-mark-command function, and for that it's easy enough to type it twice.