I'm using the Hacker's Keyboard, which provides extra keys such as control, alt, and so forth which are necessary when doing things like shell commands.
I'm having an issue where I can't undo in emacs using a single keystroke. Using ctrl-x,u works, but it very clumsy on a tablet, due to the fact that the there is no tactile feedback - so to undo accurately I have to type very slowly, which is the opposite of what I want to do when undoing, which is to quickly jump back several states. I could add something to my .emacs file to choose a different keystroke, but now I have several machines that I have to create or update an .emacs file on, so I would like to use the default if possible. And there is also the question of what key I would use: for instance, control-z is one possibility but that is already taken by suspend process. control-u is another, but it is already taken too.
The two default single keystrokes that emacs uses to undo are control-/ and control-_. However, when I try both of these keystrokes in Android, the control part seems to get lost. I have also tried
cat | hexdump or
cat directly from a shell prompt (ssh or terminal) and the control seems to get lost in those two, instead of seeing something like
^_ as expected. Other control characters work just fine, so I can't see how it's a general issue with either app not recognizing control characters.
From reading various pieces of documentation it seems like Android 3.0 Honeycomb added support for all the various control characters, although looking directly at the Android documentation I don't see a code for everything, so I'm not sure if this is something that just isn't supported or if the application is at fault, or if there is just something else that I have missed that is needed for this to work.