I'm trying to enter a tab character in Firefox/Chrome text boxes without having to copy-paste from Emacs. The combination Ctrl+Shift+U then 0009 does not work. In fact, it does not seem to work for most "control" characters. However, it works for pretty much any printable character including non-ASCII. This is really bizarre. Google doesn't seem to reveal any such inconsistent behavior. Anyone know why this combination bans whitespace? I can repeat this behavior in any program including Leafpad and LibreOffice.
U+2023: ‣
U+0100: Ā
U+0009: (nothing)
U+000A: (nothing)
U+0020: (space)
1 Answer
Got it. The reason it was working as root and not my regular user was because the environment variables GTK_IM_MODULE and QT_IM_MODULE were being forced to xim for all regular users, regardless of runs of im-config. The only module I have installed under Lubuntu is ibus, so I'm not surprised by this strange behavior. A few articles on the net brought those variables to my attention so I started debugging around them. When I noticed they were being set to xim persistently, I decided to force them to ibus under /etc/environment. You have the less aggressive option of setting them in .bashrc or some equivalent. Regardless, this will restore full Ctrl+Shift+U functionality.
