Problem using Ctrl+Arrow keys in Vim when using Byobu with tmux
The problem is twofold. First, tmux by default converts the control-arrow keys from one type of escape sequence to another. So special keys such as controlleft are sent to vim without the modifier, e.g., left. If you use cat -v to see the different escape sequences, you might see something like this
^[OD
versus this (outside tmux):
^[[1;5D
The line
set-window-option -g xterm-keys on
fixes that aspect. The other part is that tmux by default uses the terminal description for screen. That terminal description does not describe the control-arrow keys. These entries from the terminal database would be the most appropriate for VTE (gnome-terminal):
- screen.vte
- screen.vte-256color
There are others, such as
- screen.xterm-new
- screen.xterm-256color
which would be automatically selected when running in screen if the corresponding TERM outside were vte, vte-256color, etc. tmux does not do this automatic-selection; you have to modify its configuration file.
By the way, there is no "screen.xterm" entry because it would interfere with some usages of screen. There is no conflict with TERM=xterm-new.
If you have a default (minimal) terminal database such as ncurses-base in Debian, you might not have those. More common would be xterm-256color, which is close enough to use with vim and tmux.
For example, if I add this to my .tmux.conf file, it behaves as you expect in vim:
set -g default-terminal "xterm-256color"
Further reading:
- XTERM Extensions (terminal database)
- vim: how to specify arrow keys
- How can I see what my keyboard sends?
From here you can unbind the key combination in byobu:
Create a file ~/.byobu/.tmux.conf with (or add if the file exists):
set-window-option -g xterm-keys on
Then add the following to ~/.byobu/keybindings.tmux:
unbind-key -n C-Left
unbind-key -n C-Right