I'm using tmux 2.0 on CentOS 6.7(without X).
How can I use
Caps Lock instead of
Ctrl in tmux?
Unfortunately, you cannot do it at the tmux layer. The tmux man page
has a section titled
KEY BINDINGS which lists the special keys that can be
mapped within tmux. Caps lock is not one of them:
In addition, the following special key names are accepted: Up, Down, Left, Right, BSpace, BTab, DC (Delete), End, Enter, Escape, F1 to F12, Home, IC (Insert), NPage/PageDown/PgDn, PPage/PageUp/PgUp, Space, and Tab.
Fortunately, you should be able to do it easily at the CentOS layer.
There are a few ways of doing it, I prefer the following:
setxkbmap -layout us -option ctrl:nocaps
xmodmap -e 'clear Lock'
xmodmap -e 'keycode 0x7e = Control_R'
xmodmap -e 'add Control = Control_R'
Which you can put into your
.bashrc file, or wherever commands are run on startup of your system.
There may also be a way to change the keyboard layout in a configuration program within CentOS. I'm not very familiar with it, but Caps Lock to Control is a pretty common request and you should be able to find it if you search for doing it in CentOS, Linux, or anything other than tmux.