setxkbmap -option
Where can be for example of:
caps:none – Disables Caps Lock.
caps:super – Caps Lock becomes an additional Super (aka Win key).
caps:ctrl_modifier – Caps Lock becomes an additional Ctrl.
caps:numlock – Caps Lock becomes an additional Num Lock.
caps:escape – Caps Lock becomes an additional Escape.
caps:backspace – Caps Lock becomes an additional Backspace.
caps:swapescape – Caps Lock becomes Escape, and Escape becomes Caps Lock
Note: Xmodmap is deprecated in favor of setxkbmap.