Map Capslock to Escape on Linux
If you do VIM you may want to remap your escape key to capslock. I personally never use capslock but it is easier to reach than ESC.
X Keyboard Extension
If you use X11/Xorg you should have XKeyboard installed. This gives you access to the setxkbmap program.
setxkbmap
setxkbmap -option caps:escape
Note: setxkbmap only sets the current xorg session.
If you want it to set on starting xorg (startx) then you should put it in your startup scripts for xorg.
~/.xinitrc- Basic initial startup for xorg~/.Xmodmap- Mappings map for xorg. May not be loaded by default.
# Map capslock key to escape
setxkbmap -option caps:escape