mjhjmtu

I have been trying to figure out this thing called XCompose. Apparently if I use it correctly, I can do things like writing é or any such letter easily but don't understand how it works:

I did do the first part in https://wiki.debian.org/XCompose

i.e.

$ cat .xsessionrc
xmodmap -e "keysym Super_L = Multi_key" 

but do not understand what <dead_tilde> <dead_grave> <dead_circumflex> mean.

Are these keys which I need to map similar to what mapping I had to do in .xsessionrc ?

The short answer is that if you map a compose key, you needn’t worry about dead keys.

<dead_tilde> etc. correspond to keys in the keymap which are “dead”, i.e. which don’t produce a character on their own but always combine with the next keystroke. For example, on French keyboards, there’s a ^ key to the right of P which allows you to produce “ê” etc., by pressing ^ e. These don’t need the compose key at all.

The compose key is used for mappings which start with <Multi_key> (look at /usr/share/X11/locale/en_US.UTF-8/Compose), and those use “normal” keys; for example, <Multi_key> <asciicircum> <e> means that you press your compose key, then ^ (the non-dead variant), then e, to get “ê”.

The standard accent compose sequences use the following keys for typical accents:

• 
  , for a cedilla;


• 
  ` for a grave accent;


• 
  ' for an acute accent;


• 
  ^ for a circumflex accent;


• 
  " for a diaeresis;


• 
  ~ for a tilde.

There are many, many more combinations, look at the Compose file mentioned above for details.