How to put ansi-term state in mode line?

Question

Is there a way to put the ansi-term state (char-mode or term-mode) in the mode line?

Answer 1

Do you mean term-char-mode and term-line-mode? These are printed by default in the mode-line here (Emacs 28.1 and 29.0.50). Here is how it looks when starting from emacs -q:

So then we can look up the mode-line-format where we find that the modes are formatted via the mode-line-modes variable. Finally from that variable we find that the ':char/:line' part is formatted via the mode-line-process variable.

Answer 2

Add 'mode-line-process to your mode-line format.