post-command-hook vs after-change-functions (was: how to restrict the numbers of chars in a buffer/file)

Uwe> Thanks did not know about that one. Lets see whether I can Uwe> manage. sjt> For your use case, David's suggestion is far better than mine (I sjt> focused on the "file" in "buffer/file"). Something very simple like sjt> (defvar uwe-message-limit 155) sjt> (lambda (&rest ignored) ; you may need to have correct sjt> ; dummy arguments here sjt> (when (> (buffer-size) uwe-message-limit) sjt> (warn "The message buffer has %d characters. sjt> You should reduce it to %d characters or less." sjt> (buffer-size) uwe-message-limit))) Thanks for that. Right your suggestion only worked (as the name of the hook indicated), when saving a file, while David's suggestion should work when changes in buffer a performed. However somehow that hook did not work for me, so I circumvent that difficulty by using the post-command-hook. This reminds me that the old refill.el from Bob Glickstein also used the after-change-functions hook and that made his code (at that time some 10 years ago) quite slow. On the other hand Per Abrahamsen's maniac.el uses post-command-hook and that code runs smoothly. Per even stated that he should use the after-change-functions but he did not get it to work. Another point, as the function is now, only a warning is released when more that 155 chars a typed. Is there any possibility that (X)Emacs would just refuse any more char. (I thought of using the error Funktion but even then I can continue typing.) Thanks Uwe