Subject: bug#31709: 27.0.50; Wishlist: Perhaps Emacs should load a file when getting a particular signal?

From: Eli Zaretskii <[email-masked]>
Date: Mon, 04 Jun 2018 19:02:57 +0300

> From: Lars Ingebrigtsen <[email-masked]>
> Date: Mon, 04 Jun 2018 13:29:44 +0200
> 
> 
> It would be really nice if I could just ssh to the machine where the
> Emacs is running, do "kill -USR1 <pid>" and then ... Emacs could do
> something.  Like load "~/.emacs.d/load-file-USR1" or something.  Or just
> start emacs-server.  

The node "Misc Events" in the ELisp manual explains how you can bind
commands to 'sigusr1' and 'sigusr2' pseudo-function keys.  Isn't that
what you want?