Re: How to make emacs display the warning messages which appear on tty1

* BP25 <[email protected]> :
Wrote on Mon, 30 Mar 2026 10:12:10 +0000:

> One thing at a time: how about channeling all such messages (the ones
> in tty12) into the *Messages* buffer. And  after, the ones in tty1
> (urgent messages) into the echo area.

This is how I'd do it if I had to clobber something up quickly

You ask your syslog daemon to send the syslog messages to some pipe
traditionally I prefer /dev/xconsole.

my /etc/rsyslog.d/15-xconsole.conf (in the sysklogd syntax) to send
all messages to /dev/xconsole in addition to tty8

*.* |/dev/xconsole
*.* |/dev/tty8

ls -l /dev/xconsole
prw-rw-rw- 1 root root 0 Apr  7 21:49 /dev/xconsole

you may have to use opentmpfiles to create it:

mknod -m 0666 /dev/xconsole p
chown root:tty /dev/xconsole

Then if rsyslog is sending messages to /dev/xconsole you can read it
on stdout with
socat PIPE:/dev/xconsole -

I'd run socat as a subprocess of emacs (instead of reading it directly)

;;  -*- lexical-binding: t -*-

(defvar-local xconsole-process-output nil "Partial output")

(defvar xconsole-buffer-name "*xconsole*")

(defun xconsole-process-filter (proc string) ;adapted from elisp.info
  (when (buffer-live-p (process-buffer proc))
    (with-current-buffer (process-buffer proc)
      (let ((moving (= (point) (process-mark proc))))
	(save-excursion
	  ;; Insert the text, advancing the process marker.
	  (goto-char (process-mark proc))
	  (insert string)
	  (set-marker (process-mark proc) (point)))
	(if moving (goto-char (process-mark proc))))
      (setq xconsole-process-output
	    (concat xconsole-process-output string))
      (when (= ?\n (aref xconsole-process-output
			 (1- (length xconsole-process-output))))
	(let ((lines (split-string xconsole-process-output "[\n\r]" t)))
	  (setq xoncole-process-output nil)
	  (dolist (line lines)
	    (message "On Xconsole: %s" line)))))))

(defun xconsole-process-sentiel(proc string)
  (with-current-buffer (process-buffer proc)
    (goto-char (process-mark proc))
    (insert "\nXconsole process ended at " (current-time-string) "\n\n")
    (message "Xconsole exited")))

(defun open-xconsole ()
  (interactive)
  (let* ((xconsole-buffer (get-buffer-create xconsole-buffer-name))
	 (proc (get-buffer-process xconsole-buffer)))
    (pop-to-buffer xconsole-buffer)
    (cond ((and proc (memq (process-status process) '(open run))) t)
	  (t ;; (syslog-mode)
	   (or (setq proc (start-process "xconsole" "*xconsole*"
					 "socat" "PIPE:/dev/xconsole" "-"))
	       (error "xconsole: couldn't open xconsole"))
	   (set-process-sentinel proc #'xconsole-process-sentiel)
	   (set-process-filter proc #'xconsole-process-filter)
	   (insert "XConsole Started at " (current-time-string) "\n")))))


M-x open-xconsole will run the socat process, all syslog output goes to
the "*xconsole*" buffer, in addition, each line is echoed in the message
area with (message).  This may get too chatty..