Do not call alert subprocesses synchronously #116
Description
This can cause Emacs to lock up if Emacs is being used as the notification daemon (ie EDNC). I use this advice to get around this:
(defun cae-notifications-call-process-advice (orig-fun program &optional infile destination display &rest args)
"Advice function to make `call-process` run asynchronously using `start-process`."
;; Generate a unique process name
(let* ((process-name (generate-new-buffer-name (concat "async-" (file-name-nondirectory program))))
;; Determine the buffer based on DESTINATION
(buffer (cond
((eq destination t) (current-buffer))
((bufferp destination) destination)
((stringp destination) (get-buffer-create destination))
((and (listp destination)
(eq (car destination) :file))
;; For DESTINATION of the form (:file FILE), create a temporary buffer
(generate-new-buffer (concat "*" process-name "*")))
(t nil))) ;; For nil or 0, output is discarded
;; Use a pipe for the process communication
(process-connection-type nil)
;; Start the process asynchronously
(proc (apply 'start-process process-name buffer program args)))
;; If INFILE is specified, send its contents to the process
(when infile
(with-temp-buffer
(insert-file-contents infile)
(process-send-region proc (point-min) (point-max)))
(process-send-eof proc)) ;; Signal that we've finished sending input
;; Handle DESTINATION being (:file FILE)
(when (and (listp destination)
(eq (car destination) :file))
(let ((file (cadr destination)))
;; Set up a sentinel to write output to FILE when the process exits
(set-process-sentinel
proc
(lambda (proc event)
(when (eq (process-status proc) 'exit)
(with-current-buffer (process-buffer proc)
(write-region (point-min) (point-max) file nil 'quiet))
(kill-buffer (process-buffer proc)))))))
;; If DISPLAY is non-nil and a buffer is associated, display the buffer
(when (and display buffer)
(display-buffer buffer))
;; Since the process is asynchronous, we return nil
nil))
;;;###autoload
(defun cae-notifications-wrap-async-call-process-a (oldfun &rest args)
(advice-add #'call-process :around #'cae-ednc-call-process-advice)
(unwind-protect (apply oldfun args)
(advice-remove #'call-process #'cae-ednc-call-process-advice)))