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136 lines
5.7 KiB
EmacsLisp
136 lines
5.7 KiB
EmacsLisp
;;; timer.el --- run a function with args at some time in future
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;; Copyright (C) 1990, 1993 Free Software Foundation, Inc.
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;; Maintainer: FSF
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs; see the file COPYING. If not, write to
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;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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;;; Commentary:
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;; This package gives you the capability to run Emacs Lisp commands at
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;; specified simes in the future, either as one-shots or periodically.
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;; The single entry point is `run-at-time'.
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;;; Code:
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(defvar timer-process nil)
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(defvar timer-alist ())
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(defvar timer-out "")
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(defvar timer-dont-exit nil
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;; this is useful for functions which will be doing their own erratic
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;; rescheduling or people who otherwise expect to use the process frequently
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"If non-nil, don't exit the timer process when no more events are pending.")
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;;;###autoload
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(defun run-at-time (time repeat function &rest args)
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"Run a function at a time, and optionally on a regular interval.
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Arguments are TIME, REPEAT, FUNCTION &rest ARGS.
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TIME, a string, can be specified absolutely or relative to now.
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TIME can also be an integer, a number of seconds.
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REPEAT, an integer number of seconds, is the interval on which to repeat
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the call to the function. If REPEAT is nil, call it just once.
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Absolute times may be specified in a wide variety of formats;
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Something of the form `HOUR:MIN:SEC TIMEZONE MONTH/DAY/YEAR', where
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all fields are numbers, works; the format used by the Unix `date'
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command works too.
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Relative times may be specified as a series of numbers followed by units:
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1 min denotes one minute from now.
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min does too.
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1 min 5 sec denotes 65 seconds from now.
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1 min 2 sec 3 hour 4 day 5 week 6 fortnight 7 month 8 year
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denotes the sum of all the given durations from now."
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(interactive "sRun at time: \nNRepeat interval: \naFunction: ")
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;; Make TIME a string.
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(if (integerp time)
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(setq time (format "%d sec" time)))
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(cond ((or (not timer-process)
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(memq (process-status timer-process) '(exit signal nil)))
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(if timer-process (delete-process timer-process))
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(setq timer-process (let ((process-connection-type nil))
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(start-process "timer" nil "timer"))
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timer-alist nil)
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(set-process-filter timer-process 'timer-process-filter)
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(set-process-sentinel timer-process 'timer-process-sentinel)
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(process-kill-without-query timer-process))
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((eq (process-status timer-process) 'stop)
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(continue-process timer-process)))
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;; There should be a living, breathing timer process now
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(let* ((token (concat (current-time-string) "-" (length timer-alist)))
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(elt (list token repeat function args)))
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(process-send-string timer-process (concat time "@" token "\n"))
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(setq timer-alist (cons elt timer-alist))
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elt))
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(defun cancel-timer (elt)
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"Cancel a timer previously made with `run-at-time'.
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The argument should be a value previously returned by `run-at-time'.
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Cancelling the timer means that nothing special
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will happen at the specified time."
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(setcar (cdr elt) nil)
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(setcar (cdr (cdr elt)) 'ignore))
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(defun timer-process-filter (proc str)
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(setq timer-out (concat timer-out str))
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(let (do token error)
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(while (string-match "\n" timer-out)
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(setq token (substring timer-out 0 (match-beginning 0))
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do (assoc token timer-alist)
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timer-out (substring timer-out (match-end 0)))
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(cond
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(do
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(apply (nth 2 do) (nth 3 do)) ; do it
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(if (natnump (nth 1 do)) ; reschedule it
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(send-string proc (concat (nth 1 do) " sec@" (car do) "\n"))
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(setq timer-alist (delq do timer-alist))))
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((string-match "timer: \\([^:]+\\): \\([^@]*\\)@\\(.*\\)$" token)
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(setq error (substring token (match-beginning 1) (match-end 1))
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do (substring token (match-beginning 2) (match-end 2))
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token (assoc (substring token (match-beginning 3) (match-end 3))
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timer-alist)
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timer-alist (delq token timer-alist))
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(ding 'no-terminate) ; using error function in process filters is rude
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(message "%s for %s; couldn't set at \"%s\"" error (nth 2 token) do))))
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(or timer-alist timer-dont-exit (process-send-eof proc))))
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(defun timer-process-sentinel (proc str)
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(let ((stat (process-status proc)))
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(if (eq stat 'stop) (continue-process proc)
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;; if it exited normally, presumably it was intentional.
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;; if there were no pending events, who cares that it exited?
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(if (or (not timer-alist) (eq stat 'exit)) ()
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(ding 'no-terminate)
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(message "Timer exited abnormally. All events cancelled."))
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;; Used to set timer-scratch to "", but nothing uses that var.
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(setq timer-process nil timer-alist nil))))
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(defun cancel-timer (function)
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"Cancel all events scheduled by `run-at-time' which would run FUNCTION."
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(interactive "aCancel function: ")
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(let ((alist timer-alist))
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(while alist
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(if (eq (nth 2 (car alist)) function)
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(setq timer-alist (delq (car alist) timer-alist)))
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(setq alist (cdr alist))))
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(or timer-alist timer-dont-exit (process-send-eof timer-process)))
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(provide 'timer)
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;;; timer.el ends here
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