1 ;;; multishell.el --- facilitate multiple local and remote shell buffers
3 ;; Copyright (C) 1999-2016 Free Software Foundation, Inc. and Ken Manheimer
5 ;; Author: Ken Manheimer <ken.manheimer@gmail.com>
7 ;; Created: 1999 -- first public availability
9 ;; URL: https://github.com/kenmanheimer/EmacsMultishell
13 ;; Easily use and navigate multiple shell buffers, including remote shells.
14 ;; Fundamentally, multishell is the function `multishell-pop-to-shell' -
15 ;; a la `pop-to-buffer' - plus a keybinding. Together, they enable you to:
17 ;; * Get to the input point from wherever you are in a shell buffer,
18 ;; ... or to any of your shell buffers, from anywhere inside emacs.
20 ;; * Use universal arguments to launch and choose among alternate shell buffers,
21 ;; ... and change which is the current default.
23 ;; * Easily restart disconnected shells, or shells from prior sessions
24 ;; ... the latter from Emacs builtin savehist minibuf history persistence
26 ;; * Append a path to a new shell name to launch a shell in that directory,
27 ;; ... and use a path with Emacs tramp syntax to launch a remote shell -
30 ;; * `#root/sudo:root@localhost:/etc` for a buffer named "*#root*" with a
31 ;; root shell starting in /etc.
33 ;; * `/ssh:example.net:` for a shell buffer in your homedir on example.net.
34 ;; The buffer will be named "*example.net*".
36 ;; * `#ex/ssh:example.net|sudo:root@example.net:/var/log` for a root shell
37 ;; starting in /var/log on example.net named "*#ex*".
39 ;; * 'interior/ssh:gateway.corp.com|ssh:interior.corp.com:' to go via
40 ;; gateway.corp.com to your homedir on interior.corp.com. The buffer
41 ;; will be named "*interior*". You could append a sudo hop, and so on.
43 ;; * Thanks to tramp, file visits from the shell will seamlessly be in
44 ;; the auspices of the target account, and relative to the current
45 ;; directory, on the host where the shell is running.
47 ;; See the `multishell-pop-to-shell` docstring for details.
49 ;; Customize-group `multishell' to select and activate a keybinding and set
50 ;; various behaviors. Customize-group `savehist' to preserve buffer
51 ;; names/paths across emacs restarts.
54 ;; [the multishell repository](https://github.com/kenmanheimer/EmacsMultishell)
55 ;; issue tracker to report problems, suggestions, etc, and see that
56 ;; repository for a bit more documentation.
60 ;; * 2016-01-24 1.0.8 Ken Manheimer:
61 ;; - Work around the shell/tramp mishandling of remote+sudo+homedir problem!
62 ;; The work around is clean and simple, basically using high-level `cd'
63 ;; API and not messing with the low-level default-directory setting.
64 ;; (Turns out the problem was not in my local config. Good riddance to the
65 ;; awkward failure handler!)
66 ;; - Clean up code resolving the destination shell, starting to document the
67 ;; decision tree in the process. See getting-to-a-shell.md in the
68 ;; multishell repository, https://github.com/kenmanheimer/EmacsMultishell
69 ;; - There may be some shake-out on resolving the destination shell, but
70 ;; this release gets the fundamental functionality soundly in place.
71 ;; * 2016-01-23 1.0.7 Ken Manheimer:
72 ;; - Remove notes about tramp remote+sudo+homedir problem. Apparently it's
73 ;; due to something in my local site configuration (happens with -q but
75 ;; * 2016-01-22 1.0.6 Ken Manheimer:
76 ;; - Add multishell-version function.
77 ;; - Tweak commentary/comments/docstrings.
78 ;; - Null old multishell-buffer-name-history var, if present.
79 ;; * 2016-01-16 1.0.5 Ken Manheimer:
80 ;; - History now includes paths, when designated.
81 ;; - Actively track current directory in history entries that have a path.
82 ;; Custom control: multishell-history-entry-tracks-current-directory
83 ;; - Offer to remove shell's history entry when buffer is killed.
84 ;; (Currently the only UI mechanism to remove history entries.)
85 ;; - Fix - prevent duplicate entries for same name but different paths
86 ;; - Fix - recognize and respect tramp path syntax to start in home dir
87 ;; - Simplify history var name, migrate existing history if any from old name
88 ;; * 2016-01-04 1.0.4 Ken Manheimer - Released to ELPA
89 ;; * 2016-01-02 Ken Manheimer - working on this in public, but not yet released.
93 ;; * Find suitable, internally consistent ways to tidy completions, eg:
94 ;; - first list completions for active shells, then present but inactive,
96 ;; - some way for user to toggle between presenting just buffer names vs
98 ;; - without cutting user off from easy editing of path
99 ;; - maybe use keybindings that wrap minibuffer completion keys
100 ;; - minibuffer-local-completion-map, minibuffer-local-must-match-map
101 ;; - setup minibuffer with these vars just before doing completions
102 ;; - minibuffer exit reverts these vars, if necessary
103 ;; - toggles between name and name/path if last command was one of them
104 ;; - and an instruction in the completion buffer
105 ;; - "complete again immediately to toggle name vs name/path completions"
106 ;; * Add custom shell launch prep actions
107 ;; - shell commands to execute when shell name or path matches a regexp
108 ;; - list of [regexp, which (name, path, or both), command]
109 ;; - for, eg, knock commands or interface activations, whatever
110 ;; * Try minibuffer field boundary at beginning of tramp path, to see whether
111 ;; the field boundary magically enables tramp path completion.
112 ;; * Assess whether deletion of history entry via kill-buffer is sufficient.
120 (defvar multishell-version "1.0.8")
121 (defun multishell-version (&optional here)
122 "Return string describing the loaded multishell version."
124 (let ((msg (concat "Multishell " multishell-version)))
125 (if here (insert msg)
126 (if (called-interactively-p 'interactive)
130 (defgroup multishell nil
131 "Allout extension that highlights outline structure graphically.
133 Customize `allout-widgets-auto-activation' to activate allout-widgets
137 (defcustom multishell-command-key "\M- "
138 "The key to use if `multishell-activate-command-key' is true.
140 You can instead manually bind `multishell-pop-to-shell` using emacs
141 lisp, eg: (global-set-key \"\\M- \" 'multishell-pop-to-shell)."
145 (defvar multishell--responsible-for-command-key nil
146 "Coordination for multishell key assignment.")
147 (defun multishell-activate-command-key-setter (symbol setting)
148 "Implement `multishell-activate-command-key' choice."
149 (set-default 'multishell-activate-command-key setting)
150 (when (or setting multishell--responsible-for-command-key)
151 (multishell-implement-command-key-choice (not setting))))
152 (defun multishell-implement-command-key-choice (&optional unbind)
153 "If settings dicate, implement binding of multishell command key.
155 If optional UNBIND is true, globally unbind the key.
157 * `multishell-activate-command-key' - Set this to get the binding or not.
158 * `multishell-command-key' - The key to use for the binding, if appropriate."
160 (when (and (boundp 'multishell-command-key) multishell-command-key)
161 (global-unset-key multishell-command-key)))
162 ((not (and (boundp 'multishell-activate-command-key)
163 (boundp 'multishell-command-key)))
165 ((and multishell-activate-command-key multishell-command-key)
166 (setq multishell--responsible-for-command-key t)
167 (global-set-key multishell-command-key 'multishell-pop-to-shell))))
169 (defcustom multishell-activate-command-key nil
170 "Set this to impose the `multishell-command-key' binding.
172 You can instead manually bind `multishell-pop-to-shell` using emacs
173 lisp, eg: (global-set-key \"\\M- \" 'multishell-pop-to-shell)."
175 :set 'multishell-activate-command-key-setter
178 ;; Implement the key customization whenever the package is loaded:
179 (if (fboundp 'with-eval-after-load)
180 (with-eval-after-load "multishell"
181 (multishell-implement-command-key-choice))
182 (eval-after-load "multishell"
183 (multishell-implement-command-key-choice)))
185 (defcustom multishell-pop-to-frame nil
186 "*If non-nil, jump to a frame already showing the shell, if another one is.
188 Otherwise, disregard already-open windows on the shell if they're
189 in another frame, and open a new window on the shell in the
192 \(Use `pop-up-windows' to change multishell other-window vs
193 current-window behavior.)"
197 (defcustom multishell-history-entry-tracks-current-directory t
198 "Maintain shell's current directory in its multishell history entry.
200 When set, the history entry for shells started with explicit
201 paths will track the shell's current working directory. (Explicit
202 paths will not be added to local shells started without one,
205 If `savehist-save-minibuffer-history' is enabled, the current
206 working directory of shells \(that were started with an explicit
207 path) will be conveyed between emacs sessions."
211 (defvar multishell-history nil
212 "Name/path entries, most recent first.")
213 ;; Migrate the few pre 1.0.5 users to changed history var:
214 (when (and (not multishell-history)
215 (boundp 'multishell-buffer-name-history)
216 multishell-buffer-name-history)
217 (setq multishell-history multishell-buffer-name-history
218 multishell-buffer-name-history nil))
220 (defvar multishell-primary-name "*shell*"
221 "Default shell name for un-modified multishell-pop-to-shell buffer target.
223 This is adjusted by `multishell-pop-to-shell' when it is
224 invoked (with doubled universal argument) to set the default.
226 To track the current primary across emacs restarts, add the name
227 of this variable to `savehist-additional-variables' by
228 customizing the latter.")
230 ;;; Can't just add multishell-primary-name to savehist-additional-variables
231 ;;; - it'll be lost any time the user runs emacs without loading
232 ;;; multishell. So instead, inform the user that they can customize
233 ;;; savehist-additional-variables.
235 ;;; I suspect that including savehist-additional-variables *on*
236 ;;; savehist-additional-variables could avoid this problem, as long as it
237 ;;; doesn't conflict with user customizations. However, even if that works,
238 ;;; doing so from multishell would change a behavior (for the better, but)
239 ;;; beyond multishell's scope, making the change hard to track down.
241 ;; (when (not (member 'multishell-primary-name
242 ;; savehist-additional-variables))
243 ;; (setq savehist-additional-variables
244 ;; (cons 'multishell-primary-name savehist-additional-variables)))
246 ;; Multiple entries happen because completion also adds name to history.
247 (defun multishell-register-name-to-path (name path)
248 "Add or replace entry associating NAME with PATH in `multishell-history'.
250 If NAME already had a PATH and new PATH is empty, retain the prior one.
252 Promote added/changed entry to the front of the list."
253 ;; Add or promote to the front, tracking path changes in the process.
254 (let* ((entries (multishell-history-entries name))
256 (dolist (entry entries)
257 (when (string= path "")
258 ;; Retain explicit established path.
259 (setq path (cadr (multishell-split-entry entry))))
260 (setq multishell-history (delete entry multishell-history)))
261 (setq multishell-history (push (concat name path)
262 multishell-history))))
264 (defun multishell-history-entries (name)
265 "Return `multishell-history' entry that starts with NAME, or nil if none."
266 (let ((match-expr (concat "^" name "\\\(/.*$\\\)?$"))
268 (dolist (entry multishell-history)
269 (when (and (string-match match-expr entry)
270 (not (member entry got)))
271 (setq got (cons entry got))))
274 (defun multishell-pop-to-shell (&optional arg)
275 "Easily navigate to and within multiple shell buffers, local and remote.
277 Use universal arguments to launch and choose between alternate
278 shell buffers and to select which is default. Append a path to
279 a new shell name to launch a shell in that directory, and use
280 Emacs tramp syntax to launch a remote shell.
282 Customize-group `multishell' to set up a key binding and tweak behaviors.
284 ==== Basic operation:
286 - If the current buffer is shell-mode (or shell-mode derived)
287 buffer then focus is moved to the process input point.
289 \(You can use a universal argument go to a different shell
290 buffer when already in a buffer that has a process - see
293 - If not in a shell buffer (or with universal argument), go to a
294 window that is already showing the (a) shell buffer, if any.
296 In this case, the cursor is left in its prior position in the
297 shell buffer. Repeating the command will then go to the
298 process input point, per the first item in this list.
300 We respect `pop-up-windows', so you can adjust it to set the
301 other-buffer/same-buffer behavior.
303 - Otherwise, start a new shell buffer, using the current
304 directory as the working directory.
306 If a buffer with the resulting name exists and its shell process
307 was disconnected or otherwise stopped, it's resumed.
309 ===== Universal arg to start and select between named shell buffers:
311 You can name alternate shell buffers to create or return to using
312 single or doubled universal arguments:
314 - With a single universal argument, prompt for the buffer name
315 to use (without the asterisks that shell mode will put around
316 the name), defaulting to 'shell'.
318 Completion is available.
320 This combination makes it easy to start and switch across
321 multiple shell restarts.
323 - A double universal argument will prompt for the name *and* set
324 the default to that name, so the target shell becomes the
327 See `multishell-primary-name' for info about preserving the
328 setting across emacs restarts.
330 ===== Select starting directory and remote host:
332 The shell buffer name you give to the prompt for a universal arg
333 can include an appended path. That will be used for the startup
334 directory. You can use tramp remote syntax to specify a remote
335 shell. If there is an element after a final '/', that's used for
336 the buffer name. Otherwise, the host, domain, or path is used.
340 * '#root/sudo:root@localhost:/etc' for a buffer named \"*#root*\" with a
341 root shell starting in /etc.
343 * '/ssh:example.net:' for a shell buffer in your homedir on example.net.
344 The buffer will be named \"*example.net*\".
346 * '#ex/ssh:example.net|sudo:root@example.net:/var/log' for a root shell
347 starting in /var/log on example.net named \"*#ex*\".
349 * 'interior/ssh:gateway.corp.com|ssh:interior.corp.com:' to go
350 via gateway.corp.com to your homedir on interior.corp.com. The
351 buffer will be named \"*interior*\". You could append a sudo
352 hop to the path, combining the previous example, and so on.
354 Thanks to tramp, file visits from the shell, and many common
355 emacs activities, like dired, will seamlessly be in the auspices
356 of the target account, and relative to the current directory, on
357 the host where the shell is running.
359 You can change the startup path for a shell buffer by editing it
360 at the completion prompt. The new path will be preserved in
361 history but will not take effect for an already-running shell.
363 To remove a shell buffer's history entry, kill the buffer and
364 affirm removal of the entry when prompted.
366 ===== Activate savehist to retain shell buffer names and paths across Emacs restarts:
368 To have emacs maintain your history of shell buffer names and paths,
369 customize the savehist group to activate savehist."
373 (let* ((from-buffer (current-buffer))
374 (from-buffer-is-shell (derived-mode-p 'shell-mode))
375 (primary-name-unbracketed (multishell-unbracket-asterisks
376 multishell-primary-name))
377 (fallthrough-name (if from-buffer-is-shell
378 (buffer-name from-buffer)
379 primary-name-unbracketed))
380 (doublearg (equal arg '(16)))
381 (target-name-and-path
382 (multishell-resolve-target-name-and-path
384 (or (multishell-read-bare-shell-buffer-name
385 (format "Shell buffer name [%s]%s "
386 primary-name-unbracketed
387 (if doublearg " <==" ":"))
388 primary-name-unbracketed)
389 primary-name-unbracketed)
391 (use-path (cadr target-name-and-path))
392 (target-shell-buffer-name (car target-name-and-path))
393 (target-buffer (get-buffer target-shell-buffer-name))
394 (curr-buff-proc (get-buffer-process from-buffer))
398 ;; Register early so the entry is pushed to the front:
399 (multishell-register-name-to-path (multishell-unbracket-asterisks
400 target-shell-buffer-name)
404 (setq multishell-primary-name target-shell-buffer-name))
410 ((and (or curr-buff-proc from-buffer-is-shell)
412 (eq from-buffer target-buffer)
413 (not (eq target-shell-buffer-name (buffer-name from-buffer))))
414 ;; In a shell buffer, but not named - stay in buffer, but go to end.
415 (setq already-there t))
417 ((string= (buffer-name) target-shell-buffer-name)
418 ;; Already in the specified shell buffer:
419 (setq already-there t))
421 ((or (not target-buffer)
423 (multishell-get-visible-window-for-buffer target-buffer))))
424 ;; No preexisting shell buffer, or not in a visible window:
425 (pop-to-buffer target-shell-buffer-name pop-up-windows))
427 ;; Buffer exists and already has a window - jump to it:
428 (t (if (and multishell-pop-to-frame
430 (not (equal (window-frame (selected-window))
431 (window-frame inwin))))
432 (select-frame-set-input-focus (window-frame inwin)))
433 (if (not (string= (buffer-name (current-buffer))
434 target-shell-buffer-name))
435 (pop-to-buffer target-shell-buffer-name t))))
437 ;; We're in the buffer. Activate:
439 (if (not (comint-check-proc (current-buffer)))
440 (multishell-start-shell-in-buffer (buffer-name (current-buffer))
443 ;; If the destination buffer has a stopped process, resume it:
444 (let ((process (get-buffer-process (current-buffer))))
445 (if (and process (equal 'stop (process-status process)))
446 (continue-process process)))
448 (when (or already-there
449 (equal (current-buffer) from-buffer))
450 (goto-char (point-max))
451 (and (get-buffer-process from-buffer)
452 (goto-char (process-mark (get-buffer-process from-buffer)))))))
454 (defun multishell-kill-buffer-query-function ()
455 "Offer to remove multishell-history entry for buffer."
456 ;; Removal choice is crucial, so users can, eg, kill a shell with huge
457 ;; output backlog, while keeping the history entry to easily restart it.
459 ;; We use kill-buffer-query-functions instead of kill-buffer-hook because:
461 ;; 1. It enables the user to remove the history without actually killing a
462 ;; running buffer, by not confirming the subsequent running-proc query.
463 ;; 2. kill-buffer-hooks often fails to run when killing shell buffers!
464 ;; It's probably due to failures in other hooks - beyond our control -
465 ;; and anyway, I like the first reason well enough.
467 ;; (Use condition-case to avoid inadvertant disruption of kill-buffer
468 ;; activity. kill-buffer happens behind the scenes a whole lot.)
470 (dolist (entry (and (derived-mode-p 'shell-mode)
471 (multishell-history-entries
472 (multishell-unbracket-asterisks (buffer-name)))))
474 (y-or-n-p (format "Remove multishell history entry `%s'? "
476 (setq multishell-history
477 (delete entry multishell-history))))
479 (message "multishell-kill-buffer-query-function error: %s" err)))
481 (add-hook 'kill-buffer-query-functions 'multishell-kill-buffer-query-function)
483 (defun multishell-get-visible-window-for-buffer (buffer)
484 "Return visible window containing buffer."
487 (function (lambda (win)
488 (if (and (eq (window-buffer win) buffer)
489 (equal (frame-parameter
490 (selected-frame) 'display)
492 (window-frame win) 'display)))
493 (throw 'got-a-vis win))))
497 (defun multishell-read-bare-shell-buffer-name (prompt default)
498 "PROMPT for shell buffer name, sans asterisks. Indicate DEFAULT in prompt.
500 Return the supplied name, if provided, else return nil."
503 ;; Plain shell buffer names appended with names from name/path hist:
505 (mapcar (lambda (buffer)
506 (let* ((name (multishell-unbracket-asterisks
507 (buffer-name buffer))))
508 (and (buffer-live-p buffer)
509 (with-current-buffer buffer
510 ;; Shell mode buffers.
511 (derived-mode-p 'shell-mode))
512 (not (multishell-history-entries name))
516 (got (completing-read prompt
526 'multishell-history)))
527 (if (not (string= got ""))
531 (defun multishell-resolve-target-name-and-path (path-ish)
532 "Given name/tramp-path PATH-ISH, resolve buffer name and initial directory.
534 The name is the part of the string up to the first '/' slash, if
535 any. Missing pieces are filled in from remote path elements, if
536 any, and multishell history. Given a path and no name, either the
537 host-name, domain-name, final directory name, or local host name
540 Return them as a list (name path), with name asterisk-bracketed
541 and path nil if none resolved."
542 (let* ((splat (multishell-split-entry (or path-ish "")))
548 (if (file-remote-p path)
549 (let ((vec (tramp-dissect-file-name path)))
550 (or (tramp-file-name-host vec)
551 (tramp-file-name-domain vec)
552 (tramp-file-name-localname vec)
554 multishell-primary-name)))
555 ;; No path - get one from history, if present.
557 (setq name multishell-primary-name))
558 (mapcar #'(lambda (entry)
559 (when (or (not path) (string= path ""))
560 (setq path (cadr (multishell-split-entry entry)))))
561 (multishell-history-entries
562 (multishell-unbracket-asterisks name))))
563 (list (multishell-bracket-asterisks name) path)))
565 (defun multishell-bracket-asterisks (name)
566 "Return a copy of name, ensuring it has an asterisk at the beginning and end."
567 (if (not (string= (substring name 0 1) "*"))
568 (setq name (concat "*" name)))
569 (if (not (string= (substring name -1) "*"))
570 (setq name (concat name "*")))
572 (defun multishell-unbracket-asterisks (name)
573 "Return a copy of name, removing asterisks, if any, at beginning and end."
574 (if (string= (substring name 0 1) "*")
575 (setq name (substring name 1)))
576 (if (string= (substring name -1) "*")
577 (setq name (substring name 0 -1)))
580 (defun multishell-start-shell-in-buffer (buffer-name path)
581 "Start, restart, or continue a shell in BUFFER-NAME on PATH."
582 (let* ((buffer (get-buffer buffer-name))
587 (when (and path (file-remote-p path))
589 (when (and (derived-mode-p 'shell-mode)
590 (not (comint-check-proc (current-buffer))))
591 ;; Returning to disconnected remote shell. Do some tidying:
592 (tramp-cleanup-connection
593 (tramp-dissect-file-name default-directory 'noexpand)
594 'keep-debug 'keep-password))
596 (message "Connecting to %s" path)
601 (defun multishell-track-dirchange (name newpath)
602 "Change multishell history entry to track current directory."
603 (let* ((entries (multishell-history-entries name)))
604 (dolist (entry entries)
605 (let* ((name-path (multishell-split-entry entry))
606 (name (car name-path))
607 (path (cadr name-path)))
609 (let* ((is-remote (file-remote-p path))
610 (vec (and is-remote (tramp-dissect-file-name path nil)))
611 (localname (if is-remote
612 (tramp-file-name-localname vec)
615 (replace-regexp-in-string (if (string= localname "")
617 (regexp-quote localname))
627 (newpath (if is-remote
628 (tramp-make-tramp-file-name (aref vec 0)
634 (newentry (concat name newpath))
635 (membership (member entry multishell-history)))
637 (setcar membership newentry))))))))
638 (defvar multishell-was-default-directory ()
639 "Provide for tracking directory changes.")
640 (make-variable-buffer-local 'multishell-was-default-directory)
641 (defun multishell-post-command-business ()
642 "Do multishell bookkeeping."
643 ;; Update multishell-history with dir changes.
645 (when (and multishell-history-entry-tracks-current-directory
646 (derived-mode-p 'shell-mode))
647 (let ((curdir (if (file-remote-p default-directory)
648 (tramp-file-name-localname
649 (tramp-dissect-file-name default-directory))
651 (when (and multishell-was-default-directory
652 (not (string= curdir multishell-was-default-directory)))
653 (multishell-track-dirchange (multishell-unbracket-asterisks
656 (setq multishell-was-default-directory curdir)))
657 ;; To avoid disruption as a pervasive hook function, swallow all errors:
659 (message "multishell-post-command-business error: %s" err))))
660 (add-hook 'post-command-hook 'multishell-post-command-business)
662 (defun multishell-split-entry (entry)
663 "Given multishell name/path ENTRY, return the separated name and path pair.
665 Returns nil for empty parts, rather than the empty string."
666 (string-match "^\\([^/]*\\)\\(/?.*\\)?" entry)
667 (let ((name (match-string 1 entry))
668 (path (match-string 2 entry)))
669 (and (string= name "") (setq name nil))
670 (and (string= path "") (setq path nil))
673 (provide 'multishell)
675 ;;; multishell.el ends here