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 ;; * XXX 1.0.9 Ken Manheimer:
61 ;; - Allow existing shell buffers names as completions, even though they
62 ;; duplicate the names with paths. The different behavior for entries
63 ;; with existing buffers is actually useful. And in accord with actual
64 ;; behavior, where changing path for existing shells doesn't, actually.
65 ;; - Add paths to buffers started without one, if multishell history dir
66 ;; tracking is enabled.
67 ;; - Substantial code cleanup:
68 ;; - simplify multishell-start-shell-in-buffer, in particular using
69 ;; shell function, rather than unnecessarily going underneath it.
70 ;; - fallback to eval-after-load in emacs, that lack
71 ;; with-eval-after-load (eg, emacs 23).
72 ;; - save-match-data, where match-string is used
73 ;; - resituate some helpers
74 ;; * 2016-01-24 1.0.8 Ken Manheimer:
75 ;; - Work around the shell/tramp mishandling of remote+sudo+homedir problem!
76 ;; The work around is clean and simple, basically using high-level `cd'
77 ;; API and not messing with the low-level default-directory setting.
78 ;; (Turns out the problem was not in my local config. Good riddance to the
79 ;; awkward failure handler!)
80 ;; - Clean up code resolving the destination shell, starting to document the
81 ;; decision tree in the process. See getting-to-a-shell.md in the
82 ;; multishell repository, https://github.com/kenmanheimer/EmacsMultishell
83 ;; - There may be some shake-out on resolving the destination shell, but
84 ;; this release gets the fundamental functionality soundly in place.
85 ;; * 2016-01-23 1.0.7 Ken Manheimer:
86 ;; - Remove notes about tramp remote+sudo+homedir problem. Apparently it's
87 ;; due to something in my local site configuration (happens with -q but
89 ;; * 2016-01-22 1.0.6 Ken Manheimer:
90 ;; - Add multishell-version function.
91 ;; - Tweak commentary/comments/docstrings.
92 ;; - Null old multishell-buffer-name-history var, if present.
93 ;; * 2016-01-16 1.0.5 Ken Manheimer:
94 ;; - History now includes paths, when designated.
95 ;; - Actively track current directory in history entries that have a path.
96 ;; Custom control: multishell-history-entry-tracks-current-directory
97 ;; - Offer to remove shell's history entry when buffer is killed.
98 ;; (Currently the only UI mechanism to remove history entries.)
99 ;; - Fix - prevent duplicate entries for same name but different paths
100 ;; - Fix - recognize and respect tramp path syntax to start in home dir
101 ;; - Simplify history var name, migrate existing history if any from old name
102 ;; * 2016-01-04 1.0.4 Ken Manheimer - Released to ELPA
103 ;; * 2016-01-02 Ken Manheimer - working on this in public, but not yet released.
105 ;; TODO and Known Issues:
107 ;; * Find suitable, internally consistent ways to tidy completions, eg:
108 ;; - first list completions for active shells, then present but inactive,
110 ;; - some way for user to toggle between presenting just buffer names vs
112 ;; - without cutting user off from easy editing of path
113 ;; - maybe use keybindings that wrap minibuffer completion keys
114 ;; - minibuffer-local-completion-map, minibuffer-local-must-match-map
115 ;; - setup minibuffer with these vars just before doing completions
116 ;; - minibuffer exit reverts these vars, if necessary
117 ;; - toggles between name and name/path if repeat count provided
118 ;; - and an instruction about toggling in the completion buffer
119 ;; - eventually? "multishell-list-all", based on tabulated-list-mode
120 ;; - list-environment package is small, tidy, may be an easy template?
121 ;; - sort based on existing vs just historical
123 ;; - rename, change path, and remove history entries
124 ;; - could we use it as the transient completions help window?
125 ;; * Investigate whether we can recognize and provide for failed hops.
126 ;; - Tramp doesn't provide useful reactions for any hop but the first
127 ;; - Might be stuff we can do to detect and convey failures?
128 ;; - Might be no recourse but to seek tramp changes.
129 ;; * Add custom shell launch prep actions
130 ;; - shell commands to execute when shell name or path matches a regexp
131 ;; - list of [regexp, which (name, path, or both), command]
132 ;; - for, eg, knock commands or interface activations, whatever
133 ;; * Try minibuffer field boundary at beginning of tramp path, to see whether
134 ;; the field boundary magically enables tramp path completion.
135 ;; * Assess whether deletion of history entry via kill-buffer is sufficient.
143 (defvar multishell-version "1.0.8")
144 (defun multishell-version (&optional here)
145 "Return string describing the loaded multishell version."
147 (let ((msg (concat "Multishell " multishell-version)))
148 (if here (insert msg)
149 (if (called-interactively-p 'interactive)
153 (defgroup multishell nil
154 "Allout extension that highlights outline structure graphically.
156 Customize `allout-widgets-auto-activation' to activate allout-widgets
160 (defcustom multishell-command-key "\M- "
161 "The key to use if `multishell-activate-command-key' is true.
163 You can instead manually bind `multishell-pop-to-shell` using emacs
164 lisp, eg: (global-set-key \"\\M- \" 'multishell-pop-to-shell)."
168 (defvar multishell--responsible-for-command-key nil
169 "Coordination for multishell key assignment.")
170 (defun multishell-activate-command-key-setter (symbol setting)
171 "Implement `multishell-activate-command-key' choice."
172 (set-default 'multishell-activate-command-key setting)
173 (when (or setting multishell--responsible-for-command-key)
174 (multishell-implement-command-key-choice (not setting))))
175 (defun multishell-implement-command-key-choice (&optional unbind)
176 "If settings dicate, implement binding of multishell command key.
178 If optional UNBIND is true, globally unbind the key.
180 * `multishell-activate-command-key' - Set this to get the binding or not.
181 * `multishell-command-key' - The key to use for the binding, if appropriate."
183 (when (and (boundp 'multishell-command-key) multishell-command-key)
184 (global-unset-key multishell-command-key)))
185 ((not (and (boundp 'multishell-activate-command-key)
186 (boundp 'multishell-command-key)))
188 ((and multishell-activate-command-key multishell-command-key)
189 (setq multishell--responsible-for-command-key t)
190 (global-set-key multishell-command-key 'multishell-pop-to-shell))))
192 (defcustom multishell-activate-command-key nil
193 "Set this to impose the `multishell-command-key' binding.
195 You can instead manually bind `multishell-pop-to-shell` using emacs
196 lisp, eg: (global-set-key \"\\M- \" 'multishell-pop-to-shell)."
198 :set 'multishell-activate-command-key-setter
201 ;; Implement the key customization whenever the package is loaded:
202 (if (fboundp 'with-eval-after-load)
203 (with-eval-after-load "multishell"
204 (multishell-implement-command-key-choice))
205 (eval-after-load "multishell"
206 (multishell-implement-command-key-choice)))
208 (defcustom multishell-pop-to-frame nil
209 "*If non-nil, jump to a frame already showing the shell, if another one is.
211 Otherwise, disregard already-open windows on the shell if they're
212 in another frame, and open a new window on the shell in the
215 \(Use `pop-up-windows' to change multishell other-window vs
216 current-window behavior.)"
220 (defcustom multishell-history-entry-tracks-current-directory t
221 "Maintain shell's current directory in its multishell history entry.
223 When set, the history entry for shells started with explicit
224 paths will track the shell's current working directory. (Explicit
225 paths will not be added to local shells started without one,
228 If `savehist-save-minibuffer-history' is enabled, the current
229 working directory of shells \(that were started with an explicit
230 path) will be conveyed between emacs sessions."
234 (defvar multishell-history nil
235 "Name/path entries, most recent first.")
236 ;; Migrate the few pre 1.0.5 users to changed history var:
237 (when (and (not multishell-history)
238 (boundp 'multishell-buffer-name-history)
239 multishell-buffer-name-history)
240 (setq multishell-history multishell-buffer-name-history
241 multishell-buffer-name-history nil))
243 (defvar multishell-primary-name "*shell*"
244 "Default shell name for un-modified multishell-pop-to-shell buffer target.
246 This is set by `multishell-pop-to-shell' as the current default,
247 when invoked with doubled universal argument.
249 If you want the designated primary that you have at the end of
250 one emacs session to be resumed at the next, customize
251 `savehist-additional-variables' to include the
252 `multishell-primary-name'.")
254 ;; Multiple entries happen because completion also adds name to history.
255 (defun multishell-register-name-to-path (name path)
256 "Add or replace entry associating NAME with PATH in `multishell-history'.
258 If NAME already had a PATH and new PATH is empty, retain the prior one.
260 Promote added/changed entry to the front of the list."
261 ;; Add or promote to the front, tracking path changes in the process.
262 (let* ((entries (multishell-history-entries name))
264 (dolist (entry entries)
265 (when (string= path "")
266 ;; Retain explicit established path.
267 (setq path (cadr (multishell-split-entry entry))))
268 (setq multishell-history (delete entry multishell-history)))
269 (setq multishell-history (push (concat name path)
270 multishell-history))))
272 (defun multishell-history-entries (name)
273 "Return `multishell-history' entry that starts with NAME, or nil if none."
275 (let ((match-expr (concat "^" name "\\\(/.*$\\\)?$"))
277 (dolist (entry multishell-history)
278 (when (and (string-match match-expr entry)
279 (not (member entry got)))
280 (setq got (cons entry got))))
283 (defun multishell-pop-to-shell (&optional arg)
284 "Easily navigate to and within multiple shell buffers, local and remote.
286 Use universal arguments to launch and choose between alternate
287 shell buffers and to select which is default. Append a path to
288 a new shell name to launch a shell in that directory, and use
289 Emacs tramp syntax to launch a remote shell.
291 Customize-group `multishell' to set up a key binding and tweak behaviors.
293 ==== Basic operation:
295 - If the current buffer is shell-mode (or shell-mode derived)
296 buffer then focus is moved to the process input point.
298 \(You can use a universal argument go to a different shell
299 buffer when already in a buffer that has a process - see
302 - If not in a shell buffer (or with universal argument), go to a
303 window that is already showing the (a) shell buffer, if any.
305 In this case, the cursor is left in its prior position in the
306 shell buffer. Repeating the command will then go to the
307 process input point, per the first item in this list.
309 We respect `pop-up-windows', so you can adjust it to set the
310 other-buffer/same-buffer behavior.
312 - Otherwise, start a new shell buffer, using the current
313 directory as the working directory.
315 If a buffer with the resulting name exists and its shell process
316 was disconnected or otherwise stopped, it's resumed.
318 ===== Universal arg to start and select between named shell buffers:
320 You can name alternate shell buffers to create or return to using
321 single or doubled universal arguments:
323 - With a single universal argument, prompt for the buffer name
324 to use (without the asterisks that shell mode will put around
325 the name), defaulting to 'shell'.
327 Completion is available.
329 This combination makes it easy to start and switch across
330 multiple shell restarts.
332 - A double universal argument will prompt for the name *and* set
333 the default to that name, so the target shell becomes the
336 See `multishell-primary-name' for info about preserving the
337 setting across emacs restarts.
339 ===== Select starting directory and remote host:
341 The shell buffer name you give to the prompt for a universal arg
342 can include an appended path. That will be used for the startup
343 directory. You can use tramp remote syntax to specify a remote
344 shell. If there is an element after a final '/', that's used for
345 the buffer name. Otherwise, the host, domain, or path is used.
349 * '#root/sudo:root@localhost:/etc' for a buffer named \"*#root*\" with a
350 root shell starting in /etc.
352 * '/ssh:example.net:' for a shell buffer in your homedir on example.net.
353 The buffer will be named \"*example.net*\".
355 * '#ex/ssh:example.net|sudo:root@example.net:/var/log' for a root shell
356 starting in /var/log on example.net named \"*#ex*\".
358 * 'interior/ssh:gateway.corp.com|ssh:interior.corp.com:' to go
359 via gateway.corp.com to your homedir on interior.corp.com. The
360 buffer will be named \"*interior*\". You could append a sudo
361 hop to the path, combining the previous example, and so on.
363 File visits from the shell, and many common emacs activities like
364 dired, will be on the host where the shell is running, in the
365 auspices of the target account, and relative to the current
368 You can change the startup path for a shell buffer by editing it
369 at the completion prompt. The new path will not take effect for
370 an already-running shell.
372 To remove a shell buffer's history entry, kill the buffer and
373 affirm removal of the entry when prompted.
375 ===== Activate savehist to retain shell buffer names and paths across Emacs restarts:
377 To have emacs maintain your history of shell buffer names and paths,
378 customize the savehist group to activate savehist."
382 (let* ((from-buffer (current-buffer))
383 (from-buffer-is-shell (derived-mode-p 'shell-mode))
384 (primary-name-unbracketed (multishell-unbracket-asterisks
385 multishell-primary-name))
386 (fallthrough-name (if from-buffer-is-shell
387 (buffer-name from-buffer)
388 primary-name-unbracketed))
389 (doublearg (equal arg '(16)))
390 (target-name-and-path
391 (multishell-resolve-target-name-and-path
393 (or (multishell-read-bare-shell-buffer-name
394 (format "Shell buffer name [%s]%s "
395 primary-name-unbracketed
396 (if doublearg " <==" ":"))
397 primary-name-unbracketed)
398 primary-name-unbracketed)
400 (use-path (cadr target-name-and-path))
401 (target-shell-buffer-name (car target-name-and-path))
402 (target-buffer (get-buffer target-shell-buffer-name))
403 (curr-buff-proc (get-buffer-process from-buffer))
407 ;; Register early so the entry is pushed to the front:
408 (multishell-register-name-to-path (multishell-unbracket-asterisks
409 target-shell-buffer-name)
413 (setq multishell-primary-name target-shell-buffer-name))
419 ((and (or curr-buff-proc from-buffer-is-shell)
421 (eq from-buffer target-buffer)
422 (not (eq target-shell-buffer-name (buffer-name from-buffer))))
423 ;; In a shell buffer, but not named - stay in buffer, but go to end.
424 (setq already-there t))
426 ((string= (buffer-name) target-shell-buffer-name)
427 ;; Already in the specified shell buffer:
428 (setq already-there t))
430 ((or (not target-buffer)
432 (multishell-get-visible-window-for-buffer target-buffer))))
433 ;; No preexisting shell buffer, or not in a visible window:
434 (when (not (get-buffer target-shell-buffer-name))
435 (message "Creating new shell buffer '%s'" target-shell-buffer-name))
436 (pop-to-buffer target-shell-buffer-name pop-up-windows))
438 ;; Buffer exists and already has a window - jump to it:
439 (t (if (and multishell-pop-to-frame
441 (not (equal (window-frame (selected-window))
442 (window-frame inwin))))
443 (select-frame-set-input-focus (window-frame inwin)))
444 (if (not (string= (buffer-name (current-buffer))
445 target-shell-buffer-name))
446 (pop-to-buffer target-shell-buffer-name t))))
448 ;; We're in the buffer. Activate:
450 (if (not (comint-check-proc (current-buffer)))
451 (multishell-start-shell-in-buffer (buffer-name (current-buffer))
454 ;; If the destination buffer has a stopped process, resume it:
455 (let ((process (get-buffer-process (current-buffer))))
456 (if (and process (equal 'stop (process-status process)))
457 (continue-process process)))
459 (when (or already-there
460 (equal (current-buffer) from-buffer))
461 (goto-char (point-max))
462 (and (get-buffer-process from-buffer)
463 (goto-char (process-mark (get-buffer-process from-buffer)))))))
465 (defun multishell-kill-buffer-query-function ()
466 "Offer to remove multishell-history entry for buffer."
467 ;; Removal choice is crucial, so users can, eg, kill a shell with huge
468 ;; output backlog, while keeping the history entry to easily restart it.
470 ;; We use kill-buffer-query-functions instead of kill-buffer-hook because:
472 ;; 1. It enables the user to remove the history without actually killing a
473 ;; running buffer, by not confirming the subsequent running-proc query.
474 ;; 2. kill-buffer-hooks often fails to run when killing shell buffers!
475 ;; It's probably due to failures in other hooks - beyond our control -
476 ;; and anyway, I like the first reason well enough.
478 ;; (Use condition-case to avoid inadvertant disruption of kill-buffer
479 ;; activity. kill-buffer happens behind the scenes a whole lot.)
481 (dolist (entry (and (derived-mode-p 'shell-mode)
482 (multishell-history-entries
483 (multishell-unbracket-asterisks (buffer-name)))))
485 (y-or-n-p (format "Remove multishell history entry `%s'? "
487 (setq multishell-history
488 (delete entry multishell-history))))
490 (message "multishell-kill-buffer-query-function error: %s" err)))
492 (add-hook 'kill-buffer-query-functions 'multishell-kill-buffer-query-function)
494 (defun multishell-get-visible-window-for-buffer (buffer)
495 "Return visible window containing buffer."
498 (function (lambda (win)
499 (if (and (eq (window-buffer win) buffer)
500 (equal (frame-parameter
501 (selected-frame) 'display)
503 (window-frame win) 'display)))
504 (throw 'got-a-vis win))))
508 (defun multishell-read-bare-shell-buffer-name (prompt default)
509 "PROMPT for shell buffer name, sans asterisks. Indicate DEFAULT in prompt.
511 Return the supplied name, if provided, else return nil."
514 ;; Plain shell buffer names appended with names from name/path hist:
516 (mapcar (lambda (buffer)
517 (let* ((name (multishell-unbracket-asterisks
518 (buffer-name buffer))))
519 (and (buffer-live-p buffer)
520 (with-current-buffer buffer
521 ;; Shell mode buffers.
522 (and (derived-mode-p 'shell-mode)
523 (comint-check-proc (current-buffer))))
527 (got (completing-read prompt
537 'multishell-history)))
538 (if (not (string= got ""))
542 (defun multishell-resolve-target-name-and-path (path-ish)
543 "Given name/tramp-path PATH-ISH, resolve buffer name and initial directory.
545 The name is the part of the string up to the first '/' slash, if
546 any. Missing pieces are filled in from remote path elements, if
547 any, and multishell history. Given a path and no name, either the
548 host-name, domain-name, final directory name, or local host name
551 Return them as a list (name path), with name asterisk-bracketed
552 and path nil if none resolved."
553 (let* ((splat (multishell-split-entry (or path-ish "")))
559 (if (file-remote-p path)
560 (let ((vec (tramp-dissect-file-name path)))
561 (or (tramp-file-name-host vec)
562 (tramp-file-name-domain vec)
563 (tramp-file-name-localname vec)
565 multishell-primary-name)))
566 ;; No path - get one from history, if present.
568 (setq name multishell-primary-name))
569 (mapcar #'(lambda (entry)
570 (when (or (not path) (string= path ""))
571 (setq path (cadr (multishell-split-entry entry)))))
572 (multishell-history-entries
573 (multishell-unbracket-asterisks name))))
574 (list (multishell-bracket-asterisks name) path)))
576 (defun multishell-start-shell-in-buffer (buffer-name path)
577 "Start, restart, or continue a shell in BUFFER-NAME on PATH."
578 (let* ((buffer (get-buffer buffer-name))
582 (setq is-active (comint-check-proc buffer))
584 (when (and path (not is-active))
586 (when (and (derived-mode-p 'shell-mode) (file-remote-p path))
587 ;; Returning to disconnected remote shell - do some tidying:
588 (tramp-cleanup-connection
589 (tramp-dissect-file-name default-directory 'noexpand)
590 'keep-debug 'keep-password))
592 (message "Connecting to %s" path)
597 (defun multishell-track-dirchange (name newpath)
598 "Change multishell history entry to track current directory."
599 (let* ((entries (multishell-history-entries name)))
600 (dolist (entry entries)
601 (let* ((name-path (multishell-split-entry entry))
602 (name (car name-path))
603 (path (or (cadr name-path) "")))
605 (let* ((is-remote (file-remote-p path))
606 (vec (and is-remote (tramp-dissect-file-name path nil)))
607 (localname (if is-remote
608 (tramp-file-name-localname vec)
611 (replace-regexp-in-string (if (string= localname "")
613 (regexp-quote localname))
623 (newpath (if is-remote
624 (tramp-make-tramp-file-name (aref vec 0)
630 (newentry (concat name newpath))
631 (membership (member entry multishell-history)))
633 (setcar membership newentry))))))))
634 (defvar multishell-was-default-directory ()
635 "Provide for tracking directory changes.")
636 (make-variable-buffer-local 'multishell-was-default-directory)
637 (defun multishell-post-command-business ()
638 "Do multishell bookkeeping."
639 ;; Update multishell-history with dir changes.
641 (when (and multishell-history-entry-tracks-current-directory
642 (derived-mode-p 'shell-mode))
643 (let ((curdir (if (file-remote-p default-directory)
644 (tramp-file-name-localname
645 (tramp-dissect-file-name default-directory))
647 (when (not (string= curdir (or multishell-was-default-directory "")))
648 (multishell-track-dirchange (multishell-unbracket-asterisks
651 (setq multishell-was-default-directory curdir)))
652 ;; To avoid disruption as a pervasive hook function, swallow all errors:
654 (message "multishell-post-command-business error: %s" err))))
655 (add-hook 'post-command-hook 'multishell-post-command-business)
657 (defun multishell-split-entry (entry)
658 "Given multishell name/path ENTRY, return the separated name and path pair.
660 Returns nil for empty parts, rather than the empty string."
662 (string-match "^\\([^/]*\\)\\(/?.*\\)?" entry)
663 (let ((name (match-string 1 entry))
664 (path (match-string 2 entry)))
665 (and (string= name "") (setq name nil))
666 (and (string= path "") (setq path nil))
668 (defun multishell-bracket-asterisks (name)
669 "Return a copy of name, ensuring it has an asterisk at the beginning and end."
670 (if (not (string= (substring name 0 1) "*"))
671 (setq name (concat "*" name)))
672 (if (not (string= (substring name -1) "*"))
673 (setq name (concat name "*")))
675 (defun multishell-unbracket-asterisks (name)
676 "Return a copy of name, removing asterisks, if any, at beginning and end."
677 (if (string= (substring name 0 1) "*")
678 (setq name (substring name 1)))
679 (if (string= (substring name -1) "*")
680 (setq name (substring name 0 -1)))
683 (provide 'multishell)
685 ;;; multishell.el ends here