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60370d40 | 1 | ;;; esh-io.el --- I/O management |
affbf647 | 2 | |
1a32899d | 3 | ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
114f9c96 | 4 | ;; 2008, 2009, 2010 Free Software Foundation, Inc. |
affbf647 | 5 | |
7de5b421 GM |
6 | ;; Author: John Wiegley <johnw@gnu.org> |
7 | ||
affbf647 GM |
8 | ;; This file is part of GNU Emacs. |
9 | ||
4ee57b2a | 10 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
affbf647 | 11 | ;; it under the terms of the GNU General Public License as published by |
4ee57b2a GM |
12 | ;; the Free Software Foundation, either version 3 of the License, or |
13 | ;; (at your option) any later version. | |
affbf647 GM |
14 | |
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
4ee57b2a | 21 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
affbf647 | 22 | |
affbf647 GM |
23 | ;;; Commentary: |
24 | ||
25 | ;; At the moment, only output redirection is supported in Eshell. To | |
26 | ;; use input redirection, the following syntax will work, assuming | |
27 | ;; that the command after the pipe is always an external command: | |
28 | ;; | |
29 | ;; cat <file> | <command> | |
30 | ;; | |
31 | ;; Otherwise, output redirection and piping are provided in a manner | |
32 | ;; consistent with most shells. Therefore, only unique features are | |
33 | ;; mentioned here. | |
34 | ;; | |
35 | ;;;_* Insertion | |
36 | ;; | |
37 | ;; To insert at the location of point in a buffer, use '>>>': | |
38 | ;; | |
39 | ;; echo alpha >>> #<buffer *scratch*>; | |
40 | ;; | |
41 | ;;;_* Pseudo-devices | |
42 | ;; | |
43 | ;; A few pseudo-devices are provided, since Emacs cannot write | |
44 | ;; directly to a UNIX device file: | |
45 | ;; | |
46 | ;; echo alpha > /dev/null ; the bit bucket | |
47 | ;; echo alpha > /dev/kill ; set the kill ring | |
48 | ;; echo alpha >> /dev/clip ; append to the clipboard | |
49 | ;; | |
50 | ;;;_* Multiple output targets | |
51 | ;; | |
52 | ;; Eshell can write to multiple output targets, including pipes. | |
53 | ;; Example: | |
54 | ;; | |
55 | ;; (+ 1 2) > a > b > c ; prints number to all three files | |
56 | ;; (+ 1 2) > a | wc ; prints to 'a', and pipes to 'wc' | |
57 | ||
8c7309fe GM |
58 | ;;; Code: |
59 | ||
5153ac72 GM |
60 | (provide 'esh-io) |
61 | ||
fc17acd1 GM |
62 | (eval-when-compile |
63 | (require 'cl) | |
64 | (require 'eshell)) | |
5153ac72 GM |
65 | |
66 | (defgroup eshell-io nil | |
67 | "Eshell's I/O management code provides a scheme for treating many | |
68 | different kinds of objects -- symbols, files, buffers, etc. -- as | |
69 | though they were files." | |
70 | :tag "I/O management" | |
71 | :group 'eshell) | |
72 | ||
affbf647 GM |
73 | ;;; User Variables: |
74 | ||
75 | (defcustom eshell-io-load-hook '(eshell-io-initialize) | |
76 | "*A hook that gets run when `eshell-io' is loaded." | |
77 | :type 'hook | |
78 | :group 'eshell-io) | |
79 | ||
80 | (defcustom eshell-number-of-handles 3 | |
81 | "*The number of file handles that eshell supports. | |
82 | Currently this is standard input, output and error. But even all of | |
83 | these Emacs does not currently support with asynchronous processes | |
84 | \(which is what eshell uses so that you can continue doing work in | |
85 | other buffers) ." | |
86 | :type 'integer | |
87 | :group 'eshell-io) | |
88 | ||
89 | (defcustom eshell-output-handle 1 | |
90 | "*The index of the standard output handle." | |
91 | :type 'integer | |
92 | :group 'eshell-io) | |
93 | ||
94 | (defcustom eshell-error-handle 2 | |
95 | "*The index of the standard error handle." | |
96 | :type 'integer | |
97 | :group 'eshell-io) | |
98 | ||
99 | (defcustom eshell-buffer-shorthand nil | |
100 | "*If non-nil, a symbol name can be used for a buffer in redirection. | |
101 | If nil, redirecting to a buffer requires buffer name syntax. If this | |
102 | variable is set, redirection directly to Lisp symbols will be | |
103 | impossible. | |
104 | ||
105 | Example: | |
106 | ||
107 | echo hello > '*scratch* ; works if `eshell-buffer-shorthand' is t | |
108 | echo hello > #<buffer *scratch*> ; always works" | |
109 | :type 'boolean | |
110 | :group 'eshell-io) | |
111 | ||
112 | (defcustom eshell-print-queue-size 5 | |
113 | "*The size of the print queue, for doing buffered printing. | |
114 | This is basically a speed enhancement, to avoid blocking the Lisp code | |
115 | from executing while Emacs is redisplaying." | |
116 | :type 'integer | |
117 | :group 'eshell-io) | |
118 | ||
119 | (defcustom eshell-virtual-targets | |
120 | '(("/dev/eshell" eshell-interactive-print nil) | |
121 | ("/dev/kill" (lambda (mode) | |
122 | (if (eq mode 'overwrite) | |
123 | (kill-new "")) | |
124 | 'eshell-kill-append) t) | |
125 | ("/dev/clip" (lambda (mode) | |
126 | (if (eq mode 'overwrite) | |
127 | (let ((x-select-enable-clipboard t)) | |
128 | (kill-new ""))) | |
129 | 'eshell-clipboard-append) t)) | |
130 | "*Map virtual devices name to Emacs Lisp functions. | |
131 | If the user specifies any of the filenames above as a redirection | |
132 | target, the function in the second element will be called. | |
133 | ||
134 | If the third element is non-nil, the redirection mode is passed as an | |
135 | argument (which is the symbol `overwrite', `append' or `insert'), and | |
136 | the function is expected to return another function -- which is the | |
137 | output function. Otherwise, the second element itself is the output | |
138 | function. | |
139 | ||
ca7aae91 JW |
140 | The output function is then called repeatedly with single strings, |
141 | which represents successive pieces of the output of the command, until nil | |
affbf647 GM |
142 | is passed, meaning EOF. |
143 | ||
144 | NOTE: /dev/null is handled specially as a virtual target, and should | |
145 | not be added to this variable." | |
146 | :type '(repeat | |
147 | (list (string :tag "Target") | |
148 | function | |
149 | (choice (const :tag "Func returns output-func" t) | |
150 | (const :tag "Func is output-func" nil)))) | |
151 | :group 'eshell-io) | |
152 | ||
153 | (put 'eshell-virtual-targets 'risky-local-variable t) | |
154 | ||
155 | ;;; Internal Variables: | |
156 | ||
157 | (defvar eshell-current-handles nil) | |
158 | ||
159 | (defvar eshell-last-command-status 0 | |
160 | "The exit code from the last command. 0 if successful.") | |
161 | ||
162 | (defvar eshell-last-command-result nil | |
163 | "The result of the last command. Not related to success.") | |
164 | ||
165 | (defvar eshell-output-file-buffer nil | |
166 | "If non-nil, the current buffer is a file output buffer.") | |
167 | ||
168 | (defvar eshell-print-count) | |
169 | (defvar eshell-current-redirections) | |
170 | ||
171 | ;;; Functions: | |
172 | ||
173 | (defun eshell-io-initialize () | |
174 | "Initialize the I/O subsystem code." | |
affbf647 GM |
175 | (add-hook 'eshell-parse-argument-hook |
176 | 'eshell-parse-redirection nil t) | |
177 | (make-local-variable 'eshell-current-redirections) | |
affbf647 GM |
178 | (add-hook 'eshell-pre-rewrite-command-hook |
179 | 'eshell-strip-redirections nil t) | |
affbf647 GM |
180 | (add-hook 'eshell-post-rewrite-command-hook |
181 | 'eshell-apply-redirections nil t)) | |
182 | ||
183 | (defun eshell-parse-redirection () | |
184 | "Parse an output redirection, such as '2>'." | |
185 | (if (and (not eshell-current-quoted) | |
186 | (looking-at "\\([0-9]\\)?\\(<\\|>+\\)&?\\([0-9]\\)?\\s-*")) | |
187 | (if eshell-current-argument | |
188 | (eshell-finish-arg) | |
189 | (let ((sh (match-string 1)) | |
190 | (oper (match-string 2)) | |
191 | ; (th (match-string 3)) | |
192 | ) | |
193 | (if (string= oper "<") | |
194 | (error "Eshell does not support input redirection")) | |
195 | (eshell-finish-arg | |
196 | (prog1 | |
197 | (list 'eshell-set-output-handle | |
6b0e3e4d | 198 | (or (and sh (string-to-number sh)) 1) |
affbf647 GM |
199 | (list 'quote |
200 | (aref [overwrite append insert] | |
201 | (1- (length oper))))) | |
202 | (goto-char (match-end 0)))))))) | |
203 | ||
204 | (defun eshell-strip-redirections (terms) | |
205 | "Rewrite any output redirections in TERMS." | |
206 | (setq eshell-current-redirections (list t)) | |
207 | (let ((tl terms) | |
208 | (tt (cdr terms))) | |
209 | (while tt | |
210 | (if (not (and (consp (car tt)) | |
211 | (eq (caar tt) 'eshell-set-output-handle))) | |
212 | (setq tt (cdr tt) | |
213 | tl (cdr tl)) | |
214 | (unless (cdr tt) | |
215 | (error "Missing redirection target")) | |
216 | (nconc eshell-current-redirections | |
217 | (list (list 'ignore | |
218 | (append (car tt) (list (cadr tt)))))) | |
219 | (setcdr tl (cddr tt)) | |
220 | (setq tt (cddr tt)))) | |
221 | (setq eshell-current-redirections | |
222 | (cdr eshell-current-redirections)))) | |
223 | ||
224 | (defun eshell-apply-redirections (cmdsym) | |
225 | "Apply any redirection which were specified for COMMAND." | |
226 | (if eshell-current-redirections | |
227 | (set cmdsym | |
228 | (append (list 'progn) | |
229 | eshell-current-redirections | |
230 | (list (symbol-value cmdsym)))))) | |
231 | ||
232 | (defun eshell-create-handles | |
233 | (standard-output output-mode &optional standard-error error-mode) | |
234 | "Create a new set of file handles for a command. | |
235 | The default location for standard output and standard error will go to | |
ca7aae91 JW |
236 | STANDARD-OUTPUT and STANDARD-ERROR, respectively. |
237 | OUTPUT-MODE and ERROR-MODE are either `overwrite', `append' or `insert'; | |
238 | a nil value of mode defaults to `insert'." | |
affbf647 GM |
239 | (let ((handles (make-vector eshell-number-of-handles nil)) |
240 | (output-target (eshell-get-target standard-output output-mode)) | |
241 | (error-target (eshell-get-target standard-error error-mode))) | |
242 | (aset handles eshell-output-handle (cons output-target 1)) | |
243 | (if standard-error | |
244 | (aset handles eshell-error-handle (cons error-target 1)) | |
245 | (aset handles eshell-error-handle (cons output-target 1))) | |
246 | handles)) | |
247 | ||
248 | (defun eshell-protect-handles (handles) | |
249 | "Protect the handles in HANDLES from a being closed." | |
250 | (let ((idx 0)) | |
251 | (while (< idx eshell-number-of-handles) | |
252 | (if (aref handles idx) | |
253 | (setcdr (aref handles idx) | |
254 | (1+ (cdr (aref handles idx))))) | |
255 | (setq idx (1+ idx)))) | |
256 | handles) | |
257 | ||
258 | (defun eshell-close-target (target status) | |
259 | "Close an output TARGET, passing STATUS as the result. | |
260 | STATUS should be non-nil on successful termination of the output." | |
261 | (cond | |
262 | ((symbolp target) nil) | |
263 | ||
264 | ;; If we were redirecting to a file, save the file and close the | |
265 | ;; buffer. | |
266 | ((markerp target) | |
267 | (let ((buf (marker-buffer target))) | |
268 | (when buf ; somebody's already killed it! | |
269 | (save-current-buffer | |
270 | (set-buffer buf) | |
271 | (when eshell-output-file-buffer | |
272 | (save-buffer) | |
273 | (when (eq eshell-output-file-buffer t) | |
274 | (or status (set-buffer-modified-p nil)) | |
275 | (kill-buffer buf))))))) | |
276 | ||
277 | ;; If we're redirecting to a process (via a pipe, or process | |
278 | ;; redirection), send it EOF so that it knows we're finished. | |
ca7aae91 | 279 | ((eshell-processp target) |
affbf647 GM |
280 | (if (eq (process-status target) 'run) |
281 | (process-send-eof target))) | |
282 | ||
283 | ;; A plain function redirection needs no additional arguments | |
284 | ;; passed. | |
285 | ((functionp target) | |
286 | (funcall target status)) | |
287 | ||
288 | ;; But a more complicated function redirection (which can only | |
289 | ;; happen with aliases at the moment) has arguments that need to be | |
290 | ;; passed along with it. | |
291 | ((consp target) | |
292 | (apply (car target) status (cdr target))))) | |
293 | ||
294 | (defun eshell-close-handles (exit-code &optional result handles) | |
295 | "Close all of the current handles, taking refcounts into account. | |
296 | EXIT-CODE is the process exit code; mainly, it is zero, if the command | |
297 | completed successfully. RESULT is the quoted value of the last | |
298 | command. If nil, then the meta variables for keeping track of the | |
299 | last execution result should not be changed." | |
300 | (let ((idx 0)) | |
301 | (assert (or (not result) (eq (car result) 'quote))) | |
302 | (setq eshell-last-command-status exit-code | |
303 | eshell-last-command-result (cadr result)) | |
304 | (while (< idx eshell-number-of-handles) | |
305 | (let ((handles (or handles eshell-current-handles))) | |
306 | (when (aref handles idx) | |
307 | (setcdr (aref handles idx) | |
308 | (1- (cdr (aref handles idx)))) | |
309 | (when (= (cdr (aref handles idx)) 0) | |
310 | (let ((target (car (aref handles idx)))) | |
311 | (if (not (listp target)) | |
312 | (eshell-close-target target (= exit-code 0)) | |
313 | (while target | |
314 | (eshell-close-target (car target) (= exit-code 0)) | |
315 | (setq target (cdr target))))) | |
316 | (setcar (aref handles idx) nil)))) | |
317 | (setq idx (1+ idx))) | |
318 | nil)) | |
319 | ||
320 | (defun eshell-kill-append (string) | |
321 | "Call `kill-append' with STRING, if it is indeed a string." | |
322 | (if (stringp string) | |
323 | (kill-append string nil))) | |
324 | ||
325 | (defun eshell-clipboard-append (string) | |
326 | "Call `kill-append' with STRING, if it is indeed a string." | |
327 | (if (stringp string) | |
328 | (let ((x-select-enable-clipboard t)) | |
329 | (kill-append string nil)))) | |
330 | ||
331 | (defun eshell-get-target (target &optional mode) | |
332 | "Convert TARGET, which is a raw argument, into a valid output target. | |
ca7aae91 JW |
333 | MODE is either `overwrite', `append' or `insert'; if it is omitted or nil, |
334 | it defaults to `insert'." | |
affbf647 GM |
335 | (setq mode (or mode 'insert)) |
336 | (cond | |
337 | ((stringp target) | |
338 | (let ((redir (assoc target eshell-virtual-targets))) | |
e1703ba9 JW |
339 | (if redir |
340 | (if (nth 2 redir) | |
341 | (funcall (nth 1 redir) mode) | |
342 | (nth 1 redir)) | |
343 | (let* ((exists (get-file-buffer target)) | |
344 | (buf (find-file-noselect target t))) | |
345 | (with-current-buffer buf | |
346 | (if buffer-read-only | |
347 | (error "Cannot write to read-only file `%s'" target)) | |
348 | (set (make-local-variable 'eshell-output-file-buffer) | |
349 | (if (eq exists buf) 0 t)) | |
350 | (cond ((eq mode 'overwrite) | |
351 | (erase-buffer)) | |
352 | ((eq mode 'append) | |
353 | (goto-char (point-max)))) | |
354 | (point-marker)))))) | |
355 | ||
affbf647 GM |
356 | ((or (bufferp target) |
357 | (and (boundp 'eshell-buffer-shorthand) | |
358 | (symbol-value 'eshell-buffer-shorthand) | |
9c041409 JW |
359 | (symbolp target) |
360 | (not (memq target '(t nil))))) | |
affbf647 GM |
361 | (let ((buf (if (bufferp target) |
362 | target | |
363 | (get-buffer-create | |
364 | (symbol-name target))))) | |
365 | (with-current-buffer buf | |
366 | (cond ((eq mode 'overwrite) | |
367 | (erase-buffer)) | |
368 | ((eq mode 'append) | |
369 | (goto-char (point-max)))) | |
370 | (point-marker)))) | |
e1703ba9 JW |
371 | |
372 | ((functionp target) nil) | |
373 | ||
affbf647 GM |
374 | ((symbolp target) |
375 | (if (eq mode 'overwrite) | |
376 | (set target nil)) | |
377 | target) | |
e1703ba9 | 378 | |
ca7aae91 | 379 | ((or (eshell-processp target) |
affbf647 GM |
380 | (markerp target)) |
381 | target) | |
e1703ba9 | 382 | |
affbf647 | 383 | (t |
5b423d48 | 384 | (error "Invalid redirection target: %s" |
affbf647 GM |
385 | (eshell-stringify target))))) |
386 | ||
1a32899d | 387 | (defvar grep-null-device) |
affbf647 GM |
388 | |
389 | (defun eshell-set-output-handle (index mode &optional target) | |
390 | "Set handle INDEX, using MODE, to point to TARGET." | |
391 | (when target | |
392 | (if (and (stringp target) | |
393 | (or (cond | |
394 | ((boundp 'null-device) | |
395 | (string= target null-device)) | |
396 | ((boundp 'grep-null-device) | |
397 | (string= target grep-null-device)) | |
398 | (t nil)) | |
399 | (string= target "/dev/null"))) | |
400 | (aset eshell-current-handles index nil) | |
401 | (let ((where (eshell-get-target target mode)) | |
402 | (current (car (aref eshell-current-handles index)))) | |
403 | (if (and (listp current) | |
404 | (not (member where current))) | |
405 | (setq current (append current (list where))) | |
2c762cee | 406 | (setq current (list where))) |
affbf647 GM |
407 | (if (not (aref eshell-current-handles index)) |
408 | (aset eshell-current-handles index (cons nil 1))) | |
409 | (setcar (aref eshell-current-handles index) current))))) | |
410 | ||
411 | (defun eshell-interactive-output-p () | |
412 | "Return non-nil if current handles are bound for interactive display." | |
413 | (and (eq (car (aref eshell-current-handles | |
414 | eshell-output-handle)) t) | |
415 | (eq (car (aref eshell-current-handles | |
416 | eshell-error-handle)) t))) | |
417 | ||
418 | (defvar eshell-print-queue nil) | |
419 | (defvar eshell-print-queue-count -1) | |
420 | ||
5153ac72 GM |
421 | (defsubst eshell-print (object) |
422 | "Output OBJECT to the standard output handle." | |
423 | (eshell-output-object object eshell-output-handle)) | |
424 | ||
affbf647 GM |
425 | (defun eshell-flush (&optional reset-p) |
426 | "Flush out any lines that have been queued for printing. | |
427 | Must be called before printing begins with -1 as its argument, and | |
428 | after all printing is over with no argument." | |
429 | (ignore | |
430 | (if reset-p | |
431 | (setq eshell-print-queue nil | |
432 | eshell-print-queue-count reset-p) | |
433 | (if eshell-print-queue | |
434 | (eshell-print eshell-print-queue)) | |
435 | (eshell-flush 0)))) | |
436 | ||
437 | (defun eshell-init-print-buffer () | |
438 | "Initialize the buffered printing queue." | |
439 | (eshell-flush -1)) | |
440 | ||
441 | (defun eshell-buffered-print (&rest strings) | |
442 | "A buffered print -- *for strings only*." | |
443 | (if (< eshell-print-queue-count 0) | |
444 | (progn | |
445 | (eshell-print (apply 'concat strings)) | |
446 | (setq eshell-print-queue-count 0)) | |
447 | (if (= eshell-print-queue-count eshell-print-queue-size) | |
448 | (eshell-flush)) | |
449 | (setq eshell-print-queue | |
450 | (concat eshell-print-queue (apply 'concat strings)) | |
451 | eshell-print-queue-count (1+ eshell-print-queue-count)))) | |
452 | ||
affbf647 | 453 | (defsubst eshell-error (object) |
ca7aae91 | 454 | "Output OBJECT to the standard error handle." |
affbf647 GM |
455 | (eshell-output-object object eshell-error-handle)) |
456 | ||
457 | (defsubst eshell-errorn (object) | |
ca7aae91 | 458 | "Output OBJECT followed by a newline to the standard error handle." |
affbf647 GM |
459 | (eshell-error object) |
460 | (eshell-error "\n")) | |
461 | ||
462 | (defsubst eshell-printn (object) | |
ca7aae91 | 463 | "Output OBJECT followed by a newline to the standard output handle." |
affbf647 GM |
464 | (eshell-print object) |
465 | (eshell-print "\n")) | |
466 | ||
467 | (defun eshell-output-object-to-target (object target) | |
468 | "Insert OBJECT into TARGET. | |
469 | Returns what was actually sent, or nil if nothing was sent." | |
470 | (cond | |
471 | ((functionp target) | |
472 | (funcall target object)) | |
473 | ||
474 | ((symbolp target) | |
475 | (if (eq target t) ; means "print to display" | |
476 | (eshell-output-filter nil (eshell-stringify object)) | |
477 | (if (not (symbol-value target)) | |
478 | (set target object) | |
479 | (setq object (eshell-stringify object)) | |
480 | (if (not (stringp (symbol-value target))) | |
481 | (set target (eshell-stringify | |
482 | (symbol-value target)))) | |
483 | (set target (concat (symbol-value target) object))))) | |
484 | ||
485 | ((markerp target) | |
486 | (if (buffer-live-p (marker-buffer target)) | |
487 | (with-current-buffer (marker-buffer target) | |
488 | (let ((moving (= (point) target))) | |
489 | (save-excursion | |
490 | (goto-char target) | |
e1703ba9 JW |
491 | (unless (stringp object) |
492 | (setq object (eshell-stringify object))) | |
affbf647 GM |
493 | (insert-and-inherit object) |
494 | (set-marker target (point-marker))) | |
495 | (if moving | |
496 | (goto-char target)))))) | |
497 | ||
ca7aae91 | 498 | ((eshell-processp target) |
affbf647 | 499 | (when (eq (process-status target) 'run) |
e1703ba9 JW |
500 | (unless (stringp object) |
501 | (setq object (eshell-stringify object))) | |
affbf647 GM |
502 | (process-send-string target object))) |
503 | ||
504 | ((consp target) | |
505 | (apply (car target) object (cdr target)))) | |
506 | object) | |
507 | ||
508 | (defun eshell-output-object (object &optional handle-index handles) | |
509 | "Insert OBJECT, using HANDLE-INDEX specifically)." | |
510 | (let ((target (car (aref (or handles eshell-current-handles) | |
511 | (or handle-index eshell-output-handle))))) | |
512 | (if (and target (not (listp target))) | |
513 | (eshell-output-object-to-target object target) | |
514 | (while target | |
515 | (eshell-output-object-to-target object (car target)) | |
516 | (setq target (cdr target)))))) | |
517 | ||
cbee283d | 518 | ;; arch-tag: 9ca2080f-d5e0-4b26-aa0b-d59194a905a2 |
affbf647 | 519 | ;;; esh-io.el ends here |