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60370d40 | 1 | ;;; esh-io.el --- I/O management |
affbf647 | 2 | |
f2e3589a | 3 | ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, |
8b72699e | 4 | ;; 2005, 2006, 2007, 2008 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 | ||
5153ac72 GM |
58 | (provide 'esh-io) |
59 | ||
60 | (eval-when-compile (require 'eshell)) | |
61 | ||
62 | (defgroup eshell-io nil | |
63 | "Eshell's I/O management code provides a scheme for treating many | |
64 | different kinds of objects -- symbols, files, buffers, etc. -- as | |
65 | though they were files." | |
66 | :tag "I/O management" | |
67 | :group 'eshell) | |
68 | ||
affbf647 GM |
69 | ;;; User Variables: |
70 | ||
71 | (defcustom eshell-io-load-hook '(eshell-io-initialize) | |
72 | "*A hook that gets run when `eshell-io' is loaded." | |
73 | :type 'hook | |
74 | :group 'eshell-io) | |
75 | ||
76 | (defcustom eshell-number-of-handles 3 | |
77 | "*The number of file handles that eshell supports. | |
78 | Currently this is standard input, output and error. But even all of | |
79 | these Emacs does not currently support with asynchronous processes | |
80 | \(which is what eshell uses so that you can continue doing work in | |
81 | other buffers) ." | |
82 | :type 'integer | |
83 | :group 'eshell-io) | |
84 | ||
85 | (defcustom eshell-output-handle 1 | |
86 | "*The index of the standard output handle." | |
87 | :type 'integer | |
88 | :group 'eshell-io) | |
89 | ||
90 | (defcustom eshell-error-handle 2 | |
91 | "*The index of the standard error handle." | |
92 | :type 'integer | |
93 | :group 'eshell-io) | |
94 | ||
95 | (defcustom eshell-buffer-shorthand nil | |
96 | "*If non-nil, a symbol name can be used for a buffer in redirection. | |
97 | If nil, redirecting to a buffer requires buffer name syntax. If this | |
98 | variable is set, redirection directly to Lisp symbols will be | |
99 | impossible. | |
100 | ||
101 | Example: | |
102 | ||
103 | echo hello > '*scratch* ; works if `eshell-buffer-shorthand' is t | |
104 | echo hello > #<buffer *scratch*> ; always works" | |
105 | :type 'boolean | |
106 | :group 'eshell-io) | |
107 | ||
108 | (defcustom eshell-print-queue-size 5 | |
109 | "*The size of the print queue, for doing buffered printing. | |
110 | This is basically a speed enhancement, to avoid blocking the Lisp code | |
111 | from executing while Emacs is redisplaying." | |
112 | :type 'integer | |
113 | :group 'eshell-io) | |
114 | ||
115 | (defcustom eshell-virtual-targets | |
116 | '(("/dev/eshell" eshell-interactive-print nil) | |
117 | ("/dev/kill" (lambda (mode) | |
118 | (if (eq mode 'overwrite) | |
119 | (kill-new "")) | |
120 | 'eshell-kill-append) t) | |
121 | ("/dev/clip" (lambda (mode) | |
122 | (if (eq mode 'overwrite) | |
123 | (let ((x-select-enable-clipboard t)) | |
124 | (kill-new ""))) | |
125 | 'eshell-clipboard-append) t)) | |
126 | "*Map virtual devices name to Emacs Lisp functions. | |
127 | If the user specifies any of the filenames above as a redirection | |
128 | target, the function in the second element will be called. | |
129 | ||
130 | If the third element is non-nil, the redirection mode is passed as an | |
131 | argument (which is the symbol `overwrite', `append' or `insert'), and | |
132 | the function is expected to return another function -- which is the | |
133 | output function. Otherwise, the second element itself is the output | |
134 | function. | |
135 | ||
ca7aae91 JW |
136 | The output function is then called repeatedly with single strings, |
137 | which represents successive pieces of the output of the command, until nil | |
affbf647 GM |
138 | is passed, meaning EOF. |
139 | ||
140 | NOTE: /dev/null is handled specially as a virtual target, and should | |
141 | not be added to this variable." | |
142 | :type '(repeat | |
143 | (list (string :tag "Target") | |
144 | function | |
145 | (choice (const :tag "Func returns output-func" t) | |
146 | (const :tag "Func is output-func" nil)))) | |
147 | :group 'eshell-io) | |
148 | ||
149 | (put 'eshell-virtual-targets 'risky-local-variable t) | |
150 | ||
151 | ;;; Internal Variables: | |
152 | ||
153 | (defvar eshell-current-handles nil) | |
154 | ||
155 | (defvar eshell-last-command-status 0 | |
156 | "The exit code from the last command. 0 if successful.") | |
157 | ||
158 | (defvar eshell-last-command-result nil | |
159 | "The result of the last command. Not related to success.") | |
160 | ||
161 | (defvar eshell-output-file-buffer nil | |
162 | "If non-nil, the current buffer is a file output buffer.") | |
163 | ||
164 | (defvar eshell-print-count) | |
165 | (defvar eshell-current-redirections) | |
166 | ||
167 | ;;; Functions: | |
168 | ||
169 | (defun eshell-io-initialize () | |
170 | "Initialize the I/O subsystem code." | |
affbf647 GM |
171 | (add-hook 'eshell-parse-argument-hook |
172 | 'eshell-parse-redirection nil t) | |
173 | (make-local-variable 'eshell-current-redirections) | |
affbf647 GM |
174 | (add-hook 'eshell-pre-rewrite-command-hook |
175 | 'eshell-strip-redirections nil t) | |
affbf647 GM |
176 | (add-hook 'eshell-post-rewrite-command-hook |
177 | 'eshell-apply-redirections nil t)) | |
178 | ||
179 | (defun eshell-parse-redirection () | |
180 | "Parse an output redirection, such as '2>'." | |
181 | (if (and (not eshell-current-quoted) | |
182 | (looking-at "\\([0-9]\\)?\\(<\\|>+\\)&?\\([0-9]\\)?\\s-*")) | |
183 | (if eshell-current-argument | |
184 | (eshell-finish-arg) | |
185 | (let ((sh (match-string 1)) | |
186 | (oper (match-string 2)) | |
187 | ; (th (match-string 3)) | |
188 | ) | |
189 | (if (string= oper "<") | |
190 | (error "Eshell does not support input redirection")) | |
191 | (eshell-finish-arg | |
192 | (prog1 | |
193 | (list 'eshell-set-output-handle | |
6b0e3e4d | 194 | (or (and sh (string-to-number sh)) 1) |
affbf647 GM |
195 | (list 'quote |
196 | (aref [overwrite append insert] | |
197 | (1- (length oper))))) | |
198 | (goto-char (match-end 0)))))))) | |
199 | ||
200 | (defun eshell-strip-redirections (terms) | |
201 | "Rewrite any output redirections in TERMS." | |
202 | (setq eshell-current-redirections (list t)) | |
203 | (let ((tl terms) | |
204 | (tt (cdr terms))) | |
205 | (while tt | |
206 | (if (not (and (consp (car tt)) | |
207 | (eq (caar tt) 'eshell-set-output-handle))) | |
208 | (setq tt (cdr tt) | |
209 | tl (cdr tl)) | |
210 | (unless (cdr tt) | |
211 | (error "Missing redirection target")) | |
212 | (nconc eshell-current-redirections | |
213 | (list (list 'ignore | |
214 | (append (car tt) (list (cadr tt)))))) | |
215 | (setcdr tl (cddr tt)) | |
216 | (setq tt (cddr tt)))) | |
217 | (setq eshell-current-redirections | |
218 | (cdr eshell-current-redirections)))) | |
219 | ||
220 | (defun eshell-apply-redirections (cmdsym) | |
221 | "Apply any redirection which were specified for COMMAND." | |
222 | (if eshell-current-redirections | |
223 | (set cmdsym | |
224 | (append (list 'progn) | |
225 | eshell-current-redirections | |
226 | (list (symbol-value cmdsym)))))) | |
227 | ||
228 | (defun eshell-create-handles | |
229 | (standard-output output-mode &optional standard-error error-mode) | |
230 | "Create a new set of file handles for a command. | |
231 | The default location for standard output and standard error will go to | |
ca7aae91 JW |
232 | STANDARD-OUTPUT and STANDARD-ERROR, respectively. |
233 | OUTPUT-MODE and ERROR-MODE are either `overwrite', `append' or `insert'; | |
234 | a nil value of mode defaults to `insert'." | |
affbf647 GM |
235 | (let ((handles (make-vector eshell-number-of-handles nil)) |
236 | (output-target (eshell-get-target standard-output output-mode)) | |
237 | (error-target (eshell-get-target standard-error error-mode))) | |
238 | (aset handles eshell-output-handle (cons output-target 1)) | |
239 | (if standard-error | |
240 | (aset handles eshell-error-handle (cons error-target 1)) | |
241 | (aset handles eshell-error-handle (cons output-target 1))) | |
242 | handles)) | |
243 | ||
244 | (defun eshell-protect-handles (handles) | |
245 | "Protect the handles in HANDLES from a being closed." | |
246 | (let ((idx 0)) | |
247 | (while (< idx eshell-number-of-handles) | |
248 | (if (aref handles idx) | |
249 | (setcdr (aref handles idx) | |
250 | (1+ (cdr (aref handles idx))))) | |
251 | (setq idx (1+ idx)))) | |
252 | handles) | |
253 | ||
254 | (defun eshell-close-target (target status) | |
255 | "Close an output TARGET, passing STATUS as the result. | |
256 | STATUS should be non-nil on successful termination of the output." | |
257 | (cond | |
258 | ((symbolp target) nil) | |
259 | ||
260 | ;; If we were redirecting to a file, save the file and close the | |
261 | ;; buffer. | |
262 | ((markerp target) | |
263 | (let ((buf (marker-buffer target))) | |
264 | (when buf ; somebody's already killed it! | |
265 | (save-current-buffer | |
266 | (set-buffer buf) | |
267 | (when eshell-output-file-buffer | |
268 | (save-buffer) | |
269 | (when (eq eshell-output-file-buffer t) | |
270 | (or status (set-buffer-modified-p nil)) | |
271 | (kill-buffer buf))))))) | |
272 | ||
273 | ;; If we're redirecting to a process (via a pipe, or process | |
274 | ;; redirection), send it EOF so that it knows we're finished. | |
ca7aae91 | 275 | ((eshell-processp target) |
affbf647 GM |
276 | (if (eq (process-status target) 'run) |
277 | (process-send-eof target))) | |
278 | ||
279 | ;; A plain function redirection needs no additional arguments | |
280 | ;; passed. | |
281 | ((functionp target) | |
282 | (funcall target status)) | |
283 | ||
284 | ;; But a more complicated function redirection (which can only | |
285 | ;; happen with aliases at the moment) has arguments that need to be | |
286 | ;; passed along with it. | |
287 | ((consp target) | |
288 | (apply (car target) status (cdr target))))) | |
289 | ||
290 | (defun eshell-close-handles (exit-code &optional result handles) | |
291 | "Close all of the current handles, taking refcounts into account. | |
292 | EXIT-CODE is the process exit code; mainly, it is zero, if the command | |
293 | completed successfully. RESULT is the quoted value of the last | |
294 | command. If nil, then the meta variables for keeping track of the | |
295 | last execution result should not be changed." | |
296 | (let ((idx 0)) | |
297 | (assert (or (not result) (eq (car result) 'quote))) | |
298 | (setq eshell-last-command-status exit-code | |
299 | eshell-last-command-result (cadr result)) | |
300 | (while (< idx eshell-number-of-handles) | |
301 | (let ((handles (or handles eshell-current-handles))) | |
302 | (when (aref handles idx) | |
303 | (setcdr (aref handles idx) | |
304 | (1- (cdr (aref handles idx)))) | |
305 | (when (= (cdr (aref handles idx)) 0) | |
306 | (let ((target (car (aref handles idx)))) | |
307 | (if (not (listp target)) | |
308 | (eshell-close-target target (= exit-code 0)) | |
309 | (while target | |
310 | (eshell-close-target (car target) (= exit-code 0)) | |
311 | (setq target (cdr target))))) | |
312 | (setcar (aref handles idx) nil)))) | |
313 | (setq idx (1+ idx))) | |
314 | nil)) | |
315 | ||
316 | (defun eshell-kill-append (string) | |
317 | "Call `kill-append' with STRING, if it is indeed a string." | |
318 | (if (stringp string) | |
319 | (kill-append string nil))) | |
320 | ||
321 | (defun eshell-clipboard-append (string) | |
322 | "Call `kill-append' with STRING, if it is indeed a string." | |
323 | (if (stringp string) | |
324 | (let ((x-select-enable-clipboard t)) | |
325 | (kill-append string nil)))) | |
326 | ||
327 | (defun eshell-get-target (target &optional mode) | |
328 | "Convert TARGET, which is a raw argument, into a valid output target. | |
ca7aae91 JW |
329 | MODE is either `overwrite', `append' or `insert'; if it is omitted or nil, |
330 | it defaults to `insert'." | |
affbf647 GM |
331 | (setq mode (or mode 'insert)) |
332 | (cond | |
333 | ((stringp target) | |
334 | (let ((redir (assoc target eshell-virtual-targets))) | |
e1703ba9 JW |
335 | (if redir |
336 | (if (nth 2 redir) | |
337 | (funcall (nth 1 redir) mode) | |
338 | (nth 1 redir)) | |
339 | (let* ((exists (get-file-buffer target)) | |
340 | (buf (find-file-noselect target t))) | |
341 | (with-current-buffer buf | |
342 | (if buffer-read-only | |
343 | (error "Cannot write to read-only file `%s'" target)) | |
344 | (set (make-local-variable 'eshell-output-file-buffer) | |
345 | (if (eq exists buf) 0 t)) | |
346 | (cond ((eq mode 'overwrite) | |
347 | (erase-buffer)) | |
348 | ((eq mode 'append) | |
349 | (goto-char (point-max)))) | |
350 | (point-marker)))))) | |
351 | ||
affbf647 GM |
352 | ((or (bufferp target) |
353 | (and (boundp 'eshell-buffer-shorthand) | |
354 | (symbol-value 'eshell-buffer-shorthand) | |
9c041409 JW |
355 | (symbolp target) |
356 | (not (memq target '(t nil))))) | |
affbf647 GM |
357 | (let ((buf (if (bufferp target) |
358 | target | |
359 | (get-buffer-create | |
360 | (symbol-name target))))) | |
361 | (with-current-buffer buf | |
362 | (cond ((eq mode 'overwrite) | |
363 | (erase-buffer)) | |
364 | ((eq mode 'append) | |
365 | (goto-char (point-max)))) | |
366 | (point-marker)))) | |
e1703ba9 JW |
367 | |
368 | ((functionp target) nil) | |
369 | ||
affbf647 GM |
370 | ((symbolp target) |
371 | (if (eq mode 'overwrite) | |
372 | (set target nil)) | |
373 | target) | |
e1703ba9 | 374 | |
ca7aae91 | 375 | ((or (eshell-processp target) |
affbf647 GM |
376 | (markerp target)) |
377 | target) | |
e1703ba9 | 378 | |
affbf647 | 379 | (t |
5b423d48 | 380 | (error "Invalid redirection target: %s" |
affbf647 GM |
381 | (eshell-stringify target))))) |
382 | ||
383 | (eval-when-compile | |
384 | (defvar grep-null-device)) | |
385 | ||
386 | (defun eshell-set-output-handle (index mode &optional target) | |
387 | "Set handle INDEX, using MODE, to point to TARGET." | |
388 | (when target | |
389 | (if (and (stringp target) | |
390 | (or (cond | |
391 | ((boundp 'null-device) | |
392 | (string= target null-device)) | |
393 | ((boundp 'grep-null-device) | |
394 | (string= target grep-null-device)) | |
395 | (t nil)) | |
396 | (string= target "/dev/null"))) | |
397 | (aset eshell-current-handles index nil) | |
398 | (let ((where (eshell-get-target target mode)) | |
399 | (current (car (aref eshell-current-handles index)))) | |
400 | (if (and (listp current) | |
401 | (not (member where current))) | |
402 | (setq current (append current (list where))) | |
2c762cee | 403 | (setq current (list where))) |
affbf647 GM |
404 | (if (not (aref eshell-current-handles index)) |
405 | (aset eshell-current-handles index (cons nil 1))) | |
406 | (setcar (aref eshell-current-handles index) current))))) | |
407 | ||
408 | (defun eshell-interactive-output-p () | |
409 | "Return non-nil if current handles are bound for interactive display." | |
410 | (and (eq (car (aref eshell-current-handles | |
411 | eshell-output-handle)) t) | |
412 | (eq (car (aref eshell-current-handles | |
413 | eshell-error-handle)) t))) | |
414 | ||
415 | (defvar eshell-print-queue nil) | |
416 | (defvar eshell-print-queue-count -1) | |
417 | ||
5153ac72 GM |
418 | (defsubst eshell-print (object) |
419 | "Output OBJECT to the standard output handle." | |
420 | (eshell-output-object object eshell-output-handle)) | |
421 | ||
affbf647 GM |
422 | (defun eshell-flush (&optional reset-p) |
423 | "Flush out any lines that have been queued for printing. | |
424 | Must be called before printing begins with -1 as its argument, and | |
425 | after all printing is over with no argument." | |
426 | (ignore | |
427 | (if reset-p | |
428 | (setq eshell-print-queue nil | |
429 | eshell-print-queue-count reset-p) | |
430 | (if eshell-print-queue | |
431 | (eshell-print eshell-print-queue)) | |
432 | (eshell-flush 0)))) | |
433 | ||
434 | (defun eshell-init-print-buffer () | |
435 | "Initialize the buffered printing queue." | |
436 | (eshell-flush -1)) | |
437 | ||
438 | (defun eshell-buffered-print (&rest strings) | |
439 | "A buffered print -- *for strings only*." | |
440 | (if (< eshell-print-queue-count 0) | |
441 | (progn | |
442 | (eshell-print (apply 'concat strings)) | |
443 | (setq eshell-print-queue-count 0)) | |
444 | (if (= eshell-print-queue-count eshell-print-queue-size) | |
445 | (eshell-flush)) | |
446 | (setq eshell-print-queue | |
447 | (concat eshell-print-queue (apply 'concat strings)) | |
448 | eshell-print-queue-count (1+ eshell-print-queue-count)))) | |
449 | ||
affbf647 | 450 | (defsubst eshell-error (object) |
ca7aae91 | 451 | "Output OBJECT to the standard error handle." |
affbf647 GM |
452 | (eshell-output-object object eshell-error-handle)) |
453 | ||
454 | (defsubst eshell-errorn (object) | |
ca7aae91 | 455 | "Output OBJECT followed by a newline to the standard error handle." |
affbf647 GM |
456 | (eshell-error object) |
457 | (eshell-error "\n")) | |
458 | ||
459 | (defsubst eshell-printn (object) | |
ca7aae91 | 460 | "Output OBJECT followed by a newline to the standard output handle." |
affbf647 GM |
461 | (eshell-print object) |
462 | (eshell-print "\n")) | |
463 | ||
464 | (defun eshell-output-object-to-target (object target) | |
465 | "Insert OBJECT into TARGET. | |
466 | Returns what was actually sent, or nil if nothing was sent." | |
467 | (cond | |
468 | ((functionp target) | |
469 | (funcall target object)) | |
470 | ||
471 | ((symbolp target) | |
472 | (if (eq target t) ; means "print to display" | |
473 | (eshell-output-filter nil (eshell-stringify object)) | |
474 | (if (not (symbol-value target)) | |
475 | (set target object) | |
476 | (setq object (eshell-stringify object)) | |
477 | (if (not (stringp (symbol-value target))) | |
478 | (set target (eshell-stringify | |
479 | (symbol-value target)))) | |
480 | (set target (concat (symbol-value target) object))))) | |
481 | ||
482 | ((markerp target) | |
483 | (if (buffer-live-p (marker-buffer target)) | |
484 | (with-current-buffer (marker-buffer target) | |
485 | (let ((moving (= (point) target))) | |
486 | (save-excursion | |
487 | (goto-char target) | |
e1703ba9 JW |
488 | (unless (stringp object) |
489 | (setq object (eshell-stringify object))) | |
affbf647 GM |
490 | (insert-and-inherit object) |
491 | (set-marker target (point-marker))) | |
492 | (if moving | |
493 | (goto-char target)))))) | |
494 | ||
ca7aae91 | 495 | ((eshell-processp target) |
affbf647 | 496 | (when (eq (process-status target) 'run) |
e1703ba9 JW |
497 | (unless (stringp object) |
498 | (setq object (eshell-stringify object))) | |
affbf647 GM |
499 | (process-send-string target object))) |
500 | ||
501 | ((consp target) | |
502 | (apply (car target) object (cdr target)))) | |
503 | object) | |
504 | ||
505 | (defun eshell-output-object (object &optional handle-index handles) | |
506 | "Insert OBJECT, using HANDLE-INDEX specifically)." | |
507 | (let ((target (car (aref (or handles eshell-current-handles) | |
508 | (or handle-index eshell-output-handle))))) | |
509 | (if (and target (not (listp target))) | |
510 | (eshell-output-object-to-target object target) | |
511 | (while target | |
512 | (eshell-output-object-to-target object (car target)) | |
513 | (setq target (cdr target)))))) | |
514 | ||
515 | ;;; Code: | |
516 | ||
cbee283d | 517 | ;; arch-tag: 9ca2080f-d5e0-4b26-aa0b-d59194a905a2 |
affbf647 | 518 | ;;; esh-io.el ends here |