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60370d40 | 1 | ;;; esh-var.el --- handling of variables |
affbf647 | 2 | |
f2e3589a | 3 | ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, |
ceb4c4d3 | 4 | ;; 2005, 2006 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 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation; either version 2, or (at your option) | |
13 | ;; any later version. | |
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 | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
3a35cf56 LK |
22 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
23 | ;; Boston, MA 02110-1301, USA. | |
affbf647 GM |
24 | |
25 | (provide 'esh-var) | |
26 | ||
27 | (eval-when-compile (require 'esh-maint)) | |
28 | ||
29 | (defgroup eshell-var nil | |
30 | "Variable interpolation is introduced whenever the '$' character | |
31 | appears unquoted in any argument (except when that argument is | |
eabc24ca | 32 | surrounded by single quotes). It may be used to interpolate a |
affbf647 GM |
33 | variable value, a subcommand, or even the result of a Lisp form." |
34 | :tag "Variable handling" | |
35 | :group 'eshell) | |
36 | ||
37 | ;;; Commentary: | |
38 | ||
39 | ;; These are the possible variable interpolation syntaxes. Also keep | |
40 | ;; in mind that if an argument looks like a number, it will be | |
41 | ;; converted to a number. This is not significant when invoking | |
42 | ;; external commands, but it's important when calling Lisp functions. | |
43 | ;; | |
44 | ;; $VARIABLE | |
45 | ;; | |
46 | ;; Interval the value of an environment variable, or a Lisp variable | |
47 | ;; | |
48 | ;; $ALSO-VAR | |
49 | ;; | |
50 | ;; "-" is a legal part of a variable name. | |
51 | ;; | |
52 | ;; $<MYVAR>-TOO | |
53 | ;; | |
54 | ;; Only "MYVAR" is part of the variable name in this case. | |
55 | ;; | |
56 | ;; $#VARIABLE | |
57 | ;; | |
58 | ;; Returns the length of the value of VARIABLE. This could also be | |
59 | ;; done using the `length' Lisp function. | |
60 | ;; | |
61 | ;; $(lisp) | |
62 | ;; | |
63 | ;; Returns result of lisp evaluation. Note: Used alone like this, it | |
64 | ;; is identical to just saying (lisp); but with the variable expansion | |
65 | ;; form, the result may be interpolated a larger string, such as | |
66 | ;; '$(lisp)/other'. | |
67 | ;; | |
68 | ;; ${command} | |
69 | ;; | |
70 | ;; Returns the value of an eshell subcommand. See the note above | |
71 | ;; regarding Lisp evaluations. | |
72 | ;; | |
73 | ;; $ANYVAR[10] | |
74 | ;; | |
75 | ;; Return the 10th element of ANYVAR. If ANYVAR's value is a string, | |
76 | ;; it will be split in order to make it a list. The splitting will | |
77 | ;; occur at whitespace. | |
78 | ;; | |
79 | ;; $ANYVAR[: 10] | |
80 | ;; | |
81 | ;; As above, except that splitting occurs at the colon now. | |
82 | ;; | |
83 | ;; $ANYVAR[: 10 20] | |
84 | ;; | |
85 | ;; As above, but instead of returning just a string, it now returns a | |
86 | ;; list of two strings. If the result is being interpolated into a | |
87 | ;; larger string, this list will be flattened into one big string, | |
88 | ;; with each element separated by a space. | |
89 | ;; | |
90 | ;; $ANYVAR["\\\\" 10] | |
91 | ;; | |
92 | ;; Separate on backslash characters. Actually, the first argument -- | |
93 | ;; if it doesn't have the form of a number, or a plain variable name | |
94 | ;; -- can be any regular expression. So to split on numbers, use | |
95 | ;; '$ANYVAR["[0-9]+" 10 20]'. | |
96 | ;; | |
97 | ;; $ANYVAR[hello] | |
98 | ;; | |
99 | ;; Calls `assoc' on ANYVAR with 'hello', expecting it to be an alist. | |
100 | ;; | |
101 | ;; $#ANYVAR[hello] | |
102 | ;; | |
103 | ;; Returns the length of the cdr of the element of ANYVAR who car is | |
104 | ;; equal to "hello". | |
105 | ;; | |
106 | ;; There are also a few special variables defined by Eshell. '$$' is | |
107 | ;; the value of the last command (t or nil, in the case of an external | |
108 | ;; command). This makes it possible to chain results: | |
109 | ;; | |
110 | ;; /tmp $ echo /var/spool/mail/johnw | |
111 | ;; /var/spool/mail/johnw | |
112 | ;; /tmp $ dirname $$ | |
113 | ;; /var/spool/mail/ | |
114 | ;; /tmp $ cd $$ | |
115 | ;; /var/spool/mail $ | |
116 | ;; | |
117 | ;; '$_' refers to the last argument of the last command. And $? | |
118 | ;; contains the exit code of the last command (0 or 1 for Lisp | |
119 | ;; functions, based on successful completion). | |
120 | ||
121 | (require 'env) | |
122 | (require 'ring) | |
123 | ||
124 | ;;; User Variables: | |
125 | ||
126 | (defcustom eshell-var-load-hook '(eshell-var-initialize) | |
127 | "*A list of functions to call when loading `eshell-var'." | |
128 | :type 'hook | |
129 | :group 'eshell-var) | |
130 | ||
131 | (defcustom eshell-prefer-lisp-variables nil | |
132 | "*If non-nil, prefer Lisp variables to environment variables." | |
133 | :type 'boolean | |
134 | :group 'eshell-var) | |
135 | ||
136 | (defcustom eshell-complete-export-definition t | |
137 | "*If non-nil, completing names for `export' shows current definition." | |
138 | :type 'boolean | |
139 | :group 'eshell-var) | |
140 | ||
6995786d JW |
141 | (defcustom eshell-modify-global-environment nil |
142 | "*If non-nil, using `export' changes Emacs's global environment." | |
143 | :type 'boolean | |
144 | :group 'eshell-var) | |
145 | ||
affbf647 GM |
146 | (defcustom eshell-variable-name-regexp "[A-Za-z0-9_-]+" |
147 | "*A regexp identifying what constitutes a variable name reference. | |
148 | Note that this only applies for '$NAME'. If the syntax '$<NAME>' is | |
149 | used, then NAME can contain any character, including angle brackets, | |
150 | if they are quoted with a backslash." | |
151 | :type 'regexp | |
152 | :group 'eshell-var) | |
153 | ||
154 | (defcustom eshell-variable-aliases-list | |
155 | '(;; for eshell.el | |
156 | ("COLUMNS" (lambda (indices) (window-width)) t) | |
157 | ("LINES" (lambda (indices) (window-height)) t) | |
158 | ||
159 | ;; for eshell-cmd.el | |
160 | ("_" (lambda (indices) | |
161 | (if (not indices) | |
162 | (car (last eshell-last-arguments)) | |
163 | (eshell-apply-indices eshell-last-arguments | |
164 | indices)))) | |
165 | ("?" eshell-last-command-status) | |
166 | ("$" eshell-last-command-result) | |
167 | ("0" eshell-command-name) | |
168 | ("1" (lambda (indices) (nth 0 eshell-command-arguments))) | |
169 | ("2" (lambda (indices) (nth 1 eshell-command-arguments))) | |
170 | ("3" (lambda (indices) (nth 2 eshell-command-arguments))) | |
171 | ("4" (lambda (indices) (nth 3 eshell-command-arguments))) | |
172 | ("5" (lambda (indices) (nth 4 eshell-command-arguments))) | |
173 | ("6" (lambda (indices) (nth 5 eshell-command-arguments))) | |
174 | ("7" (lambda (indices) (nth 6 eshell-command-arguments))) | |
175 | ("8" (lambda (indices) (nth 7 eshell-command-arguments))) | |
176 | ("9" (lambda (indices) (nth 8 eshell-command-arguments))) | |
177 | ("*" (lambda (indices) | |
178 | (if (not indices) | |
179 | eshell-command-arguments | |
180 | (eshell-apply-indices eshell-command-arguments | |
181 | indices))))) | |
182 | "*This list provides aliasing for variable references. | |
183 | It is very similar in concept to what `eshell-user-aliases-list' does | |
184 | for commands. Each member of this defines defines the name of a | |
185 | command, and the Lisp value to return for that variable if it is | |
186 | accessed via the syntax '$NAME'. | |
187 | ||
188 | If the value is a function, that function will be called with two | |
189 | arguments: the list of the indices that was used in the reference, and | |
190 | whether the user is requesting the length of the ultimate element. | |
191 | For example, a reference of '$NAME[10][20]' would result in the | |
192 | function for alias `NAME' being called (assuming it were aliased to a | |
193 | function), and the arguments passed to this function would be the list | |
194 | '(10 20)', and nil." | |
195 | :type '(repeat (list string sexp | |
196 | (choice (const :tag "Copy to environment" t) | |
197 | (const :tag "Use only in Eshell" nil)))) | |
198 | :group 'eshell-var) | |
199 | ||
200 | (put 'eshell-variable-aliases-list 'risky-local-variable t) | |
201 | ||
202 | ;;; Functions: | |
203 | ||
204 | (defun eshell-var-initialize () | |
205 | "Initialize the variable handle code." | |
206 | ;; Break the association with our parent's environment. Otherwise, | |
207 | ;; changing a variable will affect all of Emacs. | |
6995786d JW |
208 | (unless eshell-modify-global-environment |
209 | (set (make-local-variable 'process-environment) | |
210 | (eshell-copy-environment))) | |
affbf647 GM |
211 | |
212 | (define-key eshell-command-map [(meta ?v)] 'eshell-insert-envvar) | |
213 | ||
214 | (set (make-local-variable 'eshell-special-chars-inside-quoting) | |
215 | (append eshell-special-chars-inside-quoting '(?$))) | |
216 | (set (make-local-variable 'eshell-special-chars-outside-quoting) | |
217 | (append eshell-special-chars-outside-quoting '(?$))) | |
218 | ||
affbf647 GM |
219 | (add-hook 'eshell-parse-argument-hook 'eshell-interpolate-variable t t) |
220 | ||
affbf647 GM |
221 | (add-hook 'eshell-prepare-command-hook |
222 | 'eshell-handle-local-variables nil t) | |
223 | ||
224 | (when (eshell-using-module 'eshell-cmpl) | |
affbf647 GM |
225 | (add-hook 'pcomplete-try-first-hook |
226 | 'eshell-complete-variable-reference nil t) | |
227 | (add-hook 'pcomplete-try-first-hook | |
228 | 'eshell-complete-variable-assignment nil t))) | |
229 | ||
230 | (defun eshell-handle-local-variables () | |
231 | "Allow for the syntax 'VAR=val <command> <args>'." | |
232 | ;; strip off any null commands, which can only happen if a variable | |
233 | ;; evaluates to nil, such as "$var x", where `var' is nil. The | |
234 | ;; command name in that case becomes `x', for compatibility with | |
235 | ;; most regular shells (the difference is that they do an | |
236 | ;; interpolation pass before the argument parsing pass, but Eshell | |
237 | ;; does both at the same time). | |
238 | (while (and (not eshell-last-command-name) | |
239 | eshell-last-arguments) | |
240 | (setq eshell-last-command-name (car eshell-last-arguments) | |
241 | eshell-last-arguments (cdr eshell-last-arguments))) | |
242 | (let ((setvar "\\`\\([A-Za-z_][A-Za-z0-9_]*\\)=\\(.*\\)\\'") | |
243 | (command (eshell-stringify eshell-last-command-name)) | |
244 | (args eshell-last-arguments)) | |
245 | ;; local variable settings (such as 'CFLAGS=-O2 make') are handled | |
246 | ;; by making the whole command into a subcommand, and calling | |
247 | ;; setenv immediately before the command is invoked. This means | |
248 | ;; that 'BLAH=x cd blah' won't work exactly as expected, but that | |
249 | ;; is by no means a typical use of local environment variables. | |
250 | (if (and command (string-match setvar command)) | |
251 | (throw | |
252 | 'eshell-replace-command | |
253 | (list | |
254 | 'eshell-as-subcommand | |
255 | (append | |
256 | (list 'progn) | |
257 | (let ((l (list t))) | |
258 | (while (string-match setvar command) | |
259 | (nconc | |
260 | l (list | |
261 | (list 'setenv (match-string 1 command) | |
262 | (match-string 2 command) | |
263 | (= (length (match-string 2 command)) 0)))) | |
264 | (setq command (eshell-stringify (car args)) | |
265 | args (cdr args))) | |
266 | (cdr l)) | |
267 | (list (list 'eshell-named-command | |
268 | command (list 'quote args))))))))) | |
269 | ||
270 | (defun eshell-interpolate-variable () | |
271 | "Parse a variable interpolation. | |
272 | This function is explicit for adding to `eshell-parse-argument-hook'." | |
273 | (when (and (eq (char-after) ?$) | |
ca7aae91 | 274 | (/= (1+ (point)) (point-max))) |
affbf647 GM |
275 | (forward-char) |
276 | (list 'eshell-escape-arg | |
277 | (eshell-parse-variable)))) | |
278 | ||
279 | (defun eshell/define (var-alias definition) | |
012d3cb5 | 280 | "Define a VAR-ALIAS using DEFINITION." |
affbf647 GM |
281 | (if (not definition) |
282 | (setq eshell-variable-aliases-list | |
283 | (delq (assoc var-alias eshell-variable-aliases-list) | |
284 | eshell-variable-aliases-list)) | |
285 | (let ((def (assoc var-alias eshell-variable-aliases-list)) | |
286 | (alias-def | |
287 | (list var-alias | |
288 | (list 'quote (if (= (length definition) 1) | |
289 | (car definition) | |
290 | definition))))) | |
291 | (if def | |
292 | (setq eshell-variable-aliases-list | |
293 | (delq (assoc var-alias eshell-variable-aliases-list) | |
294 | eshell-variable-aliases-list))) | |
295 | (setq eshell-variable-aliases-list | |
296 | (cons alias-def | |
297 | eshell-variable-aliases-list)))) | |
298 | nil) | |
299 | ||
300 | (defun eshell/export (&rest sets) | |
a4fd4556 | 301 | "This alias allows the `export' command to act as bash users expect." |
affbf647 | 302 | (while sets |
ca7aae91 JW |
303 | (if (and (stringp (car sets)) |
304 | (string-match "^\\([^=]+\\)=\\(.*\\)" (car sets))) | |
affbf647 GM |
305 | (setenv (match-string 1 (car sets)) |
306 | (match-string 2 (car sets)))) | |
307 | (setq sets (cdr sets)))) | |
308 | ||
79cf8e80 JW |
309 | (defun pcomplete/eshell-mode/export () |
310 | "Completion function for Eshell's `export'." | |
311 | (while (pcomplete-here | |
312 | (if eshell-complete-export-definition | |
313 | process-environment | |
314 | (eshell-envvar-names))))) | |
315 | ||
ca7aae91 JW |
316 | (defun eshell/unset (&rest args) |
317 | "Unset an environment variable." | |
318 | (while args | |
319 | (if (stringp (car args)) | |
320 | (setenv (car args) nil t)) | |
321 | (setq args (cdr args)))) | |
322 | ||
79cf8e80 JW |
323 | (defun pcomplete/eshell-mode/unset () |
324 | "Completion function for Eshell's `unset'." | |
325 | (while (pcomplete-here (eshell-envvar-names)))) | |
affbf647 GM |
326 | |
327 | (defun eshell/setq (&rest args) | |
328 | "Allow command-ish use of `setq'." | |
329 | (let (last-value) | |
330 | (while args | |
331 | (let ((sym (intern (car args))) | |
332 | (val (cadr args))) | |
333 | (setq last-value (set sym val) | |
334 | args (cddr args)))) | |
335 | last-value)) | |
336 | ||
337 | (defun pcomplete/eshell-mode/setq () | |
338 | "Completion function for Eshell's `setq'." | |
339 | (while (and (pcomplete-here (all-completions pcomplete-stub | |
340 | obarray 'boundp)) | |
341 | (pcomplete-here)))) | |
342 | ||
343 | (defun eshell/env (&rest args) | |
344 | "Implemention of `env' in Lisp." | |
345 | (eshell-init-print-buffer) | |
346 | (eshell-eval-using-options | |
347 | "env" args | |
348 | '((?h "help" nil nil "show this usage screen") | |
349 | :external "env" | |
350 | :usage "<no arguments>") | |
351 | (eshell-for setting (sort (eshell-environment-variables) | |
352 | 'string-lessp) | |
353 | (eshell-buffered-print setting "\n")) | |
354 | (eshell-flush))) | |
355 | ||
356 | (defun eshell-insert-envvar (envvar-name) | |
357 | "Insert ENVVAR-NAME into the current buffer at point." | |
358 | (interactive | |
359 | (list (read-envvar-name "Name of environment variable: " t))) | |
360 | (insert-and-inherit "$" envvar-name)) | |
361 | ||
362 | (defun eshell-envvar-names (&optional environment) | |
363 | "Return a list of currently visible environment variable names." | |
364 | (mapcar (function | |
365 | (lambda (x) | |
366 | (substring x 0 (string-match "=" x)))) | |
367 | (or environment process-environment))) | |
368 | ||
369 | (defun eshell-environment-variables () | |
370 | "Return a `process-environment', fully updated. | |
371 | This involves setting any variable aliases which affect the | |
372 | environment, as specified in `eshell-variable-aliases-list'." | |
373 | (let ((process-environment (eshell-copy-environment))) | |
374 | (eshell-for var-alias eshell-variable-aliases-list | |
375 | (if (nth 2 var-alias) | |
376 | (setenv (car var-alias) | |
377 | (eshell-stringify | |
378 | (or (eshell-get-variable (car var-alias)) ""))))) | |
379 | process-environment)) | |
380 | ||
381 | (defun eshell-parse-variable () | |
382 | "Parse the next variable reference at point. | |
383 | The variable name could refer to either an environment variable, or a | |
384 | Lisp variable. The priority order depends on the setting of | |
385 | `eshell-prefer-lisp-variables'. | |
386 | ||
387 | Its purpose is to call `eshell-parse-variable-ref', and then to | |
388 | process any indices that come after the variable reference." | |
389 | (let* ((get-len (when (eq (char-after) ?#) | |
390 | (forward-char) t)) | |
391 | value indices) | |
392 | (setq value (eshell-parse-variable-ref) | |
393 | indices (and (not (eobp)) | |
394 | (eq (char-after) ?\[) | |
395 | (eshell-parse-indices)) | |
396 | value (list 'let | |
397 | (list (list 'indices | |
398 | (list 'quote indices))) | |
399 | value)) | |
400 | (if get-len | |
401 | (list 'length value) | |
402 | value))) | |
403 | ||
404 | (defun eshell-parse-variable-ref () | |
405 | "Eval a variable reference. | |
406 | Returns a Lisp form which, if evaluated, will return the value of the | |
407 | variable. | |
408 | ||
409 | Possible options are: | |
410 | ||
411 | NAME an environment or Lisp variable value | |
412 | <LONG-NAME> disambiguates the length of the name | |
413 | {COMMAND} result of command is variable's value | |
414 | (LISP-FORM) result of Lisp form is variable's value" | |
415 | (let (end) | |
416 | (cond | |
417 | ((eq (char-after) ?{) | |
418 | (let ((end (eshell-find-delimiter ?\{ ?\}))) | |
419 | (if (not end) | |
420 | (throw 'eshell-incomplete ?\{) | |
421 | (prog1 | |
422 | (list 'eshell-convert | |
423 | (list 'eshell-command-to-value | |
424 | (list 'eshell-as-subcommand | |
425 | (eshell-parse-command | |
426 | (cons (1+ (point)) end))))) | |
427 | (goto-char (1+ end)))))) | |
428 | ((memq (char-after) '(?\' ?\")) | |
429 | (let ((name (if (eq (char-after) ?\') | |
430 | (eshell-parse-literal-quote) | |
431 | (eshell-parse-double-quote)))) | |
432 | (if name | |
433 | (list 'eshell-get-variable (eval name) 'indices)))) | |
f1572159 | 434 | ((eq (char-after) ?\<) |
affbf647 GM |
435 | (let ((end (eshell-find-delimiter ?\< ?\>))) |
436 | (if (not end) | |
437 | (throw 'eshell-incomplete ?\<) | |
1ae720ac | 438 | (let* ((temp (make-temp-file temporary-file-directory)) |
affbf647 GM |
439 | (cmd (concat (buffer-substring (1+ (point)) end) |
440 | " > " temp))) | |
441 | (prog1 | |
442 | (list | |
443 | 'let (list (list 'eshell-current-handles | |
444 | (list 'eshell-create-handles temp | |
445 | (list 'quote 'overwrite)))) | |
446 | (list | |
447 | 'progn | |
448 | (list 'eshell-as-subcommand | |
449 | (eshell-parse-command cmd)) | |
450 | (list 'ignore | |
451 | (list 'nconc 'eshell-this-command-hook | |
452 | (list 'list | |
453 | (list 'function | |
454 | (list 'lambda nil | |
455 | (list 'delete-file temp)))))) | |
456 | (list 'quote temp))) | |
457 | (goto-char (1+ end))))))) | |
458 | ((eq (char-after) ?\() | |
459 | (condition-case err | |
460 | (list 'eshell-command-to-value | |
461 | (list 'eshell-lisp-command | |
462 | (list 'quote (read (current-buffer))))) | |
463 | (end-of-file | |
464 | (throw 'eshell-incomplete ?\()))) | |
465 | ((assoc (char-to-string (char-after)) | |
466 | eshell-variable-aliases-list) | |
467 | (forward-char) | |
468 | (list 'eshell-get-variable | |
469 | (char-to-string (char-before)) 'indices)) | |
470 | ((looking-at eshell-variable-name-regexp) | |
471 | (prog1 | |
472 | (list 'eshell-get-variable (match-string 0) 'indices) | |
473 | (goto-char (match-end 0)))) | |
474 | (t | |
475 | (error "Invalid variable reference"))))) | |
476 | ||
477 | (eshell-deftest var interp-cmd | |
478 | "Interpolate command result" | |
479 | (eshell-command-result-p "+ ${+ 1 2} 3" "6\n")) | |
480 | ||
481 | (eshell-deftest var interp-lisp | |
482 | "Interpolate Lisp form evalution" | |
483 | (eshell-command-result-p "+ $(+ 1 2) 3" "6\n")) | |
484 | ||
485 | (eshell-deftest var interp-concat | |
486 | "Interpolate and concat command" | |
487 | (eshell-command-result-p "+ ${+ 1 2}3 3" "36\n")) | |
488 | ||
489 | (eshell-deftest var interp-concat-lisp | |
490 | "Interpolate and concat Lisp form" | |
491 | (eshell-command-result-p "+ $(+ 1 2)3 3" "36\n")) | |
492 | ||
493 | (eshell-deftest var interp-concat2 | |
494 | "Interpolate and concat two commands" | |
495 | (eshell-command-result-p "+ ${+ 1 2}${+ 1 2} 3" "36\n")) | |
496 | ||
497 | (eshell-deftest var interp-concat-lisp2 | |
498 | "Interpolate and concat two Lisp forms" | |
499 | (eshell-command-result-p "+ $(+ 1 2)$(+ 1 2) 3" "36\n")) | |
500 | ||
501 | (defun eshell-parse-indices () | |
502 | "Parse and return a list of list of indices." | |
503 | (let (indices) | |
504 | (while (eq (char-after) ?\[) | |
505 | (let ((end (eshell-find-delimiter ?\[ ?\]))) | |
506 | (if (not end) | |
507 | (throw 'eshell-incomplete ?\[) | |
508 | (forward-char) | |
509 | (let (eshell-glob-function) | |
510 | (setq indices (cons (eshell-parse-arguments (point) end) | |
511 | indices))) | |
512 | (goto-char (1+ end))))) | |
513 | (nreverse indices))) | |
514 | ||
515 | (defun eshell-get-variable (name &optional indices) | |
516 | "Get the value for the variable NAME." | |
517 | (let* ((alias (assoc name eshell-variable-aliases-list)) | |
518 | (var (if alias | |
519 | (cadr alias) | |
520 | name))) | |
521 | (if (and alias (functionp var)) | |
522 | (funcall var indices) | |
523 | (eshell-apply-indices | |
524 | (cond | |
525 | ((stringp var) | |
526 | (let ((sym (intern-soft var))) | |
527 | (if (and sym (boundp sym) | |
528 | (or eshell-prefer-lisp-variables | |
529 | (not (getenv var)))) | |
530 | (symbol-value sym) | |
531 | (getenv var)))) | |
532 | ((symbolp var) | |
533 | (symbol-value var)) | |
534 | (t | |
535 | (error "Unknown variable `%s'" (eshell-stringify var)))) | |
536 | indices)))) | |
537 | ||
538 | (defun eshell-apply-indices (value indices) | |
539 | "Apply to VALUE all of the given INDICES, returning the sub-result. | |
540 | The format of INDICES is: | |
541 | ||
542 | ((INT-OR-NAME-OR-OTHER INT-OR-NAME INT-OR-NAME ...) | |
543 | ...) | |
544 | ||
545 | Each member of INDICES represents a level of nesting. If the first | |
546 | member of a sublist is not an integer or name, and the value it's | |
547 | reference is a string, that will be used as the regexp with which is | |
548 | to divide the string into sub-parts. The default is whitespace. | |
549 | Otherwise, each INT-OR-NAME refers to an element of the list value. | |
550 | Integers imply a direct index, and names, an associate lookup using | |
551 | `assoc'. | |
552 | ||
553 | For example, to retrieve the second element of a user's record in | |
554 | '/etc/passwd', the variable reference would look like: | |
555 | ||
556 | ${egrep johnw /etc/passwd}[: 2]" | |
557 | (while indices | |
558 | (let ((refs (car indices))) | |
559 | (when (stringp value) | |
560 | (let (separator) | |
561 | (if (not (or (not (stringp (caar indices))) | |
562 | (string-match | |
563 | (concat "^" eshell-variable-name-regexp "$") | |
564 | (caar indices)))) | |
565 | (setq separator (caar indices) | |
566 | refs (cdr refs))) | |
567 | (setq value | |
568 | (mapcar 'eshell-convert | |
569 | (split-string value separator))))) | |
570 | (cond | |
571 | ((< (length refs) 0) | |
5b423d48 | 572 | (error "Invalid array variable index: %s" |
affbf647 GM |
573 | (eshell-stringify refs))) |
574 | ((= (length refs) 1) | |
575 | (setq value (eshell-index-value value (car refs)))) | |
576 | (t | |
577 | (let ((new-value (list t))) | |
578 | (while refs | |
579 | (nconc new-value | |
580 | (list (eshell-index-value value | |
581 | (car refs)))) | |
582 | (setq refs (cdr refs))) | |
583 | (setq value (cdr new-value)))))) | |
584 | (setq indices (cdr indices))) | |
585 | value) | |
586 | ||
587 | (defun eshell-index-value (value index) | |
588 | "Reference VALUE using the given INDEX." | |
589 | (if (stringp index) | |
590 | (cdr (assoc index value)) | |
591 | (cond | |
592 | ((ring-p value) | |
593 | (if (> index (ring-length value)) | |
594 | (error "Index exceeds length of ring") | |
595 | (ring-ref value index))) | |
596 | ((listp value) | |
597 | (if (> index (length value)) | |
598 | (error "Index exceeds length of list") | |
599 | (nth index value))) | |
600 | ((vectorp value) | |
601 | (if (> index (length value)) | |
602 | (error "Index exceeds length of vector") | |
603 | (aref value index))) | |
604 | (t | |
605 | (error "Invalid data type for indexing"))))) | |
606 | ||
607 | ;;;_* Variable name completion | |
608 | ||
609 | (defun eshell-complete-variable-reference () | |
610 | "If there is a variable reference, complete it." | |
611 | (let ((arg (pcomplete-actual-arg)) index) | |
612 | (when (setq index | |
613 | (string-match | |
614 | (concat "\\$\\(" eshell-variable-name-regexp | |
615 | "\\)?\\'") arg)) | |
616 | (setq pcomplete-stub (substring arg (1+ index))) | |
617 | (throw 'pcomplete-completions (eshell-variables-list))))) | |
618 | ||
619 | (defun eshell-variables-list () | |
620 | "Generate list of applicable variables." | |
621 | (let ((argname pcomplete-stub) | |
622 | completions) | |
623 | (eshell-for alias eshell-variable-aliases-list | |
624 | (if (string-match (concat "^" argname) (car alias)) | |
625 | (setq completions (cons (car alias) completions)))) | |
626 | (sort | |
627 | (append | |
628 | (mapcar | |
629 | (function | |
630 | (lambda (varname) | |
631 | (let ((value (eshell-get-variable varname))) | |
632 | (if (and value | |
633 | (stringp value) | |
634 | (file-directory-p value)) | |
6b0e3e4d | 635 | (concat varname "/") |
affbf647 GM |
636 | varname)))) |
637 | (eshell-envvar-names (eshell-environment-variables))) | |
638 | (all-completions argname obarray 'boundp) | |
639 | completions) | |
640 | 'string-lessp))) | |
641 | ||
642 | (defun eshell-complete-variable-assignment () | |
643 | "If there is a variable assignment, allow completion of entries." | |
644 | (let ((arg (pcomplete-actual-arg)) pos) | |
645 | (when (string-match (concat "\\`" eshell-variable-name-regexp "=") arg) | |
646 | (setq pos (match-end 0)) | |
647 | (if (string-match "\\(:\\)[^:]*\\'" arg) | |
648 | (setq pos (match-end 1))) | |
649 | (setq pcomplete-stub (substring arg pos)) | |
650 | (throw 'pcomplete-completions (pcomplete-entries))))) | |
651 | ||
652 | ;;; Code: | |
653 | ||
ab5796a9 | 654 | ;;; arch-tag: 393654fe-bdad-4f27-9a10-b1472ded14cf |
affbf647 | 655 | ;;; esh-var.el ends here |