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60370d40 | 1 | ;;; esh-var.el --- handling of variables |
affbf647 | 2 | |
faadfb0a | 3 | ;; Copyright (C) 1999, 2000 Free Software Foundation |
affbf647 | 4 | |
7de5b421 GM |
5 | ;; Author: John Wiegley <johnw@gnu.org> |
6 | ||
affbf647 GM |
7 | ;; This file is part of GNU Emacs. |
8 | ||
9 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
10 | ;; it under the terms of the GNU General Public License as published by | |
11 | ;; the Free Software Foundation; either version 2, or (at your option) | |
12 | ;; any later version. | |
13 | ||
14 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
15 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | ;; GNU General Public License for more details. | |
18 | ||
19 | ;; You should have received a copy of the GNU General Public License | |
20 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
21 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | ;; Boston, MA 02111-1307, USA. | |
23 | ||
24 | (provide 'esh-var) | |
25 | ||
26 | (eval-when-compile (require 'esh-maint)) | |
27 | ||
28 | (defgroup eshell-var nil | |
29 | "Variable interpolation is introduced whenever the '$' character | |
30 | appears unquoted in any argument (except when that argument is | |
31 | surrounded by single quotes) . It may be used to interpolate a | |
32 | variable value, a subcommand, or even the result of a Lisp form." | |
33 | :tag "Variable handling" | |
34 | :group 'eshell) | |
35 | ||
36 | ;;; Commentary: | |
37 | ||
38 | ;; These are the possible variable interpolation syntaxes. Also keep | |
39 | ;; in mind that if an argument looks like a number, it will be | |
40 | ;; converted to a number. This is not significant when invoking | |
41 | ;; external commands, but it's important when calling Lisp functions. | |
42 | ;; | |
43 | ;; $VARIABLE | |
44 | ;; | |
45 | ;; Interval the value of an environment variable, or a Lisp variable | |
46 | ;; | |
47 | ;; $ALSO-VAR | |
48 | ;; | |
49 | ;; "-" is a legal part of a variable name. | |
50 | ;; | |
51 | ;; $<MYVAR>-TOO | |
52 | ;; | |
53 | ;; Only "MYVAR" is part of the variable name in this case. | |
54 | ;; | |
55 | ;; $#VARIABLE | |
56 | ;; | |
57 | ;; Returns the length of the value of VARIABLE. This could also be | |
58 | ;; done using the `length' Lisp function. | |
59 | ;; | |
60 | ;; $(lisp) | |
61 | ;; | |
62 | ;; Returns result of lisp evaluation. Note: Used alone like this, it | |
63 | ;; is identical to just saying (lisp); but with the variable expansion | |
64 | ;; form, the result may be interpolated a larger string, such as | |
65 | ;; '$(lisp)/other'. | |
66 | ;; | |
67 | ;; ${command} | |
68 | ;; | |
69 | ;; Returns the value of an eshell subcommand. See the note above | |
70 | ;; regarding Lisp evaluations. | |
71 | ;; | |
72 | ;; $ANYVAR[10] | |
73 | ;; | |
74 | ;; Return the 10th element of ANYVAR. If ANYVAR's value is a string, | |
75 | ;; it will be split in order to make it a list. The splitting will | |
76 | ;; occur at whitespace. | |
77 | ;; | |
78 | ;; $ANYVAR[: 10] | |
79 | ;; | |
80 | ;; As above, except that splitting occurs at the colon now. | |
81 | ;; | |
82 | ;; $ANYVAR[: 10 20] | |
83 | ;; | |
84 | ;; As above, but instead of returning just a string, it now returns a | |
85 | ;; list of two strings. If the result is being interpolated into a | |
86 | ;; larger string, this list will be flattened into one big string, | |
87 | ;; with each element separated by a space. | |
88 | ;; | |
89 | ;; $ANYVAR["\\\\" 10] | |
90 | ;; | |
91 | ;; Separate on backslash characters. Actually, the first argument -- | |
92 | ;; if it doesn't have the form of a number, or a plain variable name | |
93 | ;; -- can be any regular expression. So to split on numbers, use | |
94 | ;; '$ANYVAR["[0-9]+" 10 20]'. | |
95 | ;; | |
96 | ;; $ANYVAR[hello] | |
97 | ;; | |
98 | ;; Calls `assoc' on ANYVAR with 'hello', expecting it to be an alist. | |
99 | ;; | |
100 | ;; $#ANYVAR[hello] | |
101 | ;; | |
102 | ;; Returns the length of the cdr of the element of ANYVAR who car is | |
103 | ;; equal to "hello". | |
104 | ;; | |
105 | ;; There are also a few special variables defined by Eshell. '$$' is | |
106 | ;; the value of the last command (t or nil, in the case of an external | |
107 | ;; command). This makes it possible to chain results: | |
108 | ;; | |
109 | ;; /tmp $ echo /var/spool/mail/johnw | |
110 | ;; /var/spool/mail/johnw | |
111 | ;; /tmp $ dirname $$ | |
112 | ;; /var/spool/mail/ | |
113 | ;; /tmp $ cd $$ | |
114 | ;; /var/spool/mail $ | |
115 | ;; | |
116 | ;; '$_' refers to the last argument of the last command. And $? | |
117 | ;; contains the exit code of the last command (0 or 1 for Lisp | |
118 | ;; functions, based on successful completion). | |
119 | ||
120 | (require 'env) | |
121 | (require 'ring) | |
122 | ||
123 | ;;; User Variables: | |
124 | ||
125 | (defcustom eshell-var-load-hook '(eshell-var-initialize) | |
126 | "*A list of functions to call when loading `eshell-var'." | |
127 | :type 'hook | |
128 | :group 'eshell-var) | |
129 | ||
130 | (defcustom eshell-prefer-lisp-variables nil | |
131 | "*If non-nil, prefer Lisp variables to environment variables." | |
132 | :type 'boolean | |
133 | :group 'eshell-var) | |
134 | ||
135 | (defcustom eshell-complete-export-definition t | |
136 | "*If non-nil, completing names for `export' shows current definition." | |
137 | :type 'boolean | |
138 | :group 'eshell-var) | |
139 | ||
6995786d JW |
140 | (defcustom eshell-modify-global-environment nil |
141 | "*If non-nil, using `export' changes Emacs's global environment." | |
142 | :type 'boolean | |
143 | :group 'eshell-var) | |
144 | ||
affbf647 GM |
145 | (defcustom eshell-variable-name-regexp "[A-Za-z0-9_-]+" |
146 | "*A regexp identifying what constitutes a variable name reference. | |
147 | Note that this only applies for '$NAME'. If the syntax '$<NAME>' is | |
148 | used, then NAME can contain any character, including angle brackets, | |
149 | if they are quoted with a backslash." | |
150 | :type 'regexp | |
151 | :group 'eshell-var) | |
152 | ||
153 | (defcustom eshell-variable-aliases-list | |
154 | '(;; for eshell.el | |
155 | ("COLUMNS" (lambda (indices) (window-width)) t) | |
156 | ("LINES" (lambda (indices) (window-height)) t) | |
157 | ||
158 | ;; for eshell-cmd.el | |
159 | ("_" (lambda (indices) | |
160 | (if (not indices) | |
161 | (car (last eshell-last-arguments)) | |
162 | (eshell-apply-indices eshell-last-arguments | |
163 | indices)))) | |
164 | ("?" eshell-last-command-status) | |
165 | ("$" eshell-last-command-result) | |
166 | ("0" eshell-command-name) | |
167 | ("1" (lambda (indices) (nth 0 eshell-command-arguments))) | |
168 | ("2" (lambda (indices) (nth 1 eshell-command-arguments))) | |
169 | ("3" (lambda (indices) (nth 2 eshell-command-arguments))) | |
170 | ("4" (lambda (indices) (nth 3 eshell-command-arguments))) | |
171 | ("5" (lambda (indices) (nth 4 eshell-command-arguments))) | |
172 | ("6" (lambda (indices) (nth 5 eshell-command-arguments))) | |
173 | ("7" (lambda (indices) (nth 6 eshell-command-arguments))) | |
174 | ("8" (lambda (indices) (nth 7 eshell-command-arguments))) | |
175 | ("9" (lambda (indices) (nth 8 eshell-command-arguments))) | |
176 | ("*" (lambda (indices) | |
177 | (if (not indices) | |
178 | eshell-command-arguments | |
179 | (eshell-apply-indices eshell-command-arguments | |
180 | indices))))) | |
181 | "*This list provides aliasing for variable references. | |
182 | It is very similar in concept to what `eshell-user-aliases-list' does | |
183 | for commands. Each member of this defines defines the name of a | |
184 | command, and the Lisp value to return for that variable if it is | |
185 | accessed via the syntax '$NAME'. | |
186 | ||
187 | If the value is a function, that function will be called with two | |
188 | arguments: the list of the indices that was used in the reference, and | |
189 | whether the user is requesting the length of the ultimate element. | |
190 | For example, a reference of '$NAME[10][20]' would result in the | |
191 | function for alias `NAME' being called (assuming it were aliased to a | |
192 | function), and the arguments passed to this function would be the list | |
193 | '(10 20)', and nil." | |
194 | :type '(repeat (list string sexp | |
195 | (choice (const :tag "Copy to environment" t) | |
196 | (const :tag "Use only in Eshell" nil)))) | |
197 | :group 'eshell-var) | |
198 | ||
199 | (put 'eshell-variable-aliases-list 'risky-local-variable t) | |
200 | ||
201 | ;;; Functions: | |
202 | ||
203 | (defun eshell-var-initialize () | |
204 | "Initialize the variable handle code." | |
205 | ;; Break the association with our parent's environment. Otherwise, | |
206 | ;; changing a variable will affect all of Emacs. | |
6995786d JW |
207 | (unless eshell-modify-global-environment |
208 | (set (make-local-variable 'process-environment) | |
209 | (eshell-copy-environment))) | |
affbf647 GM |
210 | |
211 | (define-key eshell-command-map [(meta ?v)] 'eshell-insert-envvar) | |
212 | ||
213 | (set (make-local-variable 'eshell-special-chars-inside-quoting) | |
214 | (append eshell-special-chars-inside-quoting '(?$))) | |
215 | (set (make-local-variable 'eshell-special-chars-outside-quoting) | |
216 | (append eshell-special-chars-outside-quoting '(?$))) | |
217 | ||
affbf647 GM |
218 | (add-hook 'eshell-parse-argument-hook 'eshell-interpolate-variable t t) |
219 | ||
affbf647 GM |
220 | (add-hook 'eshell-prepare-command-hook |
221 | 'eshell-handle-local-variables nil t) | |
222 | ||
223 | (when (eshell-using-module 'eshell-cmpl) | |
affbf647 GM |
224 | (add-hook 'pcomplete-try-first-hook |
225 | 'eshell-complete-variable-reference nil t) | |
226 | (add-hook 'pcomplete-try-first-hook | |
227 | 'eshell-complete-variable-assignment nil t))) | |
228 | ||
229 | (defun eshell-handle-local-variables () | |
230 | "Allow for the syntax 'VAR=val <command> <args>'." | |
231 | ;; strip off any null commands, which can only happen if a variable | |
232 | ;; evaluates to nil, such as "$var x", where `var' is nil. The | |
233 | ;; command name in that case becomes `x', for compatibility with | |
234 | ;; most regular shells (the difference is that they do an | |
235 | ;; interpolation pass before the argument parsing pass, but Eshell | |
236 | ;; does both at the same time). | |
237 | (while (and (not eshell-last-command-name) | |
238 | eshell-last-arguments) | |
239 | (setq eshell-last-command-name (car eshell-last-arguments) | |
240 | eshell-last-arguments (cdr eshell-last-arguments))) | |
241 | (let ((setvar "\\`\\([A-Za-z_][A-Za-z0-9_]*\\)=\\(.*\\)\\'") | |
242 | (command (eshell-stringify eshell-last-command-name)) | |
243 | (args eshell-last-arguments)) | |
244 | ;; local variable settings (such as 'CFLAGS=-O2 make') are handled | |
245 | ;; by making the whole command into a subcommand, and calling | |
246 | ;; setenv immediately before the command is invoked. This means | |
247 | ;; that 'BLAH=x cd blah' won't work exactly as expected, but that | |
248 | ;; is by no means a typical use of local environment variables. | |
249 | (if (and command (string-match setvar command)) | |
250 | (throw | |
251 | 'eshell-replace-command | |
252 | (list | |
253 | 'eshell-as-subcommand | |
254 | (append | |
255 | (list 'progn) | |
256 | (let ((l (list t))) | |
257 | (while (string-match setvar command) | |
258 | (nconc | |
259 | l (list | |
260 | (list 'setenv (match-string 1 command) | |
261 | (match-string 2 command) | |
262 | (= (length (match-string 2 command)) 0)))) | |
263 | (setq command (eshell-stringify (car args)) | |
264 | args (cdr args))) | |
265 | (cdr l)) | |
266 | (list (list 'eshell-named-command | |
267 | command (list 'quote args))))))))) | |
268 | ||
269 | (defun eshell-interpolate-variable () | |
270 | "Parse a variable interpolation. | |
271 | This function is explicit for adding to `eshell-parse-argument-hook'." | |
272 | (when (and (eq (char-after) ?$) | |
ca7aae91 | 273 | (/= (1+ (point)) (point-max))) |
affbf647 GM |
274 | (forward-char) |
275 | (list 'eshell-escape-arg | |
276 | (eshell-parse-variable)))) | |
277 | ||
278 | (defun eshell/define (var-alias definition) | |
012d3cb5 | 279 | "Define a VAR-ALIAS using DEFINITION." |
affbf647 GM |
280 | (if (not definition) |
281 | (setq eshell-variable-aliases-list | |
282 | (delq (assoc var-alias eshell-variable-aliases-list) | |
283 | eshell-variable-aliases-list)) | |
284 | (let ((def (assoc var-alias eshell-variable-aliases-list)) | |
285 | (alias-def | |
286 | (list var-alias | |
287 | (list 'quote (if (= (length definition) 1) | |
288 | (car definition) | |
289 | definition))))) | |
290 | (if def | |
291 | (setq eshell-variable-aliases-list | |
292 | (delq (assoc var-alias eshell-variable-aliases-list) | |
293 | eshell-variable-aliases-list))) | |
294 | (setq eshell-variable-aliases-list | |
295 | (cons alias-def | |
296 | eshell-variable-aliases-list)))) | |
297 | nil) | |
298 | ||
299 | (defun eshell/export (&rest sets) | |
300 | "This alias allows the 'export' command to act as bash users expect." | |
301 | (while sets | |
ca7aae91 JW |
302 | (if (and (stringp (car sets)) |
303 | (string-match "^\\([^=]+\\)=\\(.*\\)" (car sets))) | |
affbf647 GM |
304 | (setenv (match-string 1 (car sets)) |
305 | (match-string 2 (car sets)))) | |
306 | (setq sets (cdr sets)))) | |
307 | ||
79cf8e80 JW |
308 | (defun pcomplete/eshell-mode/export () |
309 | "Completion function for Eshell's `export'." | |
310 | (while (pcomplete-here | |
311 | (if eshell-complete-export-definition | |
312 | process-environment | |
313 | (eshell-envvar-names))))) | |
314 | ||
ca7aae91 JW |
315 | (defun eshell/unset (&rest args) |
316 | "Unset an environment variable." | |
317 | (while args | |
318 | (if (stringp (car args)) | |
319 | (setenv (car args) nil t)) | |
320 | (setq args (cdr args)))) | |
321 | ||
79cf8e80 JW |
322 | (defun pcomplete/eshell-mode/unset () |
323 | "Completion function for Eshell's `unset'." | |
324 | (while (pcomplete-here (eshell-envvar-names)))) | |
affbf647 GM |
325 | |
326 | (defun eshell/setq (&rest args) | |
327 | "Allow command-ish use of `setq'." | |
328 | (let (last-value) | |
329 | (while args | |
330 | (let ((sym (intern (car args))) | |
331 | (val (cadr args))) | |
332 | (setq last-value (set sym val) | |
333 | args (cddr args)))) | |
334 | last-value)) | |
335 | ||
336 | (defun pcomplete/eshell-mode/setq () | |
337 | "Completion function for Eshell's `setq'." | |
338 | (while (and (pcomplete-here (all-completions pcomplete-stub | |
339 | obarray 'boundp)) | |
340 | (pcomplete-here)))) | |
341 | ||
342 | (defun eshell/env (&rest args) | |
343 | "Implemention of `env' in Lisp." | |
344 | (eshell-init-print-buffer) | |
345 | (eshell-eval-using-options | |
346 | "env" args | |
347 | '((?h "help" nil nil "show this usage screen") | |
348 | :external "env" | |
349 | :usage "<no arguments>") | |
350 | (eshell-for setting (sort (eshell-environment-variables) | |
351 | 'string-lessp) | |
352 | (eshell-buffered-print setting "\n")) | |
353 | (eshell-flush))) | |
354 | ||
355 | (defun eshell-insert-envvar (envvar-name) | |
356 | "Insert ENVVAR-NAME into the current buffer at point." | |
357 | (interactive | |
358 | (list (read-envvar-name "Name of environment variable: " t))) | |
359 | (insert-and-inherit "$" envvar-name)) | |
360 | ||
361 | (defun eshell-envvar-names (&optional environment) | |
362 | "Return a list of currently visible environment variable names." | |
363 | (mapcar (function | |
364 | (lambda (x) | |
365 | (substring x 0 (string-match "=" x)))) | |
366 | (or environment process-environment))) | |
367 | ||
368 | (defun eshell-environment-variables () | |
369 | "Return a `process-environment', fully updated. | |
370 | This involves setting any variable aliases which affect the | |
371 | environment, as specified in `eshell-variable-aliases-list'." | |
372 | (let ((process-environment (eshell-copy-environment))) | |
373 | (eshell-for var-alias eshell-variable-aliases-list | |
374 | (if (nth 2 var-alias) | |
375 | (setenv (car var-alias) | |
376 | (eshell-stringify | |
377 | (or (eshell-get-variable (car var-alias)) ""))))) | |
378 | process-environment)) | |
379 | ||
380 | (defun eshell-parse-variable () | |
381 | "Parse the next variable reference at point. | |
382 | The variable name could refer to either an environment variable, or a | |
383 | Lisp variable. The priority order depends on the setting of | |
384 | `eshell-prefer-lisp-variables'. | |
385 | ||
386 | Its purpose is to call `eshell-parse-variable-ref', and then to | |
387 | process any indices that come after the variable reference." | |
388 | (let* ((get-len (when (eq (char-after) ?#) | |
389 | (forward-char) t)) | |
390 | value indices) | |
391 | (setq value (eshell-parse-variable-ref) | |
392 | indices (and (not (eobp)) | |
393 | (eq (char-after) ?\[) | |
394 | (eshell-parse-indices)) | |
395 | value (list 'let | |
396 | (list (list 'indices | |
397 | (list 'quote indices))) | |
398 | value)) | |
399 | (if get-len | |
400 | (list 'length value) | |
401 | value))) | |
402 | ||
403 | (defun eshell-parse-variable-ref () | |
404 | "Eval a variable reference. | |
405 | Returns a Lisp form which, if evaluated, will return the value of the | |
406 | variable. | |
407 | ||
408 | Possible options are: | |
409 | ||
410 | NAME an environment or Lisp variable value | |
411 | <LONG-NAME> disambiguates the length of the name | |
412 | {COMMAND} result of command is variable's value | |
413 | (LISP-FORM) result of Lisp form is variable's value" | |
414 | (let (end) | |
415 | (cond | |
416 | ((eq (char-after) ?{) | |
417 | (let ((end (eshell-find-delimiter ?\{ ?\}))) | |
418 | (if (not end) | |
419 | (throw 'eshell-incomplete ?\{) | |
420 | (prog1 | |
421 | (list 'eshell-convert | |
422 | (list 'eshell-command-to-value | |
423 | (list 'eshell-as-subcommand | |
424 | (eshell-parse-command | |
425 | (cons (1+ (point)) end))))) | |
426 | (goto-char (1+ end)))))) | |
427 | ((memq (char-after) '(?\' ?\")) | |
428 | (let ((name (if (eq (char-after) ?\') | |
429 | (eshell-parse-literal-quote) | |
430 | (eshell-parse-double-quote)))) | |
431 | (if name | |
432 | (list 'eshell-get-variable (eval name) 'indices)))) | |
433 | ((eq (char-after) ?<) | |
434 | (let ((end (eshell-find-delimiter ?\< ?\>))) | |
435 | (if (not end) | |
436 | (throw 'eshell-incomplete ?\<) | |
1ae720ac | 437 | (let* ((temp (make-temp-file temporary-file-directory)) |
affbf647 GM |
438 | (cmd (concat (buffer-substring (1+ (point)) end) |
439 | " > " temp))) | |
440 | (prog1 | |
441 | (list | |
442 | 'let (list (list 'eshell-current-handles | |
443 | (list 'eshell-create-handles temp | |
444 | (list 'quote 'overwrite)))) | |
445 | (list | |
446 | 'progn | |
447 | (list 'eshell-as-subcommand | |
448 | (eshell-parse-command cmd)) | |
449 | (list 'ignore | |
450 | (list 'nconc 'eshell-this-command-hook | |
451 | (list 'list | |
452 | (list 'function | |
453 | (list 'lambda nil | |
454 | (list 'delete-file temp)))))) | |
455 | (list 'quote temp))) | |
456 | (goto-char (1+ end))))))) | |
457 | ((eq (char-after) ?\() | |
458 | (condition-case err | |
459 | (list 'eshell-command-to-value | |
460 | (list 'eshell-lisp-command | |
461 | (list 'quote (read (current-buffer))))) | |
462 | (end-of-file | |
463 | (throw 'eshell-incomplete ?\()))) | |
464 | ((assoc (char-to-string (char-after)) | |
465 | eshell-variable-aliases-list) | |
466 | (forward-char) | |
467 | (list 'eshell-get-variable | |
468 | (char-to-string (char-before)) 'indices)) | |
469 | ((looking-at eshell-variable-name-regexp) | |
470 | (prog1 | |
471 | (list 'eshell-get-variable (match-string 0) 'indices) | |
472 | (goto-char (match-end 0)))) | |
473 | (t | |
474 | (error "Invalid variable reference"))))) | |
475 | ||
476 | (eshell-deftest var interp-cmd | |
477 | "Interpolate command result" | |
478 | (eshell-command-result-p "+ ${+ 1 2} 3" "6\n")) | |
479 | ||
480 | (eshell-deftest var interp-lisp | |
481 | "Interpolate Lisp form evalution" | |
482 | (eshell-command-result-p "+ $(+ 1 2) 3" "6\n")) | |
483 | ||
484 | (eshell-deftest var interp-concat | |
485 | "Interpolate and concat command" | |
486 | (eshell-command-result-p "+ ${+ 1 2}3 3" "36\n")) | |
487 | ||
488 | (eshell-deftest var interp-concat-lisp | |
489 | "Interpolate and concat Lisp form" | |
490 | (eshell-command-result-p "+ $(+ 1 2)3 3" "36\n")) | |
491 | ||
492 | (eshell-deftest var interp-concat2 | |
493 | "Interpolate and concat two commands" | |
494 | (eshell-command-result-p "+ ${+ 1 2}${+ 1 2} 3" "36\n")) | |
495 | ||
496 | (eshell-deftest var interp-concat-lisp2 | |
497 | "Interpolate and concat two Lisp forms" | |
498 | (eshell-command-result-p "+ $(+ 1 2)$(+ 1 2) 3" "36\n")) | |
499 | ||
500 | (defun eshell-parse-indices () | |
501 | "Parse and return a list of list of indices." | |
502 | (let (indices) | |
503 | (while (eq (char-after) ?\[) | |
504 | (let ((end (eshell-find-delimiter ?\[ ?\]))) | |
505 | (if (not end) | |
506 | (throw 'eshell-incomplete ?\[) | |
507 | (forward-char) | |
508 | (let (eshell-glob-function) | |
509 | (setq indices (cons (eshell-parse-arguments (point) end) | |
510 | indices))) | |
511 | (goto-char (1+ end))))) | |
512 | (nreverse indices))) | |
513 | ||
514 | (defun eshell-get-variable (name &optional indices) | |
515 | "Get the value for the variable NAME." | |
516 | (let* ((alias (assoc name eshell-variable-aliases-list)) | |
517 | (var (if alias | |
518 | (cadr alias) | |
519 | name))) | |
520 | (if (and alias (functionp var)) | |
521 | (funcall var indices) | |
522 | (eshell-apply-indices | |
523 | (cond | |
524 | ((stringp var) | |
525 | (let ((sym (intern-soft var))) | |
526 | (if (and sym (boundp sym) | |
527 | (or eshell-prefer-lisp-variables | |
528 | (not (getenv var)))) | |
529 | (symbol-value sym) | |
530 | (getenv var)))) | |
531 | ((symbolp var) | |
532 | (symbol-value var)) | |
533 | (t | |
534 | (error "Unknown variable `%s'" (eshell-stringify var)))) | |
535 | indices)))) | |
536 | ||
537 | (defun eshell-apply-indices (value indices) | |
538 | "Apply to VALUE all of the given INDICES, returning the sub-result. | |
539 | The format of INDICES is: | |
540 | ||
541 | ((INT-OR-NAME-OR-OTHER INT-OR-NAME INT-OR-NAME ...) | |
542 | ...) | |
543 | ||
544 | Each member of INDICES represents a level of nesting. If the first | |
545 | member of a sublist is not an integer or name, and the value it's | |
546 | reference is a string, that will be used as the regexp with which is | |
547 | to divide the string into sub-parts. The default is whitespace. | |
548 | Otherwise, each INT-OR-NAME refers to an element of the list value. | |
549 | Integers imply a direct index, and names, an associate lookup using | |
550 | `assoc'. | |
551 | ||
552 | For example, to retrieve the second element of a user's record in | |
553 | '/etc/passwd', the variable reference would look like: | |
554 | ||
555 | ${egrep johnw /etc/passwd}[: 2]" | |
556 | (while indices | |
557 | (let ((refs (car indices))) | |
558 | (when (stringp value) | |
559 | (let (separator) | |
560 | (if (not (or (not (stringp (caar indices))) | |
561 | (string-match | |
562 | (concat "^" eshell-variable-name-regexp "$") | |
563 | (caar indices)))) | |
564 | (setq separator (caar indices) | |
565 | refs (cdr refs))) | |
566 | (setq value | |
567 | (mapcar 'eshell-convert | |
568 | (split-string value separator))))) | |
569 | (cond | |
570 | ((< (length refs) 0) | |
571 | (error "Illegal array variable index: %s" | |
572 | (eshell-stringify refs))) | |
573 | ((= (length refs) 1) | |
574 | (setq value (eshell-index-value value (car refs)))) | |
575 | (t | |
576 | (let ((new-value (list t))) | |
577 | (while refs | |
578 | (nconc new-value | |
579 | (list (eshell-index-value value | |
580 | (car refs)))) | |
581 | (setq refs (cdr refs))) | |
582 | (setq value (cdr new-value)))))) | |
583 | (setq indices (cdr indices))) | |
584 | value) | |
585 | ||
586 | (defun eshell-index-value (value index) | |
587 | "Reference VALUE using the given INDEX." | |
588 | (if (stringp index) | |
589 | (cdr (assoc index value)) | |
590 | (cond | |
591 | ((ring-p value) | |
592 | (if (> index (ring-length value)) | |
593 | (error "Index exceeds length of ring") | |
594 | (ring-ref value index))) | |
595 | ((listp value) | |
596 | (if (> index (length value)) | |
597 | (error "Index exceeds length of list") | |
598 | (nth index value))) | |
599 | ((vectorp value) | |
600 | (if (> index (length value)) | |
601 | (error "Index exceeds length of vector") | |
602 | (aref value index))) | |
603 | (t | |
604 | (error "Invalid data type for indexing"))))) | |
605 | ||
606 | ;;;_* Variable name completion | |
607 | ||
608 | (defun eshell-complete-variable-reference () | |
609 | "If there is a variable reference, complete it." | |
610 | (let ((arg (pcomplete-actual-arg)) index) | |
611 | (when (setq index | |
612 | (string-match | |
613 | (concat "\\$\\(" eshell-variable-name-regexp | |
614 | "\\)?\\'") arg)) | |
615 | (setq pcomplete-stub (substring arg (1+ index))) | |
616 | (throw 'pcomplete-completions (eshell-variables-list))))) | |
617 | ||
618 | (defun eshell-variables-list () | |
619 | "Generate list of applicable variables." | |
620 | (let ((argname pcomplete-stub) | |
621 | completions) | |
622 | (eshell-for alias eshell-variable-aliases-list | |
623 | (if (string-match (concat "^" argname) (car alias)) | |
624 | (setq completions (cons (car alias) completions)))) | |
625 | (sort | |
626 | (append | |
627 | (mapcar | |
628 | (function | |
629 | (lambda (varname) | |
630 | (let ((value (eshell-get-variable varname))) | |
631 | (if (and value | |
632 | (stringp value) | |
633 | (file-directory-p value)) | |
634 | (concat varname (char-to-string directory-sep-char)) | |
635 | varname)))) | |
636 | (eshell-envvar-names (eshell-environment-variables))) | |
637 | (all-completions argname obarray 'boundp) | |
638 | completions) | |
639 | 'string-lessp))) | |
640 | ||
641 | (defun eshell-complete-variable-assignment () | |
642 | "If there is a variable assignment, allow completion of entries." | |
643 | (let ((arg (pcomplete-actual-arg)) pos) | |
644 | (when (string-match (concat "\\`" eshell-variable-name-regexp "=") arg) | |
645 | (setq pos (match-end 0)) | |
646 | (if (string-match "\\(:\\)[^:]*\\'" arg) | |
647 | (setq pos (match-end 1))) | |
648 | (setq pcomplete-stub (substring arg pos)) | |
649 | (throw 'pcomplete-completions (pcomplete-entries))))) | |
650 | ||
651 | ;;; Code: | |
652 | ||
ab5796a9 | 653 | ;;; arch-tag: 393654fe-bdad-4f27-9a10-b1472ded14cf |
affbf647 | 654 | ;;; esh-var.el ends here |