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55535639 | 1 | ;;; env.el --- functions to manipulate environment variables |
c88ab9ce | 2 | |
0d30b337 | 3 | ;; Copyright (C) 1991, 1994, 2000, 2001, 2002, 2003, 2004, |
aaef169d | 4 | ;; 2005, 2006 Free Software Foundation, Inc. |
971571b9 | 5 | |
e5167999 | 6 | ;; Maintainer: FSF |
d9ecc911 | 7 | ;; Keywords: processes, unix |
e5167999 | 8 | |
b578f267 | 9 | ;; This file is part of GNU Emacs. |
6449c898 | 10 | |
b578f267 EN |
11 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
12 | ;; it under the terms of the GNU General Public License as published by | |
13 | ;; the Free Software Foundation; either version 2, or (at your option) | |
14 | ;; any later version. | |
6449c898 | 15 | |
b578f267 EN |
16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | ;; GNU General Public License for more details. | |
6449c898 | 20 | |
b578f267 EN |
21 | ;; You should have received a copy of the GNU General Public License |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
086add15 LK |
23 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
24 | ;; Boston, MA 02110-1301, USA. | |
6449c898 | 25 | |
d9ecc911 ER |
26 | ;;; Commentary: |
27 | ||
b578f267 EN |
28 | ;; UNIX processes inherit a list of name-to-string associations from their |
29 | ;; parents called their `environment'; these are commonly used to control | |
30 | ;; program options. This package permits you to set environment variables | |
31 | ;; to be passed to any sub-process run under Emacs. | |
d9ecc911 | 32 | |
1a90eae6 DL |
33 | ;; Note that the environment string `process-environment' is not |
34 | ;; decoded, but the args of `setenv' and `getenv' are normally | |
35 | ;; multibyte text and get coding conversion. | |
36 | ||
e5167999 ER |
37 | ;;; Code: |
38 | ||
99ac138a RS |
39 | ;; History list for environment variable names. |
40 | (defvar read-envvar-name-history nil) | |
41 | ||
42 | (defun read-envvar-name (prompt &optional mustmatch) | |
43 | "Read environment variable name, prompting with PROMPT. | |
8b740009 RS |
44 | Optional second arg MUSTMATCH, if non-nil, means require existing envvar name. |
45 | If it is also not t, RET does not exit if it does non-null completion." | |
99ac138a | 46 | (completing-read prompt |
1a90eae6 DL |
47 | (mapcar (lambda (enventry) |
48 | (list (if enable-multibyte-characters | |
49 | (decode-coding-string | |
50 | (substring enventry 0 | |
51 | (string-match "=" enventry)) | |
52 | locale-coding-system t) | |
53 | (substring enventry 0 | |
54 | (string-match "=" enventry))))) | |
99ac138a RS |
55 | process-environment) |
56 | nil mustmatch nil 'read-envvar-name-history)) | |
57 | ||
58 | ;; History list for VALUE argument to setenv. | |
59 | (defvar setenv-history nil) | |
60 | ||
a4a216c5 GM |
61 | |
62 | (defun substitute-env-vars (string) | |
63 | "Substitute environment variables referred to in STRING. | |
64 | `$FOO' where FOO is an environment variable name means to substitute | |
65 | the value of that variable. The variable name should be terminated | |
66 | with a character not a letter, digit or underscore; otherwise, enclose | |
cccc806d RS |
67 | the entire variable name in braces. For instance, in `ab$cd-x', |
68 | `$cd' is treated as an environment variable. | |
69 | ||
70 | Use `$$' to insert a single dollar sign." | |
a4a216c5 | 71 | (let ((start 0)) |
71296446 | 72 | (while (string-match |
1a90eae6 | 73 | (eval-when-compile |
cccc806d | 74 | (rx (or (and "$" (submatch (1+ (regexp "[[:alnum:]_]")))) |
1a90eae6 DL |
75 | (and "${" (submatch (minimal-match (0+ anything))) "}") |
76 | "$$"))) | |
a4a216c5 GM |
77 | string start) |
78 | (cond ((match-beginning 1) | |
79 | (let ((value (getenv (match-string 1 string)))) | |
80 | (setq string (replace-match (or value "") t t string) | |
81 | start (+ (match-beginning 0) (length value))))) | |
82 | ((match-beginning 2) | |
83 | (let ((value (getenv (match-string 2 string)))) | |
84 | (setq string (replace-match (or value "") t t string) | |
85 | start (+ (match-beginning 0) (length value))))) | |
86 | (t | |
87 | (setq string (replace-match "$" t t string) | |
88 | start (+ (match-beginning 0) 1))))) | |
89 | string)) | |
90 | ||
1a90eae6 | 91 | ;; Fixme: Should `process-environment' be recoded if LC_CTYPE &c is set? |
a4a216c5 GM |
92 | |
93 | (defun setenv (variable &optional value unset substitute-env-vars) | |
6449c898 | 94 | "Set the value of the environment variable named VARIABLE to VALUE. |
b71038b2 JB |
95 | VARIABLE should be a string. VALUE is optional; if not provided or |
96 | nil, the environment variable VARIABLE will be removed. UNSET | |
a4a216c5 GM |
97 | if non-nil means to remove VARIABLE from the environment. |
98 | SUBSTITUTE-ENV-VARS, if non-nil, means to substitute environment | |
99 | variables in VALUE with `substitute-env-vars', where see. | |
100 | Value is the new value if VARIABLE, or nil if removed from the | |
101 | environment. | |
cbfe666b RS |
102 | |
103 | Interactively, a prefix argument means to unset the variable. | |
99ac138a RS |
104 | Interactively, the current value (if any) of the variable |
105 | appears at the front of the history list when you type in the new value. | |
a4a216c5 | 106 | Interactively, always replace environment variables in the new value. |
99ac138a | 107 | |
1a90eae6 DL |
108 | This function works by modifying `process-environment'. |
109 | ||
110 | As a special case, setting variable `TZ' calls `set-time-zone-rule' as | |
111 | a side-effect." | |
cbfe666b RS |
112 | (interactive |
113 | (if current-prefix-arg | |
8b740009 | 114 | (list (read-envvar-name "Clear environment variable: " 'exact) nil t) |
2a5becfb GM |
115 | (let* ((var (read-envvar-name "Set environment variable: " nil)) |
116 | (value (getenv var))) | |
117 | (when value | |
118 | (push value setenv-history)) | |
99ac138a | 119 | ;; Here finally we specify the args to give call setenv with. |
71296446 | 120 | (list var |
a4a216c5 GM |
121 | (read-from-minibuffer (format "Set %s to value: " var) |
122 | nil nil nil 'setenv-history | |
123 | value) | |
71296446 | 124 | nil |
a4a216c5 | 125 | t)))) |
1a90eae6 | 126 | (if (and (multibyte-string-p variable) locale-coding-system) |
1ebb05c4 KH |
127 | (let ((codings (find-coding-systems-string (concat variable value)))) |
128 | (unless (or (eq 'undecided (car codings)) | |
129 | (memq (coding-system-base locale-coding-system) codings)) | |
130 | (error "Can't encode `%s=%s' with `locale-coding-system'" | |
131 | variable (or value ""))))) | |
b71038b2 | 132 | (if unset |
a4a216c5 GM |
133 | (setq value nil) |
134 | (if substitute-env-vars | |
135 | (setq value (substitute-env-vars value)))) | |
1a90eae6 DL |
136 | (if (multibyte-string-p variable) |
137 | (setq variable (encode-coding-string variable locale-coding-system))) | |
138 | (if (and value (multibyte-string-p value)) | |
139 | (setq value (encode-coding-string value locale-coding-system))) | |
6449c898 | 140 | (if (string-match "=" variable) |
1bbda2d6 | 141 | (error "Environment variable name `%s' contains `='" variable) |
971571b9 | 142 | (let ((pattern (concat "\\`" (regexp-quote (concat variable "=")))) |
7e68de56 | 143 | (case-fold-search nil) |
cbfe666b RS |
144 | (scan process-environment) |
145 | found) | |
7fd81709 RS |
146 | (if (string-equal "TZ" variable) |
147 | (set-time-zone-rule value)) | |
cbfe666b RS |
148 | (while scan |
149 | (cond ((string-match pattern (car scan)) | |
150 | (setq found t) | |
151 | (if (eq nil value) | |
1a90eae6 DL |
152 | (setq process-environment (delq (car scan) |
153 | process-environment)) | |
cbfe666b RS |
154 | (setcar scan (concat variable "=" value))) |
155 | (setq scan nil))) | |
156 | (setq scan (cdr scan))) | |
157 | (or found | |
158 | (if value | |
a3cda273 | 159 | (setq process-environment |
cbfe666b | 160 | (cons (concat variable "=" value) |
a4a216c5 GM |
161 | process-environment)))))) |
162 | value) | |
49116ac0 | 163 | |
b1e11b4f GM |
164 | (defun getenv (variable) |
165 | "Get the value of environment variable VARIABLE. | |
166 | VARIABLE should be a string. Value is nil if VARIABLE is undefined in | |
167 | the environment. Otherwise, value is a string. | |
168 | ||
169 | This function consults the variable `process-environment' | |
170 | for its value." | |
171 | (interactive (list (read-envvar-name "Get environment variable: " t))) | |
1a90eae6 DL |
172 | (let ((value (getenv-internal (if (multibyte-string-p variable) |
173 | (encode-coding-string | |
174 | variable locale-coding-system) | |
175 | variable)))) | |
176 | (if (and enable-multibyte-characters value) | |
177 | (setq value (decode-coding-string value locale-coding-system))) | |
b1e11b4f GM |
178 | (when (interactive-p) |
179 | (message "%s" (if value value "Not set"))) | |
180 | value)) | |
181 | ||
1bbda2d6 NF |
182 | (provide 'env) |
183 | ||
ab5796a9 | 184 | ;;; arch-tag: b7d6a8f7-bc81-46db-8e39-8d721d4ed0b8 |
1bbda2d6 | 185 | ;;; env.el ends here |