Commit | Line | Data |
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55535639 | 1 | ;;; env.el --- functions to manipulate environment variables |
c88ab9ce | 2 | |
1a90eae6 | 3 | ;; Copyright (C) 1991, 1994, 2000, 2001, 2003 Free Software Foundation, Inc. |
971571b9 | 4 | |
e5167999 | 5 | ;; Maintainer: FSF |
d9ecc911 | 6 | ;; Keywords: processes, unix |
e5167999 | 7 | |
b578f267 | 8 | ;; This file is part of GNU Emacs. |
6449c898 | 9 | |
b578f267 EN |
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. | |
6449c898 | 14 | |
b578f267 EN |
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. | |
6449c898 | 19 | |
b578f267 EN |
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 | |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
6449c898 | 24 | |
d9ecc911 ER |
25 | ;;; Commentary: |
26 | ||
b578f267 EN |
27 | ;; UNIX processes inherit a list of name-to-string associations from their |
28 | ;; parents called their `environment'; these are commonly used to control | |
29 | ;; program options. This package permits you to set environment variables | |
30 | ;; to be passed to any sub-process run under Emacs. | |
d9ecc911 | 31 | |
1a90eae6 DL |
32 | ;; Note that the environment string `process-environment' is not |
33 | ;; decoded, but the args of `setenv' and `getenv' are normally | |
34 | ;; multibyte text and get coding conversion. | |
35 | ||
e5167999 ER |
36 | ;;; Code: |
37 | ||
99ac138a RS |
38 | ;; History list for environment variable names. |
39 | (defvar read-envvar-name-history nil) | |
40 | ||
41 | (defun read-envvar-name (prompt &optional mustmatch) | |
42 | "Read environment variable name, prompting with PROMPT. | |
8b740009 RS |
43 | Optional second arg MUSTMATCH, if non-nil, means require existing envvar name. |
44 | If it is also not t, RET does not exit if it does non-null completion." | |
99ac138a | 45 | (completing-read prompt |
1a90eae6 DL |
46 | (mapcar (lambda (enventry) |
47 | (list (if enable-multibyte-characters | |
48 | (decode-coding-string | |
49 | (substring enventry 0 | |
50 | (string-match "=" enventry)) | |
51 | locale-coding-system t) | |
52 | (substring enventry 0 | |
53 | (string-match "=" enventry))))) | |
99ac138a RS |
54 | process-environment) |
55 | nil mustmatch nil 'read-envvar-name-history)) | |
56 | ||
57 | ;; History list for VALUE argument to setenv. | |
58 | (defvar setenv-history nil) | |
59 | ||
a4a216c5 GM |
60 | |
61 | (defun substitute-env-vars (string) | |
62 | "Substitute environment variables referred to in STRING. | |
63 | `$FOO' where FOO is an environment variable name means to substitute | |
64 | the value of that variable. The variable name should be terminated | |
65 | with a character not a letter, digit or underscore; otherwise, enclose | |
71296446 | 66 | the entire variable name in braces. Use `$$' to insert a single |
a4a216c5 GM |
67 | dollar sign." |
68 | (let ((start 0)) | |
71296446 | 69 | (while (string-match |
1a90eae6 DL |
70 | (eval-when-compile |
71 | (rx (or (and "$" (submatch (1+ (regexp "[:alnum:]_")))) | |
72 | (and "${" (submatch (minimal-match (0+ anything))) "}") | |
73 | "$$"))) | |
a4a216c5 GM |
74 | string start) |
75 | (cond ((match-beginning 1) | |
76 | (let ((value (getenv (match-string 1 string)))) | |
77 | (setq string (replace-match (or value "") t t string) | |
78 | start (+ (match-beginning 0) (length value))))) | |
79 | ((match-beginning 2) | |
80 | (let ((value (getenv (match-string 2 string)))) | |
81 | (setq string (replace-match (or value "") t t string) | |
82 | start (+ (match-beginning 0) (length value))))) | |
83 | (t | |
84 | (setq string (replace-match "$" t t string) | |
85 | start (+ (match-beginning 0) 1))))) | |
86 | string)) | |
87 | ||
1a90eae6 | 88 | ;; Fixme: Should `process-environment' be recoded if LC_CTYPE &c is set? |
a4a216c5 GM |
89 | |
90 | (defun setenv (variable &optional value unset substitute-env-vars) | |
6449c898 | 91 | "Set the value of the environment variable named VARIABLE to VALUE. |
1bbda2d6 | 92 | VARIABLE should be a string. VALUE is optional; if not provided or is |
a4a216c5 GM |
93 | `nil', the environment variable VARIABLE will be removed. UNSET |
94 | if non-nil means to remove VARIABLE from the environment. | |
95 | SUBSTITUTE-ENV-VARS, if non-nil, means to substitute environment | |
96 | variables in VALUE with `substitute-env-vars', where see. | |
97 | Value is the new value if VARIABLE, or nil if removed from the | |
98 | environment. | |
cbfe666b RS |
99 | |
100 | Interactively, a prefix argument means to unset the variable. | |
99ac138a RS |
101 | Interactively, the current value (if any) of the variable |
102 | appears at the front of the history list when you type in the new value. | |
a4a216c5 | 103 | Interactively, always replace environment variables in the new value. |
99ac138a | 104 | |
1a90eae6 DL |
105 | This function works by modifying `process-environment'. |
106 | ||
107 | As a special case, setting variable `TZ' calls `set-time-zone-rule' as | |
108 | a side-effect." | |
cbfe666b RS |
109 | (interactive |
110 | (if current-prefix-arg | |
8b740009 | 111 | (list (read-envvar-name "Clear environment variable: " 'exact) nil t) |
2a5becfb GM |
112 | (let* ((var (read-envvar-name "Set environment variable: " nil)) |
113 | (value (getenv var))) | |
114 | (when value | |
115 | (push value setenv-history)) | |
99ac138a | 116 | ;; Here finally we specify the args to give call setenv with. |
71296446 | 117 | (list var |
a4a216c5 GM |
118 | (read-from-minibuffer (format "Set %s to value: " var) |
119 | nil nil nil 'setenv-history | |
120 | value) | |
71296446 | 121 | nil |
a4a216c5 | 122 | t)))) |
1a90eae6 | 123 | (if (and (multibyte-string-p variable) locale-coding-system) |
1ebb05c4 KH |
124 | (let ((codings (find-coding-systems-string (concat variable value)))) |
125 | (unless (or (eq 'undecided (car codings)) | |
126 | (memq (coding-system-base locale-coding-system) codings)) | |
127 | (error "Can't encode `%s=%s' with `locale-coding-system'" | |
128 | variable (or value ""))))) | |
1a90eae6 | 129 | (if unset |
a4a216c5 GM |
130 | (setq value nil) |
131 | (if substitute-env-vars | |
132 | (setq value (substitute-env-vars value)))) | |
1a90eae6 DL |
133 | (if (multibyte-string-p variable) |
134 | (setq variable (encode-coding-string variable locale-coding-system))) | |
135 | (if (and value (multibyte-string-p value)) | |
136 | (setq value (encode-coding-string value locale-coding-system))) | |
6449c898 | 137 | (if (string-match "=" variable) |
1bbda2d6 | 138 | (error "Environment variable name `%s' contains `='" variable) |
971571b9 | 139 | (let ((pattern (concat "\\`" (regexp-quote (concat variable "=")))) |
7e68de56 | 140 | (case-fold-search nil) |
cbfe666b RS |
141 | (scan process-environment) |
142 | found) | |
7fd81709 RS |
143 | (if (string-equal "TZ" variable) |
144 | (set-time-zone-rule value)) | |
cbfe666b RS |
145 | (while scan |
146 | (cond ((string-match pattern (car scan)) | |
147 | (setq found t) | |
148 | (if (eq nil value) | |
1a90eae6 DL |
149 | (setq process-environment (delq (car scan) |
150 | process-environment)) | |
cbfe666b RS |
151 | (setcar scan (concat variable "=" value))) |
152 | (setq scan nil))) | |
153 | (setq scan (cdr scan))) | |
154 | (or found | |
155 | (if value | |
a3cda273 | 156 | (setq process-environment |
cbfe666b | 157 | (cons (concat variable "=" value) |
a4a216c5 GM |
158 | process-environment)))))) |
159 | value) | |
49116ac0 | 160 | |
b1e11b4f GM |
161 | (defun getenv (variable) |
162 | "Get the value of environment variable VARIABLE. | |
163 | VARIABLE should be a string. Value is nil if VARIABLE is undefined in | |
164 | the environment. Otherwise, value is a string. | |
165 | ||
166 | This function consults the variable `process-environment' | |
167 | for its value." | |
168 | (interactive (list (read-envvar-name "Get environment variable: " t))) | |
1a90eae6 DL |
169 | (let ((value (getenv-internal (if (multibyte-string-p variable) |
170 | (encode-coding-string | |
171 | variable locale-coding-system) | |
172 | variable)))) | |
173 | (if (and enable-multibyte-characters value) | |
174 | (setq value (decode-coding-string value locale-coding-system))) | |
b1e11b4f GM |
175 | (when (interactive-p) |
176 | (message "%s" (if value value "Not set"))) | |
177 | value)) | |
178 | ||
1bbda2d6 NF |
179 | (provide 'env) |
180 | ||
181 | ;;; env.el ends here |