-;;; env.el --- functions to manipulate environment variables.
+;;; env.el --- functions to manipulate environment variables
-;;; Copyright 1991, 1994 Free Software Foundation, Inc.
+;; Copyright (C) 1991, 1994, 2000, 2001, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: processes, unix
-;;; This file is part of GNU Emacs.
+;; This file is part of GNU Emacs.
-;;; GNU Emacs is free software; you can redistribute it and/or modify
-;;; it under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation; either version 2, or (at your option)
-;;; any later version.
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
-;;; GNU Emacs is distributed in the hope that it will be useful,
-;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;;; GNU General Public License for more details.
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
-;;; You should have received a copy of the GNU General Public License
-;;; along with GNU Emacs; see the file COPYING. If not, write to
-;;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
-;; UNIX processes inherit a list of name-to-string associations from
-;; their parents called their `environment'; these are commonly used
-;; to control program options. This package permits you to set
-;; environment variables to be passed to any sub-process run under Emacs.
+;; UNIX processes inherit a list of name-to-string associations from their
+;; parents called their `environment'; these are commonly used to control
+;; program options. This package permits you to set environment variables
+;; to be passed to any sub-process run under Emacs.
+
+;; Note that the environment string `process-environment' is not
+;; decoded, but the args of `setenv' and `getenv' are normally
+;; multibyte text and get coding conversion.
;;; Code:
-;;;###autoload
-(defun setenv (variable &optional value unset)
+;; History list for environment variable names.
+(defvar read-envvar-name-history nil)
+
+(defun read-envvar-name (prompt &optional mustmatch)
+ "Read environment variable name, prompting with PROMPT.
+Optional second arg MUSTMATCH, if non-nil, means require existing envvar name.
+If it is also not t, RET does not exit if it does non-null completion."
+ (completing-read prompt
+ (mapcar (lambda (enventry)
+ (list (if enable-multibyte-characters
+ (decode-coding-string
+ (substring enventry 0
+ (string-match "=" enventry))
+ locale-coding-system t)
+ (substring enventry 0
+ (string-match "=" enventry)))))
+ process-environment)
+ nil mustmatch nil 'read-envvar-name-history))
+
+;; History list for VALUE argument to setenv.
+(defvar setenv-history nil)
+
+
+(defun substitute-env-vars (string)
+ "Substitute environment variables referred to in STRING.
+`$FOO' where FOO is an environment variable name means to substitute
+the value of that variable. The variable name should be terminated
+with a character not a letter, digit or underscore; otherwise, enclose
+the entire variable name in braces. For instance, in `ab$cd-x',
+`$cd' is treated as an environment variable.
+
+Use `$$' to insert a single dollar sign."
+ (let ((start 0))
+ (while (string-match
+ (eval-when-compile
+ (rx (or (and "$" (submatch (1+ (regexp "[[:alnum:]_]"))))
+ (and "${" (submatch (minimal-match (0+ anything))) "}")
+ "$$")))
+ string start)
+ (cond ((match-beginning 1)
+ (let ((value (getenv (match-string 1 string))))
+ (setq string (replace-match (or value "") t t string)
+ start (+ (match-beginning 0) (length value)))))
+ ((match-beginning 2)
+ (let ((value (getenv (match-string 2 string))))
+ (setq string (replace-match (or value "") t t string)
+ start (+ (match-beginning 0) (length value)))))
+ (t
+ (setq string (replace-match "$" t t string)
+ start (+ (match-beginning 0) 1)))))
+ string))
+
+;; Fixme: Should `process-environment' be recoded if LC_CTYPE &c is set?
+
+(defun setenv (variable &optional value substitute-env-vars)
"Set the value of the environment variable named VARIABLE to VALUE.
-VARIABLE should be a string. VALUE is optional; if not provided or is
-`nil', the environment variable VARIABLE will be removed.
+VARIABLE should be a string. VALUE is optional; if not provided or
+nil, the environment variable VARIABLE will be removed.
Interactively, a prefix argument means to unset the variable.
-This function works by modifying `process-environment'."
+Interactively, the current value (if any) of the variable
+appears at the front of the history list when you type in the new value.
+Interactively, always replace environment variables in the new value.
+
+SUBSTITUTE-ENV-VARS, if non-nil, means to substitute environment
+variables in VALUE with `substitute-env-vars', which see.
+This is normally used only for interactive calls.
+
+The return value is the new value of VARIABLE, or nil if
+it was removed from the environment.
+
+This function works by modifying `process-environment'.
+
+As a special case, setting variable `TZ' calls `set-time-zone-rule' as
+a side-effect."
(interactive
(if current-prefix-arg
- (list (read-string "Clear environment variable: ") nil t)
- (let ((var (read-string "Set environment variable: ")))
- (list var (read-string (format "Set %s to value: " var))))))
- (if unset (setq value nil))
+ (list (read-envvar-name "Clear environment variable: " 'exact) nil)
+ (let* ((var (read-envvar-name "Set environment variable: " nil))
+ (value (getenv var)))
+ (when value
+ (push value setenv-history))
+ ;; Here finally we specify the args to give call setenv with.
+ (list var
+ (read-from-minibuffer (format "Set %s to value: " var)
+ nil nil nil 'setenv-history
+ value)
+ t))))
+ (if (and (multibyte-string-p variable) locale-coding-system)
+ (let ((codings (find-coding-systems-string (concat variable value))))
+ (unless (or (eq 'undecided (car codings))
+ (memq (coding-system-base locale-coding-system) codings))
+ (error "Can't encode `%s=%s' with `locale-coding-system'"
+ variable (or value "")))))
+ (and value
+ substitute-env-vars
+ (setq value (substitute-env-vars value)))
+ (if (multibyte-string-p variable)
+ (setq variable (encode-coding-string variable locale-coding-system)))
+ (if (and value (multibyte-string-p value))
+ (setq value (encode-coding-string value locale-coding-system)))
(if (string-match "=" variable)
(error "Environment variable name `%s' contains `='" variable)
(let ((pattern (concat "\\`" (regexp-quote (concat variable "="))))
(case-fold-search nil)
(scan process-environment)
found)
+ (if (string-equal "TZ" variable)
+ (set-time-zone-rule value))
(while scan
(cond ((string-match pattern (car scan))
(setq found t)
(if (eq nil value)
- (setq process-environment (delq (car scan) process-environment))
+ (setq process-environment (delq (car scan)
+ process-environment))
(setcar scan (concat variable "=" value)))
(setq scan nil)))
(setq scan (cdr scan)))
(if value
(setq process-environment
(cons (concat variable "=" value)
- process-environment)))))))
+ process-environment))))))
+ value)
+
+(defun getenv (variable)
+ "Get the value of environment variable VARIABLE.
+VARIABLE should be a string. Value is nil if VARIABLE is undefined in
+the environment. Otherwise, value is a string.
+
+This function consults the variable `process-environment'
+for its value."
+ (interactive (list (read-envvar-name "Get environment variable: " t)))
+ (let ((value (getenv-internal (if (multibyte-string-p variable)
+ (encode-coding-string
+ variable locale-coding-system)
+ variable))))
+ (if (and enable-multibyte-characters value)
+ (setq value (decode-coding-string value locale-coding-system)))
+ (when (interactive-p)
+ (message "%s" (if value value "Not set")))
+ value))
(provide 'env)
+;;; arch-tag: b7d6a8f7-bc81-46db-8e39-8d721d4ed0b8
;;; env.el ends here