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Most of this change is to boilerplate commentary such as license URLs. This change was prompted by ftp://ftp.gnu.org's going-away party, planned for November. Change these FTP URLs to https://ftp.gnu.org instead. Make similar changes for URLs to other organizations moving away from FTP. Also, change HTTP to HTTPS for URLs to gnu.org and fsf.org when this works, as this will further help defend against man-in-the-middle attacks (for this part I omitted the MS-DOS and MS-Windows sources and the test tarballs to keep the workload down). HTTPS is not fully working to lists.gnu.org so I left those URLs alone for now.
224 lines
8.7 KiB
EmacsLisp
224 lines
8.7 KiB
EmacsLisp
;;; env.el --- functions to manipulate environment variables -*- lexical-binding:t -*-
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;; Copyright (C) 1991, 1994, 2000-2017 Free Software Foundation, Inc.
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;; Maintainer: emacs-devel@gnu.org
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;; Keywords: processes, unix
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;; Package: emacs
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
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;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
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;;; Commentary:
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;; UNIX processes inherit a list of name-to-string associations from their
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;; parents called their `environment'; these are commonly used to control
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;; program options. This package permits you to set environment variables
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;; to be passed to any sub-process run under Emacs.
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;; Note that the environment string `process-environment' is not
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;; decoded, but the args of `setenv' and `getenv' are normally
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;; multibyte text and get coding conversion.
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;;; Code:
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;; History list for environment variable names.
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(defvar read-envvar-name-history nil)
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(defun read-envvar-name (prompt &optional mustmatch)
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"Read environment variable name, prompting with PROMPT.
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Optional second arg MUSTMATCH, if non-nil, means require existing envvar name.
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If it is also not t, RET does not exit if it does non-null completion."
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(completing-read prompt
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(mapcar (lambda (enventry)
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(let ((str (substring enventry 0
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(string-match "=" enventry))))
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(if (multibyte-string-p str)
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(decode-coding-string
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str locale-coding-system t)
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str)))
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(append process-environment
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;;(frame-environment)
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))
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nil mustmatch nil 'read-envvar-name-history))
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;; History list for VALUE argument to setenv.
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(defvar setenv-history nil)
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(defconst env--substitute-vars-regexp
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"\\$\\(?:\\(?1:[[:alnum:]_]+\\)\\|{\\(?1:[^{}]+\\)}\\|\\$\\)")
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(defun substitute-env-vars (string &optional when-undefined)
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"Substitute environment variables referred to in STRING.
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`$FOO' where FOO is an environment variable name means to substitute
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the value of that variable. The variable name should be terminated
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with a character not a letter, digit or underscore; otherwise, enclose
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the entire variable name in braces. For instance, in `ab$cd-x',
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`$cd' is treated as an environment variable.
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If WHEN-DEFINED is nil, references to undefined environment variables
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are replaced by the empty string; if it is a function, the function is called
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with the variable name as argument and should return the text with which
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to replace it or nil to leave it unchanged.
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If it is non-nil and not a function, references to undefined variables are
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left unchanged.
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Use `$$' to insert a single dollar sign."
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(let ((start 0))
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(while (string-match env--substitute-vars-regexp string start)
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(cond ((match-beginning 1)
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(let* ((var (match-string 1 string))
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(value (getenv var)))
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(if (and (null value)
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(if (functionp when-undefined)
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(null (setq value (funcall when-undefined var)))
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when-undefined))
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(setq start (match-end 0))
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(setq string (replace-match (or value "") t t string)
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start (+ (match-beginning 0) (length value))))))
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(t
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(setq string (replace-match "$" t t string)
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start (+ (match-beginning 0) 1)))))
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string))
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(defun substitute-env-in-file-name (filename)
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(substitute-env-vars filename
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;; How 'bout we lookup other tables than the env?
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;; E.g. we could accept bookmark names as well!
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(if (memq system-type '(windows-nt ms-dos))
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(lambda (var) (getenv (upcase var)))
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t)))
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(defun setenv-internal (env variable value keep-empty)
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"Set VARIABLE to VALUE in ENV, adding empty entries if KEEP-EMPTY.
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Changes ENV by side-effect, and returns its new value."
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(let ((pattern (concat "\\`" (regexp-quote variable) "\\(=\\|\\'\\)"))
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(case-fold-search nil)
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(scan env)
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prev found)
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;; Handle deletions from the beginning of the list specially.
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(if (and (null value)
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(not keep-empty)
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env
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(stringp (car env))
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(string-match pattern (car env)))
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(cdr env)
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;; Try to find existing entry for VARIABLE in ENV.
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(while (and scan (stringp (car scan)))
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(when (string-match pattern (car scan))
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(if value
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(setcar scan (concat variable "=" value))
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(if keep-empty
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(setcar scan variable)
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(setcdr prev (cdr scan))))
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(setq found t
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scan nil))
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(setq prev scan
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scan (cdr scan)))
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(if (and (not found) (or value keep-empty))
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(cons (if value
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(concat variable "=" value)
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variable)
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env)
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env))))
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;; Fixme: Should the environment be recoded if LC_CTYPE &c is set?
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(defun setenv (variable &optional value substitute-env-vars)
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"Set the value of the environment variable named VARIABLE to VALUE.
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VARIABLE should be a string. VALUE is optional; if not provided or
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nil, the environment variable VARIABLE will be removed.
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Interactively, a prefix argument means to unset the variable, and
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otherwise the current value (if any) of the variable appears at
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the front of the history list when you type in the new value.
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This function always replaces environment variables in the new
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value when called interactively.
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SUBSTITUTE-ENV-VARS, if non-nil, means to substitute environment
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variables in VALUE with `substitute-env-vars', which see.
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This is normally used only for interactive calls.
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The return value is the new value of VARIABLE, or nil if
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it was removed from the environment.
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This function works by modifying `process-environment'.
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As a special case, setting variable `TZ' calls `set-time-zone-rule' as
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a side-effect."
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(interactive
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(if current-prefix-arg
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(list (read-envvar-name "Clear environment variable: " 'exact) nil)
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(let* ((var (read-envvar-name "Set environment variable: " nil))
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(value (getenv var)))
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(when value
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(add-to-history 'setenv-history value))
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;; Here finally we specify the args to give call setenv with.
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(list var
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(read-from-minibuffer (format "Set %s to value: " var)
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nil nil nil 'setenv-history
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value)
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t))))
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(if (and (multibyte-string-p variable) locale-coding-system)
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(let ((codings (find-coding-systems-string (concat variable value))))
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(unless (or (eq 'undecided (car codings))
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(memq (coding-system-base locale-coding-system) codings))
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(error "Can't encode `%s=%s' with `locale-coding-system'"
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variable (or value "")))))
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(and value
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substitute-env-vars
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(setq value (substitute-env-vars value)))
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(if (multibyte-string-p variable)
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(setq variable (encode-coding-string variable locale-coding-system)))
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(if (and value (multibyte-string-p value))
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(setq value (encode-coding-string value locale-coding-system)))
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(if (string-match "=" variable)
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(error "Environment variable name `%s' contains `='" variable))
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(if (string-equal "TZ" variable)
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(set-time-zone-rule value))
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(setq process-environment (setenv-internal process-environment
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variable value t))
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value)
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(defun getenv (variable &optional frame)
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"Get the value of environment variable VARIABLE.
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VARIABLE should be a string. Value is nil if VARIABLE is undefined in
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the environment. Otherwise, value is a string.
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If optional parameter FRAME is non-nil, then it should be a
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frame. This function will look up VARIABLE in its `environment'
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parameter.
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Otherwise, this function searches `process-environment' for
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VARIABLE. If it is not found there, then it continues the search
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in the environment list of the selected frame."
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(interactive (list (read-envvar-name "Get environment variable: " t)))
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(let ((value (getenv-internal (if (multibyte-string-p variable)
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(encode-coding-string
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variable locale-coding-system)
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variable)
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(and frame
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(assq 'environment
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(frame-parameters frame))))))
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(if (and enable-multibyte-characters value)
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(setq value (decode-coding-string value locale-coding-system)))
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(when (called-interactively-p 'interactive)
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(message "%s" (if value value "Not set")))
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value))
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(provide 'env)
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;;; env.el ends here
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