246 lines
9.6 KiB
EmacsLisp
246 lines
9.6 KiB
EmacsLisp
;;; env.el --- functions to manipulate environment variables -*- lexical-binding:t -*-
|
|
|
|
;; Copyright (C) 1991-2024 Free Software Foundation, Inc.
|
|
|
|
;; Maintainer: emacs-devel@gnu.org
|
|
;; Keywords: processes, unix
|
|
;; Package: 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 3 of the License, 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.
|
|
|
|
;; You should have received a copy of the GNU General Public License
|
|
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
;;; 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.
|
|
|
|
;; 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:
|
|
|
|
;; 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)
|
|
(let ((str (substring enventry 0
|
|
(string-search "=" enventry))))
|
|
(if (multibyte-string-p str)
|
|
(decode-coding-string
|
|
str locale-coding-system t)
|
|
str)))
|
|
(append process-environment
|
|
;;(frame-environment)
|
|
))
|
|
nil mustmatch nil 'read-envvar-name-history))
|
|
|
|
;; History list for VALUE argument to setenv.
|
|
(defvar setenv-history nil)
|
|
|
|
(defconst env--substitute-vars-regexp
|
|
"\\$\\(?:\\(?1:[[:alnum:]_]+\\)\\|{\\(?1:[^{}]+\\)}\\|\\$\\)")
|
|
|
|
(defun substitute-env-vars (string &optional when-undefined)
|
|
"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.
|
|
|
|
If WHEN-UNDEFINED is omitted or nil, references to undefined environment
|
|
variables are replaced by the empty string; if it is a function, the
|
|
function is called with the variable's name as argument, and should return
|
|
the text with which to replace it, or nil to leave it unchanged.
|
|
If it is non-nil and not a function, references to undefined variables are
|
|
left unchanged.
|
|
|
|
Use `$$' to insert a single dollar sign."
|
|
(declare (important-return-value t))
|
|
(let ((start 0))
|
|
(while (string-match env--substitute-vars-regexp string start)
|
|
(cond ((match-beginning 1)
|
|
(let* ((var (match-string 1 string))
|
|
(value (getenv var)))
|
|
(if (and (null value)
|
|
(if (functionp when-undefined)
|
|
(null (setq value (funcall when-undefined var)))
|
|
when-undefined))
|
|
(setq start (match-end 0))
|
|
(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))
|
|
|
|
(defun substitute-env-in-file-name (filename)
|
|
(declare (important-return-value t))
|
|
(substitute-env-vars filename
|
|
;; How 'bout we lookup other tables than the env?
|
|
;; E.g. we could accept bookmark names as well!
|
|
(if (memq system-type '(windows-nt ms-dos))
|
|
(lambda (var) (getenv (upcase var)))
|
|
t)))
|
|
|
|
(defun setenv-internal (env variable value keep-empty)
|
|
"Set VARIABLE to VALUE in ENV, adding empty entries if KEEP-EMPTY.
|
|
Changes ENV by side-effect, and returns its new value."
|
|
(declare (important-return-value t))
|
|
(let ((pattern (concat "\\`" (regexp-quote variable) "\\(=\\|\\'\\)"))
|
|
(case-fold-search nil)
|
|
(scan env)
|
|
prev found)
|
|
;; Handle deletions from the beginning of the list specially.
|
|
(if (and (null value)
|
|
(not keep-empty)
|
|
env
|
|
(stringp (car env))
|
|
(string-match-p pattern (car env)))
|
|
(cdr env)
|
|
;; Try to find existing entry for VARIABLE in ENV.
|
|
(while (and scan (stringp (car scan)))
|
|
(when (string-match-p pattern (car scan))
|
|
(if value
|
|
(setcar scan (concat variable "=" value))
|
|
(if keep-empty
|
|
(setcar scan variable)
|
|
(setcdr prev (cdr scan))))
|
|
(setq found t
|
|
scan nil))
|
|
(setq prev scan
|
|
scan (cdr scan)))
|
|
(if (and (not found) (or value keep-empty))
|
|
(cons (if value
|
|
(concat variable "=" value)
|
|
variable)
|
|
env)
|
|
env))))
|
|
|
|
;; Fixme: Should the 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
|
|
nil, the environment variable VARIABLE will be removed.
|
|
|
|
Interactively, a prefix argument means to unset the variable, and
|
|
otherwise the current value (if any) of the variable appears at
|
|
the front of the history list when you type in the new value.
|
|
This function always replaces environment variables in the new
|
|
value when called interactively.
|
|
|
|
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-envvar-name "Clear environment variable: " 'exact) nil)
|
|
(let* ((var (read-envvar-name "Set environment variable: " nil))
|
|
(value (getenv var)))
|
|
(when value
|
|
(add-to-history 'setenv-history value))
|
|
;; 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-search "=" variable)
|
|
(error "Environment variable name `%s' contains `='" variable))
|
|
(if (string-equal "TZ" variable)
|
|
(set-time-zone-rule value))
|
|
(setq process-environment (setenv-internal process-environment
|
|
variable value t))
|
|
value)
|
|
|
|
(defun getenv (variable &optional frame)
|
|
"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.
|
|
|
|
If optional parameter FRAME is non-nil, then it should be a
|
|
frame. This function will look up VARIABLE in its `environment'
|
|
parameter.
|
|
|
|
Otherwise, this function searches `process-environment' for
|
|
VARIABLE. If it is not found there, then it continues the search
|
|
in the environment list of the selected frame."
|
|
(declare (ftype (function (string &optional frame) (or null string)))
|
|
(side-effect-free t))
|
|
(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)
|
|
(and frame
|
|
(assq 'environment
|
|
(frame-parameters frame))))))
|
|
(if (and enable-multibyte-characters value)
|
|
(setq value (decode-coding-string value locale-coding-system)))
|
|
(when (called-interactively-p 'interactive)
|
|
(message "%s" (if value value "Not set")))
|
|
value))
|
|
|
|
;;;###autoload
|
|
(defmacro with-environment-variables (variables &rest body)
|
|
"Set VARIABLES in the environment and execute BODY.
|
|
VARIABLES is a list of variable settings of the form (VAR VALUE),
|
|
where VAR is the name of the variable (a string) and VALUE
|
|
is its value (also a string).
|
|
|
|
The previous values will be restored upon exit."
|
|
(declare (indent 1) (debug (sexp body)))
|
|
(unless (consp variables)
|
|
(error "Invalid VARIABLES: %s" variables))
|
|
`(let ((process-environment (copy-sequence process-environment)))
|
|
,@(mapcar (lambda (elem)
|
|
`(setenv ,(car elem) ,(cadr elem)))
|
|
variables)
|
|
,@body))
|
|
|
|
(provide 'env)
|
|
|
|
;;; env.el ends here
|