-;;; env.el --- functions to manipulate environment variables
+;;; env.el --- functions to manipulate environment variables -*- lexical-binding:t -*-
-;; Copyright (C) 1991, 1994, 2000, 2001, 2002, 2003, 2004,
-;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+;; Copyright (C) 1991, 1994, 2000-2016 Free Software Foundation, Inc.
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
;; Keywords: processes, unix
+;; Package: emacs
;; This file is part of GNU Emacs.
;;; Code:
-(eval-when-compile (require 'cl))
-
;; History list for environment variable names.
(defvar read-envvar-name-history nil)
;; History list for VALUE argument to setenv.
(defvar setenv-history nil)
+(defconst env--substitute-vars-regexp
+ "\\$\\(?:\\(?1:[[:alnum:]_]+\\)\\|{\\(?1:[^{}]+\\)}\\|\\$\\)")
-(defun substitute-env-vars (string)
+(defun substitute-env-vars (string &optional when-undefined)
"Substitute environment variables referred to in STRING.
`$FOO' where FOO is an environment variable name means to substitute
the value of that variable. The variable name should be terminated
the entire variable name in braces. For instance, in `ab$cd-x',
`$cd' is treated as an environment variable.
+If WHEN-DEFINED is nil, references to undefined environment variables
+are replaced by the empty string; if it is a function, the function is called
+with the variable 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 `$$' to insert a single dollar sign."
(let ((start 0))
- (while (string-match
- (eval-when-compile
- (rx (or (and "$" (submatch (1+ (regexp "[[:alnum:]_]"))))
- (and "${" (submatch (minimal-match (0+ anything))) "}")
- "$$")))
- string start)
+ (while (string-match env--substitute-vars-regexp 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)))))
+ (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)
+ (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.
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
+frame. This function will look up VARIABLE in its `environment'
parameter.
Otherwise, this function searches `process-environment' for
(encode-coding-string
variable locale-coding-system)
variable)
- frame)))
+ (and frame
+ (assq 'environment
+ (frame-parameters frame))))))
(if (and enable-multibyte-characters value)
(setq value (decode-coding-string value locale-coding-system)))
- (when (interactive-p)
+ (when (called-interactively-p 'interactive)
(message "%s" (if value value "Not set")))
value))
-(defun environment (&optional frame)
- "Return a list of environment variables with their values.
-Each entry in the list is a string of the form NAME=VALUE.
-
-The returned list can not be used to change environment
-variables, only read them. See `setenv' to do that.
-
-If optional parameter FRAME is non-nil, then it should be a
-frame. The function returns the environment of that frame.
-
-The list is constructed by concatenating the elements of
-`process-environment' and the 'environment parameter of the
-selected frame, and removing duplicated and empty values.
-
-Non-ASCII characters are encoded according to the initial value of
-`locale-coding-system', i.e. the elements must normally be decoded for use.
-See `setenv' and `getenv'."
- (let* ((env (append process-environment
- ;; (frame-environment frame)
- nil))
- (scan env)
- prev seen)
- ;; Remove unset variables from the beginning of the list.
- (while (and env
- (or (not (stringp (car env)))
- (not (string-match "=" (car env)))))
- (or (member (car env) seen)
- (setq seen (cons (car env) seen)))
- (setq env (cdr env)
- scan env))
- (let (name)
- (while scan
- (cond ((or (not (stringp (car scan)))
- (not (string-match "=" (car scan))))
- ;; Unset variable.
- (or (member (car scan) seen)
- (setq seen (cons (car scan) seen)))
- (setcdr prev (cdr scan)))
- ((member (setq name (substring (car scan) 0 (string-match "=" (car scan)))) seen)
- ;; Duplicated variable.
- (setcdr prev (cdr scan)))
- (t
- ;; New variable.
- (setq seen (cons name seen))))
- (setq prev scan
- scan (cdr scan))))
- env))
-
(provide 'env)
-;; arch-tag: b7d6a8f7-bc81-46db-8e39-8d721d4ed0b8
;;; env.el ends here