;;; env.el --- functions to manipulate environment variables
;; Copyright (C) 1991, 1994, 2000, 2001, 2002, 2003, 2004,
-;; 2005, 2006 Free Software Foundation, Inc.
+;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: processes, unix
;; 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)
+;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
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)))))
+ (let ((str (substring enventry 0
+ (string-match "=" enventry))))
+ (if (multibyte-string-p str)
+ (decode-coding-string
+ str locale-coding-system t)
+ str)))
(append process-environment
- (frame-parameter (frame-with-environment) 'environment)
- global-environment))
+ ;;(frame-environment)
+ ))
nil mustmatch nil 'read-envvar-name-history))
;; History list for VALUE argument to setenv.
start (+ (match-beginning 0) 1)))))
string))
+
+(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."
+ (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 pattern (car env)))
+ (cdr env)
+ ;; Try to find existing entry for VARIABLE in ENV.
+ (while (and scan (stringp (car scan)))
+ (when (string-match 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 frame)
+(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.
This function always replaces environment variables in the new
value when called interactively.
-If VARIABLE is set in `process-environment', then this function
-modifies its value there. Otherwise, this function works by
-modifying either `global-environment' or the environment
-belonging to the selected frame, depending on the value of
-`local-environment-variables'.
-
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.
-If optional parameter FRAME is non-nil, then it should be a a
-frame. If the specified frame has its own set of environment
-variables, this function will modify VARIABLE in it. Note that
-frames on the same terminal device usually share their
-environment, so calling `setenv' on one of them affects the
-others as well.
+This function works by modifying `process-environment'.
As a special case, setting variable `TZ' calls `set-time-zone-rule' as
a side-effect."
(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 variable) "\\(=\\|\\'\\)"))
- (case-fold-search nil)
- (frame-env (frame-parameter (frame-with-environment frame) 'environment))
- (frame-forced (not frame))
- (scan process-environment)
- found)
- (setq frame (frame-with-environment frame))
- (if (string-equal "TZ" variable)
- (set-time-zone-rule value))
- (block nil
- ;; Look for an existing entry for VARIABLE; try `process-environment' first.
- (while (and scan (stringp (car scan)))
- (when (string-match pattern (car scan))
- (if value
- (setcar scan (concat variable "=" value))
- ;; Leave unset variables in `process-environment',
- ;; otherwise the overridden value in `global-environment'
- ;; or frame-env would become unmasked.
- (setcar scan variable))
- (return value))
- (setq scan (cdr scan)))
-
- ;; Look in the local or global environment, whichever is relevant.
- (let ((local-var-p (and frame-env
- (or frame-forced
- (eq t local-environment-variables)
- (member variable local-environment-variables)))))
- (setq scan (if local-var-p
- frame-env
- global-environment))
- (while scan
- (when (string-match pattern (car scan))
- (if value
- (setcar scan (concat variable "=" value))
- (if local-var-p
- (set-frame-parameter frame 'environment
- (delq (car scan) frame-env))
- (setq global-environment (delq (car scan) global-environment))))
- (return value))
- (setq scan (cdr scan)))
-
- ;; VARIABLE is not in any environment list.
- (if value
- (if local-var-p
- (set-frame-parameter frame 'environment
- (cons (concat variable "=" value)
- frame-env))
- (setq global-environment
- (cons (concat variable "=" value)
- global-environment))))
- (return value)))))
+ (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.
the environment. Otherwise, value is a string.
If optional parameter FRAME is non-nil, then it should be a
-frame. If that frame has its own set of environment variables,
-this function will look up VARIABLE in there.
+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 either `global-environment' or the environment list of
-the selected frame, depending on the value of
-`local-environment-variables'."
+VARIABLE. If it is not found there, then it continues the search
+in the environment list of the selected frame."
(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))))
+ variable)
+ frame)))
(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))
-(defun environment ()
+(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.
-The list is constructed from elements of `process-environment',
-`global-environment' and the local environment list of the
-selected frame, as specified by `local-environment-variables'.
+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 (let ((local-env (frame-parameter (frame-with-environment)
- 'environment)))
- (cond ((or (not local-environment-variables)
- (not local-env))
- (append process-environment global-environment nil))
- ((consp local-environment-variables)
- (let ((e (reverse process-environment)))
- (dolist (entry local-environment-variables)
- (setq e (cons (getenv entry) e)))
- (append (nreverse e) global-environment nil)))
- (t
- (append process-environment local-env nil)))))
- scan seen)
- ;; Find the first valid entry in env.
- (while (and env (stringp (car env))
- (or (not (string-match "=" (car env)))
- (member (substring (car env) 0 (string-match "=" (car env))) seen)))
- (setq seen (cons (car env) seen)
- env (cdr env)))
- (setq scan env)
- (while (and (cdr scan) (stringp (cadr scan)))
- (let* ((match (string-match "=" (cadr scan)))
- (name (substring (cadr scan) 0 match)))
- (cond ((not match)
+ (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.
- (setq seen (cons name seen))
- (setcdr scan (cddr scan)))
- ((member name seen)
- ;; Duplicate variable.
- (setcdr scan (cddr scan)))
+ (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)
- scan (cdr scan))))))
+ (setq seen (cons name seen))))
+ (setq prev scan
+ scan (cdr scan))))
env))
-(defmacro let-environment (varlist &rest body)
- "Evaluate BODY with environment variables set according to VARLIST.
-The environment variables are then restored to their previous
-values.
-The value of the last form in BODY is returned.
-
-Each element of VARLIST is either a string (which variable is
-then removed from the environment), or a list (NAME
-VALUEFORM) (which sets NAME to the value of VALUEFORM, a string).
-All the VALUEFORMs are evaluated before any variables are set."
- (declare (indent 2))
- (let ((old-env (make-symbol "old-env"))
- (name (make-symbol "name"))
- (value (make-symbol "value"))
- (entry (make-symbol "entry"))
- (frame (make-symbol "frame")))
- `(let ((,frame (selected-frame))
- ,old-env)
- ;; Evaluate VALUEFORMs and replace them in VARLIST with their values.
- (dolist (,entry ,varlist)
- (unless (stringp ,entry)
- (if (cdr (cdr ,entry))
- (error "`let-environment' bindings can have only one value-form"))
- (setcdr ,entry (eval (cadr ,entry)))))
- ;; Set the variables.
- (dolist (,entry ,varlist)
- (let ((,name (if (stringp ,entry) ,entry (car ,entry)))
- (,value (if (consp ,entry) (cdr ,entry))))
- (setq ,old-env (cons (cons ,name (getenv ,name)) ,old-env))
- (setenv ,name ,value)))
- (unwind-protect
- (progn ,@body)
- ;; Restore old values.
- (with-selected-frame (if (frame-live-p ,frame)
- ,frame
- (selected-frame))
- (dolist (,entry ,old-env)
- (setenv (car ,entry) (cdr ,entry))))))))
-
(provide 'env)
-;;; arch-tag: b7d6a8f7-bc81-46db-8e39-8d721d4ed0b8
+;; arch-tag: b7d6a8f7-bc81-46db-8e39-8d721d4ed0b8
;;; env.el ends here