src/idna.el

   1 ;;; idna.el --- Internationalizing Domain Names in Applications.
   2
   3 ;; Copyright (C) 2003, 2005  Simon Josefsson
   4 ;; Keywords: idna, idn, domain name, internationalization
   5
   6 ;; This file is part of GNU Libidn.
   7
   8 ;; GNU Libidn is free software; you can redistribute it and/or modify
   9 ;; it under the terms of the GNU General Public License as published by
  10 ;; the Free Software Foundation; either version 2, or (at your option)
  11 ;; any later version.
  12
  13 ;; GNU Libidn is distributed in the hope that it will be useful,
  14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;; GNU General Public License for more details.
  17
  18 ;; You should have received a copy of the GNU General Public License
  19 ;; along with GNU Libidn; see the file COPYING.  If not, write to the
  20 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21 ;; Boston, MA 02110-1301, USA.
  22
  23 ;;; Commentary:
  24
  25 ;; A simple wrapper around the command line "idn" utility in GNU
  26 ;; Libidn to make IDNA ToASCII and ToUnicode operations available in
  27 ;; Emacs.
  28
  29 ;; Example:
  30 ;;
  31 ;; (idna-to-ascii "räksmörgås.gnu.org")
  32 ;; => "xn--rksmrgs-5wao1o.gnu.org"
  33 ;;
  34 ;; (idna-to-ascii "www.gnu.org")
  35 ;; => "www.gnu.org"
  36 ;;
  37 ;; (idna-to-unicode "xn--rksmrgs-5wao1o.gnu.org")
  38 ;; => "räksmörgås.gnu.org"
  39 ;;
  40 ;; (idna-to-unicode "www.gnu.org")
  41 ;; => "www.gnu.org"
  42
  43 ;; Todo: Support AllowUnassigned and UseSTD3ASCIIRules somehow?
  44
  45 ;; This package is useless unless your emacs has at least partial
  46 ;; support for the UTF-8 coding system.
  47
  48 ;; Report bugs to bug-libidn@gnu.org.
  49
  50 ;;; Code:
  51
  52 (defgroup idna nil
  53   "Internationalizing Domain Names in Applications.")
  54
  55 (defcustom idna-program "idn"
  56   "Name of the GNU Libidn \"idn\" application."
  57   :type 'string
  58   :group 'idna)
  59
  60 (defcustom idna-environment '("CHARSET=UTF-8")
  61   "List of environment variable definitions prepended to `process-environment'."
  62   :type '(repeat string)
  63   :group 'idna)
  64
  65 (defcustom idna-to-ascii-parameters '("--quiet"
  66                                       "--idna-to-ascii"
  67                                       "--usestd3asciirules")
  68   "Parameters passed to `idna-program' to invoke IDNA ToASCII mode."
  69   :type '(repeat string)
  70   :group 'idna)
  71
  72 (defcustom idna-to-unicode-parameters '("--quiet"
  73                                         "--idna-to-unicode"
  74                                         "--usestd3asciirules")
  75   "Parameters passed `idna-program' to invoke IDNA ToUnicode mode."
  76   :type '(repeat string)
  77   :group 'idna)
  78
  79 ;; Internal process handling:
  80
  81 (defvar idna-to-ascii-process nil
  82   "Internal variable holding process for ToASCII.")
  83 (defvar idna-to-ascii-response nil
  84   "Internal variable holding response data received from ToASCII process.")
  85
  86 (defun idna-to-ascii-response-clear ()
  87   (setq idna-to-ascii-response nil))
  88
  89 (defun idna-to-ascii-response ()
  90   (while (and (eq (process-status idna-to-ascii-process) 'run)
  91               (null idna-to-ascii-response))
  92     (accept-process-output idna-to-ascii-process 1))
  93   idna-to-ascii-response)
  94
  95 (defun idna-to-ascii-filter (process string)
  96   (setq idna-to-ascii-response (concat idna-to-ascii-response string)))
  97
  98 (defun idna-to-ascii-process ()
  99   (if (and idna-to-ascii-process
 100            (eq (process-status idna-to-ascii-process) 'run))
 101       idna-to-ascii-process
 102     (if idna-to-ascii-process
 103         (condition-case ()
 104             (kill-process idna-to-ascii-process)
 105           (error)))
 106     (when (setq idna-to-ascii-process
 107                 (let ((process-environment (append idna-environment
 108                                                    process-environment)))
 109                   (apply 'start-process "idna" nil idna-program
 110                          idna-to-ascii-parameters)))
 111       (set-process-filter idna-to-ascii-process 'idna-to-ascii-filter)
 112       (set-process-coding-system idna-to-ascii-process 'utf-8 'utf-8)
 113       (process-kill-without-query idna-to-ascii-process))
 114     idna-to-ascii-process))
 115
 116 (defvar idna-to-unicode-process nil
 117   "Internal variable holding process for ToASCII.")
 118 (defvar idna-to-unicode-response nil
 119   "Internal variable holding response data received from ToASCII process.")
 120
 121 (defun idna-to-unicode-response-clear ()
 122   (setq idna-to-unicode-response nil))
 123
 124 (defun idna-to-unicode-response ()
 125   (while (and (eq (process-status idna-to-unicode-process) 'run)
 126               (null idna-to-unicode-response))
 127     (accept-process-output idna-to-unicode-process 1))
 128   idna-to-unicode-response)
 129
 130 (defun idna-to-unicode-filter (process string)
 131   (setq idna-to-unicode-response (concat idna-to-unicode-response string)))
 132
 133 (defun idna-to-unicode-process ()
 134   (if (and idna-to-unicode-process
 135            (eq (process-status idna-to-unicode-process) 'run))
 136       idna-to-unicode-process
 137     (if idna-to-unicode-process
 138         (condition-case ()
 139             (kill-process idna-to-unicode-process)
 140           (error)))
 141     (when (setq idna-to-unicode-process
 142                 (let ((process-environment (append idna-environment
 143                                                    process-environment)))
 144                   (apply 'start-process "idna" nil idna-program
 145                          idna-to-unicode-parameters)))
 146       (set-process-filter idna-to-unicode-process 'idna-to-unicode-filter)
 147       (set-process-coding-system idna-to-unicode-process 'utf-8 'utf-8)
 148       (process-kill-without-query idna-to-unicode-process))
 149     idna-to-unicode-process))
 150
 151 ;; IDNA Elisp API:
 152
 153 (defun idna-to-ascii (str)
 154   "Returns an ASCII Compatible Encoding (ACE) of STR.
 155 It is computed by the IDNA ToASCII operation, after converting the
 156 input to UTF-8."
 157   (let ((proc (idna-to-ascii-process))
 158         string)
 159     (if (null proc)
 160         (error "Cannot start idn application (to-ascii)")
 161       (idna-to-ascii-response-clear)
 162       (process-send-string proc (concat str "\n"))
 163       (setq string (idna-to-ascii-response))
 164       (if (and string (string= (substring string (1- (length string))) "\n"))
 165           (substring string 0 (1- (length string)))
 166         string))))
 167
 168 (defun idna-to-unicode (str)
 169   "Returns a possibly multibyte string after decoding STR.
 170 It is computed by the IDNA ToUnicode operation."
 171   (let ((proc (idna-to-unicode-process))
 172         string)
 173     (if (null proc)
 174         (error "Cannot start idn application (to-unicode)")
 175       (idna-to-unicode-response-clear)
 176       (process-send-string proc (concat str "\n"))
 177       (setq string (idna-to-unicode-response))
 178       (if (and string (string= (substring string (1- (length string))) "\n"))
 179           (substring string 0 (1- (length string)))
 180         string))))
 181
 182 (defun idna-shutdown ()
 183   "Kill the IDNA related processes."
 184   (interactive)
 185   (if (and idna-to-ascii-process
 186            (eq (process-status idna-to-ascii-process) 'run))
 187       (kill-process idna-to-ascii-process))
 188   (if (and idna-to-unicode-process
 189            (eq (process-status idna-to-unicode-process) 'run))
 190       (kill-process idna-to-unicode-process)))
 191
 192 (provide 'idna)
 193
 194 ;;; idna.el ends here