idna.el

   1 ;;; idna.el --- Internationalizing Domain Names in Applications.
   2
   3 ;; Copyright (C) 2003  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., 59 Temple Place - Suite 330,
  21 ;; Boston, MA 02111-1307, 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 "env CHARSET=UTF-8 idn"
  56   "Name of the GNU Libidn \"idn\" application."
  57   :type 'string
  58   :group 'idna)
  59
  60 (defcustom idna-to-ascii-parameters "--quiet --idna-to-ascii"
  61   "Parameters passed to `idna-program' to invoke IDNA ToASCII mode."
  62   :type 'string
  63   :group 'idna)
  64
  65 (defcustom idna-to-unicode-parameters "--quiet --idna-to-unicode"
  66   "Parameters passed `idna-program' to invoke IDNA ToUnicode mode."
  67   :type 'string
  68   :group 'idna)
  69
  70 ;; Internal process handling:
  71
  72 (defvar idna-to-ascii-process nil
  73   "Internal variable holding process for ToASCII.")
  74 (defvar idna-to-ascii-response nil
  75   "Internal variable holding response data received from ToASCII process.")
  76
  77 (defun idna-to-ascii-response-clear ()
  78   (setq idna-to-ascii-response nil))
  79
  80 (defun idna-to-ascii-response ()
  81   (while (and (eq (process-status idna-to-ascii-process) 'run)
  82               (null idna-to-ascii-response))
  83     (accept-process-output idna-to-ascii-process 1))
  84   idna-to-ascii-response)
  85
  86 (defun idna-to-ascii-filter (process string)
  87   (setq idna-to-ascii-response (concat idna-to-ascii-response string)))
  88
  89 (defun idna-to-ascii-process ()
  90   (if (and idna-to-ascii-process
  91            (eq (process-status idna-to-ascii-process) 'run))
  92       idna-to-ascii-process
  93     (if idna-to-ascii-process
  94         (condition-case ()
  95             (kill-process idna-to-ascii-process)
  96           (error)))
  97     (when (setq idna-to-ascii-process
  98                 (start-process "idna" nil
  99                                shell-file-name shell-command-switch
 100                                (concat idna-program " "
 101                                        idna-to-ascii-parameters)))
 102       (set-process-filter idna-to-ascii-process 'idna-to-ascii-filter)
 103       (set-process-coding-system idna-to-ascii-process 'utf-8 'utf-8)
 104       (process-kill-without-query idna-to-ascii-process))
 105     idna-to-ascii-process))
 106
 107 (defvar idna-to-unicode-process nil
 108   "Internal variable holding process for ToASCII.")
 109 (defvar idna-to-unicode-response nil
 110   "Internal variable holding response data received from ToASCII process.")
 111
 112 (defun idna-to-unicode-response-clear ()
 113   (setq idna-to-unicode-response nil))
 114
 115 (defun idna-to-unicode-response ()
 116   (while (and (eq (process-status idna-to-unicode-process) 'run)
 117               (null idna-to-unicode-response))
 118     (accept-process-output idna-to-unicode-process 1))
 119   idna-to-unicode-response)
 120
 121 (defun idna-to-unicode-filter (process string)
 122   (setq idna-to-unicode-response (concat idna-to-unicode-response string)))
 123
 124 (defun idna-to-unicode-process ()
 125   (if (and idna-to-unicode-process
 126            (eq (process-status idna-to-unicode-process) 'run))
 127       idna-to-unicode-process
 128     (if idna-to-unicode-process
 129         (condition-case ()
 130             (kill-process idna-to-unicode-process)
 131           (error)))
 132     (when (setq idna-to-unicode-process
 133                 (start-process "idna" nil
 134                                shell-file-name shell-command-switch
 135                                (concat idna-program " "
 136                                        idna-to-unicode-parameters)))
 137       (set-process-filter idna-to-unicode-process 'idna-to-unicode-filter)
 138       (set-process-coding-system idna-to-unicode-process 'utf-8 'utf-8)
 139       (process-kill-without-query idna-to-unicode-process))
 140     idna-to-unicode-process))
 141
 142 ;; IDNA Elisp API:
 143
 144 (defun idna-to-ascii (str)
 145   "Returns an ASCII Compatible Encoding (ACE) of STR.
 146 It is computed by the IDNA ToASCII operation, after converting the
 147 input to UTF-8."
 148   (let ((proc (idna-to-ascii-process))
 149         string)
 150     (if (null proc)
 151         (error "Cannot start idn application")
 152       (idna-to-ascii-response-clear)
 153       (process-send-string proc (concat str "\n"))
 154       (setq string (idna-to-ascii-response))
 155       (if (string= (substring string (1- (length string))) "\n")
 156           (substring string 0 (1- (length string)))
 157         string))))
 158
 159 (defun idna-to-unicode (str)
 160   "Returns a possibly multibyte string after decoding STR.
 161 It is computed by the IDNA ToUnicode operation."
 162   (let ((proc (idna-to-unicode-process))
 163         string)
 164     (if (null proc)
 165         (error "Cannot start idn application")
 166       (idna-to-unicode-response-clear)
 167       (process-send-string proc (concat str "\n"))
 168       (setq string (idna-to-unicode-response))
 169       (if (string= (substring string (1- (length string))) "\n")
 170           (substring string 0 (1- (length string)))
 171         string))))
 172
 173 (provide 'idna)
 174
 175 ;;; idna.el ends here