1 # $Id: EncodingDetect.pm,v 1.6 2007/02/07 09:33:50 grant Exp $

     2 

     3 package XML::SAX::PurePerl; # NB, not ::EncodingDetect!

     4 

     5 use strict;

     6 

     7 sub encoding_detect {

     8     my ($parser, $reader) = @_;

     9     

    10     my $error = "Invalid byte sequence at start of file";

    11     

    12     my $data = $reader->data;

    13     if ($data =~ /^\x00\x00\xFE\xFF/) {

    14         # BO-UCS4-be

    15         $reader->move_along(4);

    16         $reader->set_encoding('UCS-4BE');

    17         return;

    18     }

    19     elsif ($data =~ /^\x00\x00\xFF\xFE/) {

    20         # BO-UCS-4-2143

    21         $reader->move_along(4);

    22         $reader->set_encoding('UCS-4-2143');

    23         return;

    24     }

    25     elsif ($data =~ /^\x00\x00\x00\x3C/) {

    26         $reader->set_encoding('UCS-4BE');

    27         return;

    28     }

    29     elsif ($data =~ /^\x00\x00\x3C\x00/) {

    30         $reader->set_encoding('UCS-4-2143');

    31         return;

    32     }

    33     elsif ($data =~ /^\x00\x3C\x00\x00/) {

    34         $reader->set_encoding('UCS-4-3412');

    35         return;

    36     }

    37     elsif ($data =~ /^\x00\x3C\x00\x3F/) {

    38         $reader->set_encoding('UTF-16BE');

    39         return;

    40     }

    41     elsif ($data =~ /^\xFF\xFE\x00\x00/) {

    42         # BO-UCS-4LE

    43         $reader->move_along(4);

    44         $reader->set_encoding('UCS-4LE');

    45         return;

    46     }

    47     elsif ($data =~ /^\xFF\xFE/) {

    48         $reader->move_along(2);

    49         $reader->set_encoding('UTF-16LE');

    50         return;

    51     }

    52     elsif ($data =~ /^\xFE\xFF\x00\x00/) {

    53         $reader->move_along(4);

    54         $reader->set_encoding('UCS-4-3412');

    55         return;

    56     }

    57     elsif ($data =~ /^\xFE\xFF/) {

    58         $reader->move_along(2);

    59         $reader->set_encoding('UTF-16BE');

    60         return;

    61     }

    62     elsif ($data =~ /^\xEF\xBB\xBF/) { # UTF-8 BOM

    63         $reader->move_along(3);

    64         $reader->set_encoding('UTF-8');

    65         return;

    66     }

    67     elsif ($data =~ /^\x3C\x00\x00\x00/) {

    68         $reader->set_encoding('UCS-4LE');

    69         return;

    70     }

    71     elsif ($data =~ /^\x3C\x00\x3F\x00/) {

    72         $reader->set_encoding('UTF-16LE');

    73         return;

    74     }

    75     elsif ($data =~ /^\x3C\x3F\x78\x6D/) {

    76         # $reader->set_encoding('UTF-8');

    77         return;

    78     }

    79     elsif ($data =~ /^\x3C\x3F\x78/) {

    80         # $reader->set_encoding('UTF-8');

    81         return;

    82     }

    83     elsif ($data =~ /^\x3C\x3F/) {

    84         # $reader->set_encoding('UTF-8');

    85         return;

    86     }

    87     elsif ($data =~ /^\x3C/) {

    88         # $reader->set_encoding('UTF-8');

    89         return;

    90     }

    91     elsif ($data =~ /^[\x20\x09\x0A\x0D]+\x3C[^\x3F]/) {

    92         # $reader->set_encoding('UTF-8');

    93         return;

    94     }

    95     elsif ($data =~ /^\x4C\x6F\xA7\x94/) {

    96         $reader->set_encoding('EBCDIC');

    97         return;

    98     }

    99     

   100     warn("Unable to recognise encoding of this document");

   101     return;

   102 }

   103 

   104 1;

   105