| 1 | ###########################################################################
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| 2 | #
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| 3 | # ReadTxtFile.pm -- base class for import plugins that have plain text files
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| 4 | # A component of the Greenstone digital library software
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| 5 | # from the New Zealand Digital Library Project at the
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| 6 | # University of Waikato, New Zealand.
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| 7 | #
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| 8 | # Copyright (C) 1999-2005 New Zealand Digital Library Project
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| 9 | #
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| 10 | # This program is free software; you can redistribute it and/or modify
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| 11 | # it under the terms of the GNU General Public License as published by
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| 12 | # the Free Software Foundation; either version 2 of the License, or
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| 13 | # (at your option) any later version.
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| 14 | #
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| 15 | # This program is distributed in the hope that it will be useful,
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| 16 | # but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 17 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 18 | # GNU General Public License for more details.
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| 19 | #
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| 20 | # You should have received a copy of the GNU General Public License
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| 21 | # along with this program; if not, write to the Free Software
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| 22 | # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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| 23 | #
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| 24 | ###########################################################################
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| 25 |
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| 26 | package ReadTextFile;
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| 27 |
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| 28 | use strict;
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| 29 | no strict 'subs';
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| 30 | no strict 'refs'; # allow filehandles to be variables and viceversa
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| 31 |
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| 32 | use Encode;
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| 33 |
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| 34 | use multiread;
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| 35 | use encodings;
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| 36 | use unicode;
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| 37 | use textcat;
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| 38 | use doc;
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| 39 | use ghtml;
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| 40 | use gsprintf 'gsprintf';
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| 41 |
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| 42 | use AutoExtractMetadata;
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| 43 |
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| 44 | sub BEGIN {
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| 45 | @ReadTextFile::ISA = ( 'AutoExtractMetadata' );
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| 46 | }
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| 47 |
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| 48 | my $encoding_plus_auto_list =
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| 49 | [ { 'name' => "auto",
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| 50 | 'desc' => "{ReadTextFile.input_encoding.auto}" } ];
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| 51 | push(@{$encoding_plus_auto_list},@{$BasePlugin::encoding_list});
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| 52 |
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| 53 | my $arguments =
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| 54 | [ { 'name' => "input_encoding",
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| 55 | 'desc' => "{ReadTextFile.input_encoding}",
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| 56 | 'type' => "enum",
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| 57 | 'list' => $encoding_plus_auto_list,
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| 58 | 'reqd' => "no" ,
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| 59 | 'deft' => "auto" } ,
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| 60 | { 'name' => "default_encoding",
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| 61 | 'desc' => "{ReadTextFile.default_encoding}",
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| 62 | 'type' => "enum",
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| 63 | 'list' => $BasePlugin::encoding_list,
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| 64 | 'reqd' => "no",
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| 65 | 'deft' => "utf8" },
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| 66 | { 'name' => "extract_language",
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| 67 | 'desc' => "{ReadTextFile.extract_language}",
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| 68 | 'type' => "flag",
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| 69 | 'reqd' => "no" },
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| 70 | { 'name' => "default_language",
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| 71 | 'desc' => "{ReadTextFile.default_language}",
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| 72 | 'type' => "string",
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| 73 | 'deft' => "en",
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| 74 | 'reqd' => "no" }
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| 75 | ];
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| 76 |
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| 77 |
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| 78 | my $options = { 'name' => "ReadTextFile",
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| 79 | 'desc' => "{ReadTextFile.desc}",
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| 80 | 'abstract' => "yes",
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| 81 | 'inherits' => "no",
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| 82 | 'args' => $arguments };
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| 83 |
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| 84 |
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| 85 |
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| 86 | sub new {
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| 87 | my $class = shift (@_);
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| 88 | my ($pluginlist,$inputargs,$hashArgOptLists, $auxiliary) = @_;
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| 89 | push(@$pluginlist, $class);
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| 90 |
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| 91 | push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
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| 92 | push(@{$hashArgOptLists->{"OptList"}},$options);
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| 93 |
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| 94 | my $self = new AutoExtractMetadata($pluginlist, $inputargs, $hashArgOptLists, $auxiliary);
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| 95 |
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| 96 | return bless $self, $class;
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| 97 |
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| 98 | }
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| 99 |
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| 100 |
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| 101 |
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| 102 | # The ReadTextFile read_into_doc_obj() function. This function does all the
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| 103 | # right things to make general options work for a given plugin. It reads in
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| 104 | # a file and sets up a slew of metadata all saved in doc_obj, which
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| 105 | # it then returns as part of a tuple (process_status,doc_obj)
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| 106 | #
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| 107 | # Much of this functionality used to reside in read, but it was broken
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| 108 | # down into a supporting routine to make the code more flexible.
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| 109 | #
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| 110 | # recursive plugins (e.g. RecPlug) and specialized plugins like those
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| 111 | # capable of processing many documents within a single file (e.g.
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| 112 | # GMLPlug) will normally want to implement their own version of
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| 113 | # read_into_doc_obj()
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| 114 | #
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| 115 | # Note that $base_dir might be "" and that $file might
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| 116 | # include directories
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| 117 | sub read_into_doc_obj {
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| 118 | my $self = shift (@_);
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| 119 | my ($pluginfo, $base_dir, $file, $block_hash, $metadata, $processor, $maxdocs, $total_count, $gli) = @_;
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| 120 |
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| 121 | my $outhandle = $self->{'outhandle'};
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| 122 | # should we move this to read? What about secondary plugins?
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| 123 | print STDERR "<Processing n='$file' p='$self->{'plugin_type'}'>\n" if ($gli);
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| 124 | my $pp_file = &util::prettyprint_file($base_dir,$file,$gli);
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| 125 | print $outhandle "$self->{'plugin_type'} processing $pp_file\n"
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| 126 | if $self->{'verbosity'} > 1;
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| 127 |
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| 128 | my ($filename_full_path, $filename_no_path) = &util::get_full_filenames($base_dir, $file);
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| 129 |
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| 130 | # Do encoding stuff
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| 131 | my ($language, $content_encoding) = $self->textcat_get_language_encoding ($filename_full_path);
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| 132 | if ($self->{'verbosity'} > 2) {
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| 133 | print $outhandle "ReadTextFile: reading $file as ($content_encoding,$language)\n";
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| 134 | }
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| 135 |
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| 136 | # create a new document
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| 137 | my $doc_obj = new doc ($filename_full_path, "indexed_doc", $self->{'file_rename_method'});
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| 138 | my $top_section = $doc_obj->get_top_section();
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| 139 |
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| 140 | # this should look at the plugin option too...
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| 141 | $doc_obj->add_utf8_metadata($top_section, "Plugin", "$self->{'plugin_type'}");
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| 142 | $doc_obj->add_utf8_metadata($top_section, "FileSize", (-s $filename_full_path));
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| 143 |
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| 144 | my $plugin_filename_encoding = $self->{'filename_encoding'};
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| 145 | my $filename_encoding = $self->deduce_filename_encoding($file,$metadata,$plugin_filename_encoding);
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| 146 | $self->set_Source_metadata($doc_obj, $filename_full_path, $filename_encoding);
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| 147 |
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| 148 | $doc_obj->add_utf8_metadata($top_section, "Language", $language);
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| 149 | $doc_obj->add_utf8_metadata($top_section, "Encoding", $content_encoding);
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| 150 |
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| 151 | # read in file ($text will be in utf8)
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| 152 | my $text = "";
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| 153 | $self->read_file ($filename_full_path, $content_encoding, $language, \$text);
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| 154 |
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| 155 | if (!length ($text)) {
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| 156 | if ($gli) {
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| 157 | print STDERR "<ProcessingError n='$file' r='File contains no text'>\n";
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| 158 | }
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| 159 | gsprintf($outhandle, "$self->{'plugin_type'}: {ReadTextFile.file_has_no_text}\n", $filename_full_path) if $self->{'verbosity'};
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| 160 |
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| 161 | my $failhandle = $self->{'failhandle'};
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| 162 | gsprintf($failhandle, "$file: " . ref($self) . ": {ReadTextFile.empty_file}\n");
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| 163 | # print $failhandle "$file: " . ref($self) . ": file contains no text\n";
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| 164 | $self->{'num_not_processed'} ++;
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| 165 |
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| 166 | return (0,undef); # what should we return here?? error but don't want to pass it on
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| 167 | }
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| 168 |
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| 169 | # do plugin specific processing of doc_obj
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| 170 | unless (defined ($self->process (\$text, $pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli))) {
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| 171 | $text = '';
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| 172 | undef $text;
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| 173 | print STDERR "<ProcessingError n='$file'>\n" if ($gli);
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| 174 | return (-1,undef);
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| 175 | }
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| 176 | $text='';
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| 177 | undef $text;
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| 178 |
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| 179 | # include any metadata passed in from previous plugins
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| 180 | # note that this metadata is associated with the top level section
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| 181 | $self->add_associated_files($doc_obj, $filename_full_path);
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| 182 | $self->extra_metadata ($doc_obj, $top_section, $metadata);
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| 183 |
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| 184 | # do any automatic metadata extraction
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| 185 | $self->auto_extract_metadata ($doc_obj);
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| 186 |
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| 187 |
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| 188 | # if we haven't found any Title so far, assign one
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| 189 | $self->title_fallback($doc_obj,$top_section,$filename_no_path);
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| 190 |
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| 191 | $self->add_OID($doc_obj);
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| 192 |
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| 193 | return (1,$doc_obj);
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| 194 | }
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| 195 |
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| 196 | # uses the multiread package to read in the entire file pointed to
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| 197 | # by filename and loads the resulting text into $$textref. Input text
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| 198 | # may be in any of the encodings handled by multiread, output text
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| 199 | # will be in utf8
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| 200 | sub read_file {
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| 201 | my $self = shift (@_);
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| 202 | my ($filename, $encoding, $language, $textref) = @_;
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| 203 |
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| 204 | if (!-r $filename)
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| 205 | {
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| 206 | my $outhandle = $self->{'outhandle'};
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| 207 | gsprintf($outhandle, "{ReadTextFile.read_denied}\n", $filename) if $self->{'verbosity'};
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| 208 | # print $outhandle "Read permission denied for $filename\n" if $self->{'verbosity'};
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| 209 | return;
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| 210 | }
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| 211 | $$textref = "";
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| 212 | if (!open (FILE, $filename)) {
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| 213 | gsprintf(STDERR, "ReadTextFile::read_file {ReadTextFile.could_not_open_for_reading} ($!)\n", $filename);
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| 214 | die "\n";
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| 215 | }
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| 216 |
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| 217 | if ($encoding eq "ascii") {
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| 218 | # Replace file 'slurp' with faster implementation
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| 219 | sysread(FILE, $$textref, -s FILE);
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| 220 |
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| 221 | # The old slow way of reading in a file
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| 222 | #undef $/;
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| 223 | #$$textref = <FILE>;
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| 224 | #$/ = "\n";
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| 225 | } else {
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| 226 | my $reader = new multiread();
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| 227 | $reader->set_handle ('ReadTextFile::FILE');
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| 228 | $reader->set_encoding ($encoding);
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| 229 | $reader->read_file ($textref);
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| 230 | }
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| 231 |
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| 232 | # At this point $$textref is a binary byte string
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| 233 | # => turn it into a Unicode aware string, so full
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| 234 | # Unicode aware pattern matching can be used.
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| 235 | # For instance: 's/\x{0101}//g' or '[[:upper:]]'
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| 236 | #
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| 237 |
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| 238 | $$textref = decode("utf8",$$textref);
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| 239 |
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| 240 | close FILE;
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| 241 | }
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| 242 |
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| 243 |
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| 244 | # Not currently used
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| 245 | sub UNUSED_read_file_usingPerlsEncodeModule {
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| 246 | ##sub read_file {
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| 247 | my $self = shift (@_);
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| 248 | my ($filename, $encoding, $language, $textref) = @_;
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| 249 |
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| 250 | if (!-r $filename)
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| 251 | {
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| 252 | my $outhandle = $self->{'outhandle'};
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| 253 | gsprintf($outhandle, "{ReadTextFile.read_denied}\n", $filename) if $self->{'verbosity'};
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| 254 | # print $outhandle "Read permission denied for $filename\n" if $self->{'verbosity'};
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| 255 | return;
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| 256 | }
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| 257 | $$textref = "";
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| 258 | if (!open (FILE, $filename)) {
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| 259 | gsprintf(STDERR, "ReadTextFile::read_file {ReadTextFile.could_not_open_f
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| 260 | or_reading} ($!)\n", $filename);
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| 261 | die "\n";
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| 262 | }
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| 263 |
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| 264 | my $store_slash = $/;
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| 265 | undef $/;
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| 266 | my $text = <FILE>;
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| 267 | $/ = $store_slash;
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| 268 |
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| 269 | $$textref = decode($encoding,$text);
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| 270 |
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| 271 | close FILE;
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| 272 | }
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| 273 |
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| 274 |
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| 275 | sub read_file_no_decoding {
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| 276 | my $self = shift (@_);
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| 277 | my ($filename, $textref) = @_;
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| 278 |
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| 279 | if (!-r $filename)
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| 280 | {
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| 281 | my $outhandle = $self->{'outhandle'};
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| 282 | gsprintf($outhandle, "{ReadTextFile.read_denied}\n", $filename) if $self->{'verbosity'};
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| 283 | # print $outhandle "Read permission denied for $filename\n" if $self->{'verbosity'};
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| 284 | return;
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| 285 | }
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| 286 | $$textref = "";
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| 287 | if (!open (FILE, $filename)) {
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| 288 | gsprintf(STDERR, "ReadTextFile::read_file {ReadTextFile.could_not_open_for_reading} ($!)\n", $filename);
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| 289 | die "\n";
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| 290 | }
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| 291 |
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| 292 | my $reader = new multiread();
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| 293 | $reader->set_handle ('ReadTextFile::FILE');
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| 294 | $reader->read_file_no_decoding ($textref);
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| 295 |
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| 296 | $self->{'reader'} = $reader;
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| 297 |
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| 298 | close FILE;
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| 299 | }
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| 300 |
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| 301 |
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| 302 | sub decode_text {
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| 303 | my $self = shift (@_);
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| 304 | my ($raw_text, $encoding, $language, $textref) = @_;
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| 305 |
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| 306 | my $reader = $self->{'reader'};
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| 307 | if (!defined $reader) {
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| 308 | gsprintf(STDERR, "ReadTextFile::decode_text needs to call ReadTextFile::read_file_no_decoding first\n");
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| 309 | }
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| 310 | else {
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| 311 | $reader->set_encoding($encoding);
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| 312 | $reader->decode_text($raw_text,$textref);
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| 313 |
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| 314 | # At this point $$textref is a binary byte string
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| 315 | # => turn it into a Unicode aware string, so full
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| 316 | # Unicode aware pattern matching can be used.
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| 317 | # For instance: 's/\x{0101}//g' or '[[:upper:]]'
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| 318 |
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| 319 | $$textref = decode("utf8",$$textref);
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| 320 | }
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| 321 | }
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| 322 |
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| 323 |
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| 324 | sub textcat_get_language_encoding {
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| 325 | my $self = shift (@_);
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| 326 | my ($filename) = @_;
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| 327 |
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| 328 | my ($language, $encoding, $extracted_encoding);
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| 329 | if ($self->{'input_encoding'} eq "auto") {
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| 330 | # use textcat to automatically work out the input encoding and language
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| 331 | ($language, $encoding) = $self->get_language_encoding ($filename);
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| 332 | } elsif ($self->{'extract_language'}) {
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| 333 | # use textcat to get language metadata
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| 334 | ($language, $extracted_encoding) = $self->get_language_encoding ($filename);
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| 335 | $encoding = $self->{'input_encoding'};
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| 336 | # don't print this message for english... english in utf8 is identical
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| 337 | # to english in iso-8859-1 (except for some punctuation). We don't have
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| 338 | # a language model for en_utf8, so textcat always says iso-8859-1!
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| 339 | if ($extracted_encoding ne $encoding && $language ne "en" && $self->{'verbosity'}) {
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| 340 | my $plugin_name = ref ($self);
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| 341 | my $outhandle = $self->{'outhandle'};
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| 342 | gsprintf($outhandle, "$plugin_name: {ReadTextFile.wrong_encoding}\n", $filename, $encoding, $extracted_encoding);
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| 343 | }
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| 344 | } else {
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| 345 | $language = $self->{'default_language'};
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| 346 | $encoding = $self->{'input_encoding'};
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| 347 | }
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| 348 |
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| 349 | # print STDERR "**** language encoding of contents of file $filename:\n\t****$language $encoding\n";
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| 350 |
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| 351 | return ($language, $encoding);
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| 352 | }
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| 353 |
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| 354 |
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| 355 | # Uses textcat to work out the encoding and language of the text in
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| 356 | # $filename. All html tags are removed before processing.
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| 357 | # returns an array containing "language" and "encoding"
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| 358 | sub get_language_encoding {
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| 359 | my $self = shift (@_);
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| 360 | my ($filename) = @_;
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| 361 | my $outhandle = $self->{'outhandle'};
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| 362 | my $unicode_format = "";
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| 363 | my $best_language = "";
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| 364 | my $best_encoding = "";
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| 365 |
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| 366 |
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| 367 | # read in file
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| 368 | if (!open (FILE, $filename)) {
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| 369 | gsprintf(STDERR, "ReadTextFile::get_language_encoding {ReadTextFile.could_not_open_for_reading} ($!)\n", $filename);
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| 370 | # this is a pretty bad error, but try to continue anyway
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| 371 | return ($self->{'default_language'}, $self->{'input_encoding'});
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| 372 | }
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| 373 | undef $/;
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| 374 | my $text = <FILE>;
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| 375 | $/ = "\n";
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| 376 | close FILE;
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| 377 |
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| 378 | # check if first few bytes have a Byte Order Marker
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| 379 | my $bom=substr($text,0,2); # check 16bit unicode
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| 380 | if ($bom eq "\xff\xfe") { # little endian 16bit unicode
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| 381 | $unicode_format="unicode";
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| 382 | } elsif ($bom eq "\xfe\xff") { # big endian 16bit unicode
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| 383 | $unicode_format="unicode";
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| 384 | } else {
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| 385 | $bom=substr($text,0,3); # check utf-8
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| 386 | if ($bom eq "\xef\xbb\xbf") { # utf-8 coded FEFF bom
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| 387 | $unicode_format="utf8";
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| 388 | # } elsif ($bom eq "\xef\xbf\xbe") { # utf-8 coded FFFE bom. Error!?
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| 389 | # $unicode_format="utf8";
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| 390 | }
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| 391 | }
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| 392 |
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| 393 | my $found_html_encoding = 0;
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| 394 | # handle html files specially
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| 395 | # XXX this doesn't match plugins derived from HTMLPlug (except ConvertTo)
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| 396 | if (ref($self) eq 'HTMLPlugin' ||
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| 397 | (exists $self->{'converted_to'} && $self->{'converted_to'} eq 'HTML')){
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| 398 |
|
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| 399 | # remove comments in head, including multiline ones, so that we don't match on
|
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| 400 | # inactive tags (those that are nested inside comments)
|
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| 401 | my ($head) = ($text =~ m/<head>(.*)<\/head>/si);
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| 402 | $head = "" unless defined $head; # some files are not proper HTML eg php files
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| 403 | $head =~ s/<!--.*?-->//sg;
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| 404 |
|
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| 405 | # remove <title>stuff</title> -- as titles tend often to be in English
|
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| 406 | # for foreign language documents
|
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| 407 | $text =~ s!<title>.*?</title>!!si;
|
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| 408 |
|
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| 409 | # see if this html file specifies its encoding
|
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| 410 | if ($text =~ /^<\?xml.*encoding="(.+?)"/) {
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| 411 | $best_encoding = $1;
|
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| 412 | }
|
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| 413 | # check the meta http-equiv charset tag
|
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| 414 | elsif ($head =~ m/<meta http-equiv.*content-type.*charset=(.+?)\"/si) {
|
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| 415 | $best_encoding = $1;
|
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| 416 | }
|
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| 417 | if ($best_encoding) { # we extracted an encoding
|
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| 418 | $best_encoding =~ s/-+/_/g;
|
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| 419 | $best_encoding = lc($best_encoding); # lowercase
|
|---|
| 420 | if ($best_encoding eq "utf_8") { $best_encoding = "utf8" }
|
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| 421 | $found_html_encoding = 1;
|
|---|
| 422 | # We shouldn't be modifying this here!!
|
|---|
| 423 | #$self->{'input_encoding'} = $best_encoding;
|
|---|
| 424 | }
|
|---|
| 425 |
|
|---|
| 426 | # remove all HTML tags
|
|---|
| 427 | $text =~ s/<[^>]*>//sg;
|
|---|
| 428 | }
|
|---|
| 429 |
|
|---|
| 430 | # don't need to do textcat if we know the encoding now AND don't need to extract language
|
|---|
| 431 | if($found_html_encoding && !$self->{'extract_language'}) { # encoding specified in html file
|
|---|
| 432 | $best_language = $self->{'default_language'};
|
|---|
| 433 | }
|
|---|
| 434 |
|
|---|
| 435 | else { # need to use textcat to get either the language, or get both language and encoding
|
|---|
| 436 | $self->{'textcat'} = new textcat() if (!defined($self->{'textcat'}));
|
|---|
| 437 |
|
|---|
| 438 | if($found_html_encoding) { # know encoding, find language by limiting search to known encoding
|
|---|
| 439 | my $results = $self->{'textcat'}->classify_contents_for_encoding(\$text, $filename, $best_encoding);
|
|---|
| 440 |
|
|---|
| 441 | my $language;
|
|---|
| 442 | ($language) = $results->[0] =~ m/^([^-]*)(?:-(?:.*))?$/ if (scalar @$results > 0);
|
|---|
| 443 |
|
|---|
| 444 | if (!defined $language || scalar @$results > 3) {
|
|---|
| 445 | # if there were too many results even when restricting results by encoding,
|
|---|
| 446 | # or if there were no results, use default language with the known encoding
|
|---|
| 447 | $best_language = $self->use_default_language($filename);
|
|---|
| 448 | }
|
|---|
| 449 | else { # fewer than 3 results means textcat is more certain, use the first result
|
|---|
| 450 | $best_language = $language;
|
|---|
| 451 | }
|
|---|
| 452 | }
|
|---|
| 453 | else { # don't know encoding or language yet, therefore we use textcat
|
|---|
| 454 | my $results = $self->{'textcat'}->classify_contents(\$text, $filename);
|
|---|
| 455 |
|
|---|
| 456 | # if textcat returns 3 or less possibilities we'll use the first one in the list
|
|---|
| 457 | if (scalar @$results <= 3) { # results will be > 0 when we don't constrain textcat by an encoding
|
|---|
| 458 | my ($language, $encoding) = $results->[0] =~ m/^([^-]*)(?:-(.*))?$/;
|
|---|
| 459 |
|
|---|
| 460 | $language = $self->use_default_language($filename) unless defined $language;
|
|---|
| 461 | $encoding = $self->use_default_encoding($filename) unless defined $encoding;
|
|---|
| 462 |
|
|---|
| 463 | $best_language = $language;
|
|---|
| 464 | $best_encoding = $encoding;
|
|---|
| 465 | }
|
|---|
| 466 | else { # if (scalar @$results > 3) {
|
|---|
| 467 | if ($unicode_format) { # in case the first had a BOM
|
|---|
| 468 | $best_encoding=$unicode_format;
|
|---|
| 469 | }
|
|---|
| 470 | else {
|
|---|
| 471 | # Find the most frequent encoding in the textcat results returned
|
|---|
| 472 | # Returns "" if there's no encoding more frequent than another
|
|---|
| 473 | $best_encoding = $self->{'textcat'}->most_frequent_encoding($results);
|
|---|
| 474 | }
|
|---|
| 475 |
|
|---|
| 476 | if ($best_encoding eq "") { # encoding still not set, use defaults
|
|---|
| 477 | $best_language = $self->use_default_language($filename);
|
|---|
| 478 | $best_encoding = $self->use_default_encoding($filename);
|
|---|
| 479 | }
|
|---|
| 480 | elsif (!$self->{'extract_language'}) { # know encoding but don't need to discover language
|
|---|
| 481 | $best_language = $self->use_default_language($filename);
|
|---|
| 482 | }
|
|---|
| 483 | else { # textcat again using the most frequent encoding or the $unicode_format set above
|
|---|
| 484 | $results = $self->{'textcat'}->classify_contents_for_encoding(\$text, $filename, $best_encoding);
|
|---|
| 485 | my $language;
|
|---|
| 486 | ($language) = $results->[0] =~ m/^([^-]*)(?:-(.*))?$/ if (scalar @$results > 0);
|
|---|
| 487 | if (!defined $language || scalar @$results > 3) {
|
|---|
| 488 | # if no result or too many results, use default language for the encoding previously found
|
|---|
| 489 | $best_language = $self->use_default_language($filename);
|
|---|
| 490 | }
|
|---|
| 491 | else { # fewer than 3 results, use the language of the first result
|
|---|
| 492 | $best_language = $language;
|
|---|
| 493 | }
|
|---|
| 494 | }
|
|---|
| 495 | }
|
|---|
| 496 | }
|
|---|
| 497 | }
|
|---|
| 498 |
|
|---|
| 499 | if($best_encoding eq "" || $best_language eq "") {
|
|---|
| 500 | print STDERR "****Shouldn't happen: encoding and/or language still not set. Using defaults.\n";
|
|---|
| 501 | $best_encoding = $self->use_default_encoding($filename) if $best_encoding eq "";
|
|---|
| 502 | $best_language = $self->use_default_language($filename) if $best_language eq "";
|
|---|
| 503 | }
|
|---|
| 504 | # print STDERR "****Content language: $best_language; Encoding: $best_encoding.\n";
|
|---|
| 505 |
|
|---|
| 506 |
|
|---|
| 507 | if ($best_encoding =~ /^iso_8859/ && &unicode::check_is_utf8($text)) {
|
|---|
| 508 | # the text is valid utf8, so assume that's the real encoding
|
|---|
| 509 | # (since textcat is based on probabilities)
|
|---|
| 510 | $best_encoding = 'utf8';
|
|---|
| 511 | }
|
|---|
| 512 |
|
|---|
| 513 | # check for equivalents where textcat doesn't have some encodings...
|
|---|
| 514 | # eg MS versions of standard encodings
|
|---|
| 515 | if ($best_encoding =~ /^iso_8859_(\d+)/) {
|
|---|
| 516 | my $iso = $1; # which variant of the iso standard?
|
|---|
| 517 | # iso-8859 sets don't use chars 0x80-0x9f, windows codepages do
|
|---|
| 518 | if ($text =~ /[\x80-\x9f]/) {
|
|---|
| 519 | # Western Europe
|
|---|
| 520 | if ($iso == 1 or $iso == 15) { $best_encoding = 'windows_1252' }
|
|---|
| 521 | elsif ($iso == 2) {$best_encoding = 'windows_1250'} # Central Europe
|
|---|
| 522 | elsif ($iso == 5) {$best_encoding = 'windows_1251'} # Cyrillic
|
|---|
| 523 | elsif ($iso == 6) {$best_encoding = 'windows_1256'} # Arabic
|
|---|
| 524 | elsif ($iso == 7) {$best_encoding = 'windows_1253'} # Greek
|
|---|
| 525 | elsif ($iso == 8) {$best_encoding = 'windows_1255'} # Hebrew
|
|---|
| 526 | elsif ($iso == 9) {$best_encoding = 'windows_1254'} # Turkish
|
|---|
| 527 | }
|
|---|
| 528 | }
|
|---|
| 529 |
|
|---|
| 530 | if ($best_encoding !~ /^(ascii|utf8|unicode)$/ &&
|
|---|
| 531 | !defined $encodings::encodings->{$best_encoding}) {
|
|---|
| 532 | if ($self->{'verbosity'}) {
|
|---|
| 533 | gsprintf($outhandle, "ReadTextFile: {ReadTextFile.unsupported_encoding}\n",
|
|---|
| 534 | $filename, $best_encoding, $self->{'default_encoding'});
|
|---|
| 535 | }
|
|---|
| 536 | $best_encoding = $self->{'default_encoding'};
|
|---|
| 537 | }
|
|---|
| 538 |
|
|---|
| 539 | return ($best_language, $best_encoding);
|
|---|
| 540 | }
|
|---|
| 541 |
|
|---|
| 542 |
|
|---|
| 543 | sub use_default_language {
|
|---|
| 544 | my $self = shift (@_);
|
|---|
| 545 | my ($filename) = @_;
|
|---|
| 546 |
|
|---|
| 547 | if ($self->{'verbosity'}>2) {
|
|---|
| 548 | gsprintf($self->{'outhandle'},
|
|---|
| 549 | "ReadTextFile: {ReadTextFile.could_not_extract_language}\n",
|
|---|
| 550 | $filename, $self->{'default_language'});
|
|---|
| 551 | }
|
|---|
| 552 | return $self->{'default_language'};
|
|---|
| 553 | }
|
|---|
| 554 |
|
|---|
| 555 | sub use_default_encoding {
|
|---|
| 556 | my $self = shift (@_);
|
|---|
| 557 | my ($filename) = @_;
|
|---|
| 558 |
|
|---|
| 559 | if ($self->{'verbosity'}>2) {
|
|---|
| 560 | gsprintf($self->{'outhandle'},
|
|---|
| 561 | "ReadTextFile: {ReadTextFile.could_not_extract_encoding}\n",
|
|---|
| 562 | $filename, $self->{'default_encoding'});
|
|---|
| 563 | }
|
|---|
| 564 | return $self->{'default_encoding'};
|
|---|
| 565 | }
|
|---|
| 566 |
|
|---|
| 567 | # Overridden by exploding plugins (eg. ISISPlug)
|
|---|
| 568 | sub clean_up_after_exploding
|
|---|
| 569 | {
|
|---|
| 570 | my $self = shift(@_);
|
|---|
| 571 | }
|
|---|
| 572 |
|
|---|
| 573 |
|
|---|
| 574 | 1;
|
|---|
