source: trunk/gsdl/perllib/ghtml.pm@ 8886

Last change on this file since 8886 was 8886, checked in by mdewsnip, 19 years ago

Bug fix in html2txt function, thanks to Emanuel Dejanu.

  • Property svn:keywords set to Author Date Id Revision
File size: 13.5 KB
Line 
1###########################################################################
2#
3# ghtml.pm -- this used to be called html.pm but it clashed
4# with the existing html module under windows
5#
6# A component of the Greenstone digital library software
7# from the New Zealand Digital Library Project at the
8# University of Waikato, New Zealand.
9#
10# Copyright (C) 1999 New Zealand Digital Library Project
11#
12# This program is free software; you can redistribute it and/or modify
13# it under the terms of the GNU General Public License as published by
14# the Free Software Foundation; either version 2 of the License, or
15# (at your option) any later version.
16#
17# This program is distributed in the hope that it will be useful,
18# but WITHOUT ANY WARRANTY; without even the implied warranty of
19# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20# GNU General Public License for more details.
21#
22# You should have received a copy of the GNU General Public License
23# along with this program; if not, write to the Free Software
24# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25#
26###########################################################################
27
28package ghtml;
29
30use unicode;
31
32# htmlsafe(TEXT)
33#
34# Converts SGML meta characters in TEXT to entity references.
35#
36sub htmlsafe
37{
38 $_[0] =~ s/&/&/osg;
39 $_[0] =~ s/</&lt;/osg;
40 $_[0] =~ s/>/&gt;/osg;
41 $_[0] =~ s/\"/&quot;/osg;
42}
43
44# unescape_html(TEXT)
45#
46# Converts HTML entities into their original form.
47#
48sub unescape_html
49{
50 my ($html) = @_;
51
52 $html =~ s/&amp;/&/osg;
53 $html =~ s/&lt;/</osg;
54 $html =~ s/&gt;/>/osg;
55 $html =~ s/&quot;/\"/osg;
56
57 return $html;
58}
59
60# urlsafe(TEXT)
61#
62# Converts characters not allowed in a URL to their hex representation.
63#
64sub urlsafe
65{
66 $_[0] =~ s/[\x09\x20\x22\x3c\x3e\x5b\x5c\x5d\x5e\x60\x7b\x7c\x7d\x7e\?\=\&\+_\/]/sprintf("%%%2x", ord($&))/gse;
67}
68
69# dmsafe
70#
71# Converts characters which could make display.pl or html crack to their entity references.
72# Don't use this on dm macros as they will no longer be recognisable by dm (which
73# by the way, is the whole idea).
74# -- Rodger 12/1/98
75sub dmsafe {
76 my ($s) = $_[0];
77 $s =~ s/&/&amp;/osg; # for html
78 $s =~ s/</&lt;/osg; # for html
79 $s =~ s/>/&gt;/osg; # for html
80 $s =~ s/\_/&#095;/osg; # for dm (we have a convention of starting macros with _
81 $s =~ s/\"/&quot;/osg; # for html (don't want to be interpreted as a quote)
82 $s =~ s/\{/&#123;/osg; # for dm blocks
83 $s =~ s/\}/&#125;/osg; # for dm blocks
84 $s =~ s/\\/&#092;/osg; # for dm (dm removes naturally occurring backquotes)
85 return $s;
86}
87
88
89# named entry to the standard html font
90my %charnetosf = ("Agrave"=> "192", "Aacute"=> "193", "Acirc" => "194", "Atilde"=> "195",
91 "Auml" => "196", "Aring" => "197", "AElig" => "198", "Ccedil"=> "199",
92 "Egrave"=> "200", "Eacute"=> "201", "Ecirc" => "202", "Euml" => "203",
93 "Igrave"=> "204", "Iacute"=> "205", "Icirc" => "206", "Iuml" => "207",
94 "ETH" => "208", "Ntilde"=> "209", "Ograve"=> "210", "Oacute"=> "211",
95 "Ocirc" => "212", "Otilde"=> "213", "Ouml" => "214",
96 "Oslash"=> "216", "Ugrave"=> "217", "Uacute"=> "218", "Ucirc" => "219",
97 "Uuml" => "220", "Yacute"=> "221", "THORN" => "222", "szlig" => "223",
98 "agrave"=> "224", "aacute"=> "225", "acirc" => "226", "atilde"=> "227",
99 "auml" => "228", "aring" => "229", "aelig" => "230", "ccedil"=> "231",
100 "egrave"=> "232", "eacute"=> "233", "ecirc" => "234", "euml" => "235",
101 "igrave"=> "236", "iacute"=> "237", "icirc" => "238", "iuml" => "239",
102 "eth" => "240", "ntilde"=> "241", "ograve"=> "242", "oacute"=> "243",
103 "ocirc" => "244", "otilde"=> "245", "ouml" => "246",
104 "oslash"=> "248", "ugrave"=> "249", "uacute"=> "250", "ucirc" => "251",
105 "uuml" => "252", "yacute"=> "253", "thorn" => "254", "yuml" => "255");
106
107my %symnetosf = ("quot" => "34", "amp" => "38", "lt" => "60", "gt" => "62",
108 "nbsp" => "160", "iexcl" => "161", "cent" => "162", "pound" => "163",
109 "curren"=> "164", "yen" => "165", "brvbar"=> "166", "sect" => "167",
110 "uml" => "168", "copy" => "169", "ordf" => "170", "laquo" => "171",
111 "not" => "172", "shy" => "173", "reg" => "174", "macr" => "175",
112 "deg" => "176", "plusmn"=> "177", "sup2" => "178", "sup3" => "179",
113 "acute" => "180", "micro" => "181", "para" => "182", "middot"=> "183",
114 "cedil" => "184", "sup1" => "185", "ordm" => "186", "raquo" => "187",
115 "frac14"=> "188", "frac12"=> "189", "frac34"=> "190", "iquest"=> "191",
116 "times" => "215", "divide"=> "247");
117
118
119
120# standard font to plain text
121my %sftotxt = ("32" => " ", "33" => "!", "34" => "\"", "35" => "\#", "36" => "\$",
122 "37" => "\%", "38" => "&", "39" => "'", "40" => "(", "41" => ")",
123 "42" => "*", "43" => "+", "44" => ",", "45" => "-", "46" => ".",
124 "47" => "/", "48" => "0", "49" => "1", "50" => "2", "51" => "3",
125 "52" => "4", "53" => "5", "54" => "6", "55" => "7", "56" => "8",
126 "57" => "9", "58" => ":", "59" => ";", "60" => "<", "61" => "=",
127 "62" => ">", "63" => "?", "64" => "\@", "65" => "A", "66" => "B",
128 "57" => "9", "58" => ":", "59" => ";", "61" => "=",
129 "63" => "?", "64" => "\@", "65" => "A", "66" => "B",
130 "67" => "C", "68" => "D", "69" => "E", "70" => "F", "71" => "G",
131 "72" => "H", "73" => "I", "74" => "J", "75" => "K", "76" => "L",
132 "77" => "M", "78" => "N", "79" => "O", "80" => "P", "81" => "Q",
133 "82" => "R", "83" => "S", "84" => "T", "85" => "U", "86" => "V",
134 "87" => "W", "88" => "X", "89" => "Y", "90" => "Z", "91" => "[",
135 "92" => "\\", "93" => "]", "94" => "^", "95" => "_", "96" => "`",
136 "97" => "a", "98" => "b", "99" => "c", "100" => "d", "101" => "e",
137 "102" => "f", "103" => "g", "104" => "h", "105" => "i", "106" => "j",
138 "107" => "k", "108" => "l", "109" => "m", "110" => "n", "111" => "o",
139 "112" => "p", "113" => "q", "114" => "r", "115" => "s", "116" => "t",
140 "117" => "u", "118" => "v", "119" => "w", "120" => "x", "121" => "y",
141 "122" => "z", "123" => "{", "124" => "|", "125" => "}", "126" => "~",
142 "130" => ",", "131" => "f", "132" => "\"", "133" => "...", "139" => "<",
143 "140" => "OE", "145" => "'", "146" => "'", "147" => "\"", "148" => "\"",
144 "149" => "o", "150" => "--", "151" => "-", "152" => "~", "153" => "TM",
145 "155" => ">", "156" => "oe", "159" => "Y", "160" => " ", "178" => "2",
146 "179" => "3", "185" => "1", "188" => "1/4", "189" => "1/2", "190" => "3/4",
147 "192" => "A", "193" => "A", "194" => "A", "195" => "A", "196" => "A",
148 "197" => "A", "198" => "AE", "199" => "C", "200" => "E", "201" => "E",
149 "202" => "E", "203" => "E", "204" => "I", "205" => "I", "206" => "I",
150 "207" => "I", "208" => "D", "209" => "N", "210" => "O", "211" => "O",
151 "212" => "O", "213" => "O", "214" => "O", "215" => "*", "216" => "O",
152 "217" => "U", "218" => "U", "219" => "U", "220" => "U", "221" => "Y",
153 "223" => "ss", "224" => "a", "225" => "a", "226" => "a", "227" => "a",
154 "228" => "a", "229" => "a", "230" => "ae", "231" => "c", "232" => "e",
155 "233" => "e", "234" => "e", "235" => "e", "236" => "i", "237" => "i",
156 "238" => "i", "239" => "i", "241" => "n", "242" => "o", "243" => "o",
157 "244" => "o", "245" => "o", "246" => "o", "247" => "/", "248" => "o",
158 "249" => "u", "250" => "u", "251" => "u", "252" => "u", "253" => "y",
159 "255" => "y", "8218" => ",");
160
161
162# returns the character as a raw utf-8 character. It assumes that the
163# & and ; have been stripped off the string.
164sub getcharequiv {
165 my ($entity, $convertsymbols) = @_;
166
167 # a numeric entity
168 if ($entity =~ /^\#0*(\d+)/) {
169 my $code=$1;
170 # non-standard Microsoft breakage, as usual
171 if ($code < 0x9f) { # code page 1252 uses reserved bytes
172 if ($code == 0x91) {$code=0x2018} # 145 = single left quote
173 elsif ($code == 0x92) {$code=0x2019} # 146 = single right quote
174 elsif ($code == 0x93) {$code=0x201c} # 147 = double left quote
175 elsif ($code == 0x94) {$code=0x201d} # 148 = double right quote
176 # ...
177 }
178 return &unicode::unicode2utf8([$code]);
179 }
180
181 # a named character entity
182 if (defined $charnetosf{$entity}) {
183 return &unicode::unicode2utf8([$charnetosf{$entity}]);
184 }
185
186 # a named symbol entity
187 if ($convertsymbols && defined $symnetosf{$entity}) {
188 return &unicode::unicode2utf8([$symnetosf{$entity}]);
189 }
190
191 return "&$entity;"; # unknown character
192}
193
194# convert character entities from named equivalents to html font
195sub convertcharentities {
196 # args: the text that you want to convert
197
198 $_[0] =~ s/&([^;]+);/&getcharequiv($1,0)/gse;
199}
200
201# convert any entities from named equivalents to html font
202sub convertallentities {
203 # args: the text that you want to convert
204
205 $_[0] =~ s/&([^;]+);/&getcharequiv($1,1)/gse;
206}
207
208sub html2txt {
209 # args: the text that you want converted to ascii,
210 # and whether to strip out sgml tags
211
212 # strip out sgml tags if needed
213 $_[0] =~ s/<[^>]*>//g if $_[1];
214
215 # convert the char entities to the standard html font
216 &convertcharentities($_[0]);
217
218 # convert the html character set to a plain ascii character set
219 my $pos = 0;
220 while ($pos < length($_[0])) {
221 my $charnum = ord(substr($_[0], $pos, 1));
222 if ($charnum >= 32) { # only convert characters above #32
223 my $replacechars = " ";
224 $replacechars = $sftotxt{$charnum} if defined $sftotxt{$charnum};
225 substr($_[0], $pos, 1) = $replacechars;
226 $pos += length ($replacechars);
227
228 } else {
229 $pos ++;
230 }
231 }
232}
233
234
235# look for mime.types (eg in /etc, or apache/conf directories), or have a look
236# at <ftp://ftp.iana.org/in-notes/iana/assignments/media-types/> for defaults.
237sub guess_mime_type {
238 my ($filename) = @_;
239
240 my ($fileext) = $filename =~ /\.(\w+)$/;
241 return "unknown" unless defined $fileext;
242
243 my %mime_type = ("ai"=>"application/postscript", "aif"=>"audio/x-aiff",
244 "aifc"=>"audio/x-aiff", "aiff"=>"audio/x-aiff",
245 "au"=>"audio/basic", "avi"=>"video/x-msvideo",
246 "bcpio"=>"application/x-bcpio", "bin"=>"application/octet-stream",
247 "cdf"=>"application/x-netcdf", "class"=>"application/octet-stream",
248 "cpio"=>"application/x-cpio", "cpt"=>"application/mac-compactpro",
249 "csh"=>"application/x-csh", "dcr"=>"application/x-director",
250 "dir"=>"application/x-director", "dms"=>"application/octet-stream",
251 "doc"=>"application/msword", "dvi"=>"application/x-dvi",
252 "dxr"=>"application/x-director", "eps"=>"application/postscript",
253 "etx"=>"text/x-setext",
254 "exe"=>"application/octet-stream", "gif"=>"image/gif",
255 "gtar"=>"application/x-gtar", "hdf"=>"application/x-hdf",
256 "hqx"=>"application/mac-binhex40", "htm"=>"text/html",
257 "html"=>"text/html", "ice"=>"x-conference/x-cooltalk",
258 "ief"=>"image/ief", "jpe"=>"image/jpeg",
259 "jpeg"=>"image/jpeg", "jpg"=>"image/jpeg",
260 "kar"=>"audio/midi", "latex"=>"application/x-latex",
261 "lha"=>"application/octet-stream", "lzh"=>"application/octet-stream",
262 "man"=>"application/x-troff-man", "mcf"=>"image/vasa",
263 "me"=>"application/x-troff-me", "mid"=>"audio/midi",
264 "midi"=>"audio/midi", "mif"=>"application/x-mif",
265 "mov"=>"video/quicktime", "movie"=>"video/x-sgi-movie",
266 "mp2"=>"audio/mpeg", "mpe"=>"video/mpeg",
267 "mpeg"=>"video/mpeg", "mpg"=>"video/mpeg",
268 "mpga"=>"audio/mpeg", "ms"=>"application/x-troff-ms",
269 "nc"=>"application/x-netcdf", "oda"=>"application/oda",
270 "pbm"=>"image/x-portable-bitmap", "pdb"=>"chemical/x-pdb",
271 "pdf"=>"application/pdf", "pgm"=>"image/x-portable-graymap",
272 "png"=>"image/png", "pnm"=>"image/x-portable-anymap",
273 "ppm"=>"image/x-portable-pixmap",
274 "ppt"=>"application/vnd.ms-powerpoint",
275 "ps"=>"application/postscript", "qt"=>"video/quicktime",
276 "ra"=>"audio/x-realaudio", "ram"=>"audio/x-pn-realaudio",
277 "ras"=>"image/x-cmu-raster", "rgb"=>"image/x-rgb",
278 "roff"=>"application/x-troff", "rpm"=>"audio/x-pn-realaudio-plugin",
279 "rtf"=>"application/rtf", "rtx"=>"text/richtext",
280 "sgm"=>"text/x-sgml", "sgml"=>"text/x-sgml",
281 "sh"=>"application/x-sh", "shar"=>"application/x-shar",
282 "sit"=>"application/x-stuffit", "skd"=>"application/x-koan",
283 "skm"=>"application/x-koan", "skp"=>"application/x-koan",
284 "skt"=>"application/x-koan", "snd"=>"audio/basic",
285 "src"=>"application/x-wais-source", "sv4cpio"=>"application/x-sv4cpio",
286 "sv4crc"=>"application/x-sv4crc", "t"=>"application/x-troff",
287 "tar"=>"application/x-tar", "tcl"=>"application/x-tcl",
288 "tex"=>"application/x-tex", "texi"=>"application/x-texinfo",
289 "texinfo"=>"application/x-texinfo", "tif"=>"image/tiff",
290 "tiff"=>"image/tiff", "tr"=>"application/x-troff",
291 "tsv"=>"text/tab-separated-values", "txt"=>"text/plain",
292 "ustar"=>"application/x-ustar", "vcd"=>"application/x-cdlink",
293 "vrml"=>"x-world/x-vrml", "wav"=>"audio/x-wav",
294 "wrl"=>"x-world/x-vrml", "xbm"=>"image/x-xbitmap",
295 "xls"=>"application/vnd.ms-excel",
296 "xpm"=>"image/x-xpixmap", "xwd"=>"image/x-xwindowdump",
297 "xyz"=>"chemical/x-pdb", "zip"=>"application/zip");
298
299 return $mime_type{$fileext} if (defined $mime_type{$fileext});
300
301 return "unknown";
302}
303
304
3051;
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