source: trunk/gsdl/perllib/plugins/EMAILPlug.pm@ 2638

Last change on this file since 2638 was 2638, checked in by jrm21, 23 years ago

typo in regexp broke import... encoding type should have had [\s], not
[
s] (only broke base64 though, quoted-printable and 7bit/8bit were OK...)

  • Property svn:executable set to *
  • Property svn:keywords set to Author Date Id Revision
File size: 17.7 KB
Line 
1###########################################################################
2#
3# EMAILPlug.pm - a plugin for parsing email files
4#
5# A component of the Greenstone digital library software
6# from the New Zealand Digital Library Project at the
7# University of Waikato, New Zealand.
8#
9# Copyright (C) 1999 New Zealand Digital Library Project
10#
11# This program is free software; you can redistribute it and/or modify
12# it under the terms of the GNU General Public License as published by
13# the Free Software Foundation; either version 2 of the License, or
14# (at your option) any later version.
15#
16# This program is distributed in the hope that it will be useful,
17# but WITHOUT ANY WARRANTY; without even the implied warranty of
18# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19# GNU General Public License for more details.
20#
21# You should have received a copy of the GNU General Public License
22# along with this program; if not, write to the Free Software
23# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24#
25###########################################################################
26
27
28
29# EMAILPlug
30#
31# by Gordon Paynter ([email protected])
32#
33# Email plug reads email files. These are named with a simple
34# number (i.e. as they appear in maildir folders) or with the
35# extension .mbx (for mbox mail file format)
36#
37# Document text:
38# The document text consists of all the text
39# after the first blank line in the document.
40#
41# Metadata:
42# $Headers All the header content
43# $Subject Subject: header
44# $To To: header
45# $From From: header - this will be stored as Creator
46# $FromName Name of sender (where available)
47# $FromAddr E-mail address of sender
48# $DateText Date: header
49# $Date Date: header in GSDL format (eg: 19990924)
50#
51#
52# John McPherson - June/July 2001
53# added (basic) MIME support and quoted-printable and base64 decodings.
54# Minor fixes for names that are actually email addresses (ie <...> was lost)
55#
56# See: * RFC 822 - ARPA Internet Text Messages
57# * RFC 2045 - Multipurpose Internet Mail Extensions (MIME) -part1
58# * RFC 2046 - MIME (part 2) Media Types (and multipart messages)
59# * RFC 1806 - Content Dispositions (ie inline/attachment)
60package EMAILPlug;
61
62use SplitPlug;
63
64use sorttools;
65use util;
66
67
68# EMAILPlug is a sub-class of SplitPlug.
69
70sub BEGIN {
71 @ISA = ('SplitPlug');
72}
73
74# Create a new EMAILPlug object with which to parse a file.
75# Accomplished by creating a new BasPlug and using bless to
76# turn it into an EMAILPlug.
77
78sub new {
79 my ($class) = @_;
80 my $self = new BasPlug ("EMAILPlug", @_);
81 # make sure we don't run textcat (defaults to "auto");
82 $self->{'input_encoding'}="ascii"; # this might not be good enough...
83 return bless $self, $class;
84}
85
86sub get_default_process_exp {
87 my $self = shift (@_);
88 # mbx/email for mailbox file format, \d+ for maildir (each message is
89 # in a separate file, with a unique number for filename)
90 return q@([\\/]\d+|\.(mbx|email))$@;
91}
92
93# This plugin splits the mbox mail files at lines starting with From<sp>
94sub get_default_split_exp {
95 return q^\nFrom .*\n^;
96}
97
98
99# do plugin specific processing of doc_obj
100sub process {
101
102 my $self = shift (@_);
103 my ($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj) = @_;
104 my $outhandle = $self->{'outhandle'};
105
106 # Check that we're dealing with a valid mail file
107 return undef unless (($$textref =~ /From:/m) || ($$textref =~ /To:/m));
108
109 # slightly more strict validity check, to prevent us from matching
110 # .so.x files ...
111 return undef unless (($$textref =~ /^From /) ||
112 ($$textref =~ /^[-A-Za-z]{2,100}:/m));
113
114 print $outhandle "EMAILPlug: processing $file\n"
115 if $self->{'verbosity'} > 1;
116
117 my $cursection = $doc_obj->get_top_section();
118
119 #
120 # Parse the document's text and extract metadata
121 #
122
123 # Separate header from body of message
124 my $Headers = $$textref;
125 $Headers =~ s/\r?\n\r?\n(.*)$//s;
126 $$textref = $1;
127
128 # Unfold headers - see rfc822
129 $Headers =~ s/\r?\n[\t\ ]+/ /gs;
130 # Extract basic metadata from header
131 my @headers = ("From", "To", "Subject", "Date");
132 my %raw;
133 foreach my $name (@headers) {
134 $raw{$name} = "No $name value";
135 }
136
137 # Examine each line of the headers
138 my ($line, $name, $value);
139 my @parts;
140 foreach $line (split(/\n/, $Headers)) {
141
142 # Ignore lines with no content or which begin with whitespace
143 next unless ($line =~ /:/);
144 next if ($line =~ /^\s/);
145
146 # Find out what metadata is on this line
147 @parts = split(/:/, $line);
148 $name = shift @parts;
149# uppercase the first character according to the current locale
150 $name=~s/(.+)/\u$1/;
151 next unless $name;
152 next unless ($raw{$name});
153
154 # Find the value of that metadata
155 $value = join(":", @parts);
156 $value =~ s/^\s+//;
157 $value =~ s/\s+$//;
158
159 # Store the metadata
160 $raw{$name} = $value;
161 }
162
163 # Extract the name and e-mail address from the From metadata
164 $frommeta = $raw{"From"};
165 $frommeta =~ m/(.*)<(.*)>/;
166 my $fromnamemeta=$1;
167 my $fromaddrmeta=$2;
168 if (!defined($fromaddrmeta)) {
169 $fromaddrmeta=$frommeta;
170 }
171 $doc_obj->add_utf8_metadata ($cursection, "FromAddr", $fromaddrmeta);
172
173 if (defined($fromnameneta)) {
174 $fromnamemeta =~ s/\"//g;
175 $fromnamemeta =~ s/(.*) /$1/; # Remove trailing space
176 }
177 else {
178 $fromnamemeta = $fromaddrmeta;
179 }
180 # if name is an address
181 $fromnamemeta =~ s/<//g; $fromnamemeta =~ s/>//g;
182 $doc_obj->add_utf8_metadata ($cursection, "FromName", $fromnamemeta);
183
184 # Escape < and > in the whole From field;
185 $frommeta =~ s/</&lt;/g; $frommeta =~ s/>/&gt;/g;
186 $raw{"From"}=$frommeta;
187
188 # Process Date information
189 if ($raw{"Date"} !~ /No Date/) {
190 $raw{"DateText"} = $raw{"Date"};
191
192 # Convert the date text to internal date format
193 $value = $raw{"Date"};
194 my ($day, $month, $year) = $value =~ /(\d?\d)\s([A-Z][a-z][a-z])\s(\d\d\d?\d?)/;
195 if ($year < 100) { $year += 1900; }
196 $raw{"Date"} = &sorttools::format_date($day, $month, $year);
197
198 } else {
199 # We have not extracted a date
200 $raw{"DateText"} = "Unknown.";
201 $raw{"Date"} = "19000000";
202 }
203
204
205 # Add extracted metadata to document object
206 foreach my $name (keys %raw) {
207 $value = $raw{$name};
208 if ($value) {
209 $value = &text_into_html($value);
210 } else {
211 $value = "No $name field";
212 }
213 $doc_obj->add_utf8_metadata ($cursection, $name, $value);
214 }
215
216 my $mimetype="text/plain";
217 my $mimeinfo="";
218 # Do MIME and encoding stuff
219 if ($Headers =~ /^content\-type:\s*([\w\/\-]+)\s*\;?\s*([^\s]+)\s*$/mi)
220 {
221 $mimetype=$1;
222 $mimetype =~ tr/[A-Z]/[a-z]/;
223 $mimeinfo=$2;
224 }
225
226 if ($mimetype ne "text/plain") {
227 $$textref=text_from_mime_message($mimetype,$mimeinfo,$$textref);
228 } # end of not text/plain
229
230
231 # Add "All headers" metadata
232 $Headers = &text_into_html($Headers);
233 $Headers = "No headers" unless ($Headers =~ /\w/);
234 $doc_obj->add_utf8_metadata ($cursection, "Headers", $Headers);
235
236 # Add text to document object
237 if ($mimetype eq "text/plain") {
238 $$textref = &text_into_html($$textref);
239 }
240 $$textref = "No message" unless ($$textref =~ /\w/);
241 $doc_obj->add_utf8_text($cursection, $$textref);
242
243 return 1;
244}
245
246
247# Convert a text string into HTML.
248#
249# The HTML is going to be inserted into a GML file, so
250# we have to be careful not to use symbols like ">",
251# which ocurs frequently in email messages (and use
252# &gt instead.
253#
254# This function also turns links and email addresses into hyperlinks,
255# and replaces carriage returns with <BR> tags (and multiple carriage
256# returns with <P> tags).
257
258
259sub text_into_html {
260 my ($text) = @_;
261
262 # Convert problem characters into HTML symbols
263 $text =~ s/&/&amp;/go;
264 $text =~ s/</&lt;/go;
265 $text =~ s/>/&gt;/go;
266 $text =~ s/\"/&quot;/go;
267
268 # convert email addresses and URIs into links
269# don't markup email addresses for now
270# $text =~ s/([\w\d\.\-]+@[\w\d\.\-]+)/<a href=\"mailto:$1\">$1<\/a>/g;
271
272 # assume hostnames are \.\w\d\- only, then might have a trailing '/.*'
273 # URI can't finish with a '.'
274 $text =~ s/((http|ftp|https):\/\/[\w\d\-]+(\.[\w\d\-]+)*\/?((&amp;|\.)?[\w\d\?\=\-_\/~]+)*)/<a href=\"$1\">$1<\/a>/g;
275
276
277 # Clean up whitespace and convert \n charaters to <BR> or <P>
278 $text =~ s/ +/ /go;
279 $text =~ s/\s*$//o;
280 $text =~ s/^\s*//o;
281 $text =~ s/\n/\n<BR>/go;
282 $text =~ s/<BR>\s*<BR>/<P>/go;
283
284 return $text;
285}
286
287
288
289
290#Process a MIME message.
291# the textref we are given DOES NOT include the header.
292sub text_from_mime_message {
293 my ($mimetype,$mimeinfo,$text)=(@_);
294
295 # Check for multiparts - $mimeinfo will be a boundary
296 if ($mimetype =~ /multipart/) {
297 $boundary="";
298 if ($mimeinfo =~ /boundary="?([^\s]+?)"?\s*$/im) {
299 $boundary=$1;
300 }
301 # parts start with "--$boundary"
302 # message ends with "--$boundary--"
303 # RFC says boundary is <70 chars, [A-Za-z'()+_,-./:=?], so escape any
304 # that perl might want to interpolate.
305
306 $boundary=~s/\\/\\\\/g;
307 $boundary=~s/([\?\+\.\(\)\:\/\'])/\\$1/g;
308 my @message_parts = split("\r?\n\-\-$boundary", $text);
309 # remove first "part" and last "part" (final --)
310 shift @message_parts;
311 my $last=pop @message_parts;
312 # make sure it is only -- and whitespace
313 if ($last !~ /^\-\-\s*$/ms) {
314 print $outhandle "EMAILPlug: (warning) last part of MIME message isn't empty\n";
315 }
316 foreach my $message_part (@message_parts) {
317 # remove the leading newline left from split.
318 $message_part=~s/^\r?\n//;
319 }
320 if ($mimetype eq "multipart/alternative") {
321 # check for an HTML version first, then TEXT, otherwise use first.
322 my $part_text="";
323 foreach my $message_part (@message_parts) {
324 if ($message_part =~ m@\s*content\-type:\s*text/html@mis)
325 {
326 # Use the HTML version
327 $part_text=text_from_part($message_part);
328 $mimetype="text/html";
329 last;
330 }
331 }
332 if ($part_text eq "") { # try getting a text part instead
333 foreach my $message_part (@message_parts) {
334 if ($message_part =~ m@^content\-type:\s*text/plain@mis)
335 {
336 # Use the plain version
337 $part_text=text_from_part($message_part);
338 $mimetype="text/plain";
339 last;
340 }
341 }
342 }
343 if ($part_text eq "") { # use first part
344 $part_text=text_from_part(shift @message_parts);
345 }
346 if ($part_text eq "") { # we couldn't get anything!!!
347 # or it was an empty message...
348 # do nothing...
349 print $outhandle "EMAILPlug: no text - empty body?\n";
350 } else {
351 $text=$part_text;
352 }
353 } elsif ($mimetype eq "multipart/mixed" ||
354 $mimetype eq "multipart/digest") {
355 $text="";
356 foreach my $message_part (@message_parts) {
357 my $part_header=$message_part;
358 $part_header=~s/\r?\n\r?\n(.*)$//sg;
359 my $part_body=$1;
360 $part_header =~ s/\r?\n[\t\ ]+/ /gs; #unfold
361 my $part_content_type="";
362 my $part_content_info="";
363 if ($mimetype eq "multipart/digest") {
364 # default type - RTFRFC!!
365 $part_content_type="message/rfc822";
366 }
367 if ($part_header =~ m@^content\-type:\s*([\w+/\-]+)\s*\;?\s*([^\s]+)@mi) {
368 $part_content_type=$1; $part_content_type =~ tr/A-Z/a-z/;
369 $part_content_info=$2;
370 }
371 my $filename="";
372 if ($part_header =~ m@name=\"?([\w\.\-\\/]+)\"?@mis) {
373 $filename=$1;
374 }
375
376 # disposition - either inline or attachment.
377 # NOT CURRENTLY USED - we display all text types instead...
378 # $part_header =~ /^content\-disposition:\s*([\w+])/mis;
379
380 # add <<attachment>> to each part except the first...
381 if ($text ne "") {
382 $text.="<p><hr><strong>&lt;&lt;attachment&gt;&gt;</>";
383 # add part info header
384 $text.="<br>Type: $part_content_type<br>\n";
385 if ($filename ne "") {
386 $text.="Filename: $filename\n";
387 }
388 $text.="</strong></p>\n";
389 }
390
391 if ($part_content_type =~ m@text/@)
392 {
393 my $part_text=text_from_part($message_part);
394 if ($part_content_type !~ m@text/(ht|x)ml@) {
395 $part_text=text_into_html($part_text);
396 }
397 if ($part_text eq "") {
398 $part_text='&lt;&lt;empty message&gt;&gt;';
399 }
400 $text.=$part_text;
401 } elsif ($part_content_type =~ m@message/rfc822@) {
402 # This is a forwarded message
403 my $message_part_headers=$part_body;
404 $message_part_headers =~ s/\r?\n[\t\ ]+/ /gs; #unfold
405 $message_part_headers=~s/\r?\n\r?\n(.*)$//s;
406 my $message_part_body=$1;
407
408 my $rfc822_formatted_body=""; # put result in here
409 if ($message_part_headers =~
410 /^content\-type:\s*([\w\/\-]+)\s*\;?\s*?([^\s]+)?\s*$/ims)
411 {
412 # The message header uses MIME flags
413 my $message_content_type=$1;
414 my $message_content_info=$2;
415 if (!defined($message_content_info)) {
416 $message_content_info="";
417 }
418 $message_content_type =~ tr/A-Z/a-z/;
419 if ($message_content_type =~ /multipart/) {
420 $rfc822_formatted_body=
421 text_from_mime_message($message_content_type,
422 $message_content_info,
423 $message_part_body);
424 } else {
425 $message_part_body=text_from_part($part_body);
426 $rfc822_formatted_body=text_into_html($message_part_body);
427 }
428 } else {
429 # message doesn't use MIME flags
430 $rfc822_formatted_body=text_into_html($message_part_body);
431 }
432 # Add the returned text to the output
433 # don't put all the headers...
434 $message_part_headers =~ s/^(X\-.*|received|message\-id|return\-path):.*\n//img;
435 $text.=text_into_html($message_part_headers);
436 $text.="<p>\n";
437 $text.=$rfc822_formatted_body;
438 # end of message/rfc822
439 } elsif ($part_content_type =~ /multipart/) {
440 # recurse again
441 $tmptext=text_from_mime_message($part_content_type,
442 $part_content_info,
443 $part_body);
444 $text.=$tmptext;
445 } elsif ($text eq "") {
446 # we can't do anything with this part, but if it's the first
447 # part then make sure it is mentioned..
448
449 $text.="<p><hr><strong>&lt;&lt;attachment&gt;&gt;</>";
450 # add part info header
451 $text.="<br>Type: $part_content_type<br>\n";
452 if ($filename ne "") {
453 $text.="Filename: $filename\n";
454 }
455 $text.="</strong></p>\n";
456 }
457 } # foreach message part.
458 } else {
459 # we can't handle this multipart type (not mixed or alternative)
460 # the RFC also mentions "parallel".
461 }
462 } # end of multipart
463 return $text;
464}
465
466
467
468
469
470
471# Process a MIME part. Return "" if we can't decode it.
472sub text_from_part {
473 my $text=shift;
474 my $part_header=$text;
475 $part_header =~ s/\r?\n\r?\n(.*)$//s;
476 $text=$1; if (!defined($text)) {$text="";}
477 $part_header =~ s/\r?\n[\t ]+/ /gs; #unfold
478 $part_header =~ /content\-type:\s*([\w\/]+)/is;
479 my $type=$1; if (!defined($type)) {$type="";}
480 my $encoding="";
481 if ($part_header =~ /^content\-transfer\-encoding:\s*([^\s]+)/mis) {
482 $encoding=$1; $encoding=~tr/A-Z/a-z/;
483 }
484 # Content-Transfer-Encoding is per-part
485 if ($encoding ne "") {
486 if ($encoding =~ /quoted\-printable/) {
487 $text=qp_decode($text);
488 } elsif ($encoding =~ /base64/) {
489 $text=base64_decode($text);
490 } elsif ($encoding !~ /[78]bit/) { # leave 7/8 bit as is.
491 # rfc2045 also allows binary, which we ignore (for now).
492 # maybe this shouldn't go to stderr, but anyway...
493 print STDERR "EMAILPlug: unknown encoding: $encoding\n";
494 return "";
495 }
496 }
497
498 if ($type eq "text/html") {
499 # only get stuff between <body> tags, or <html> tags.
500 $text =~ s/^.*?<(html|HTML)[^>]*>//s;
501 $text =~ s/<\/(html|HTML)>.*$//s;
502
503 $text =~ s/^.*?<(body|BODY)[^>]*>//s;
504 $text =~ s/<\/(body|BODY)>.*$//s;
505 }
506 elsif ($type eq "text/xml") {
507 $text=~s/</&lt;/g;$text=~s/>/&gt;/g;
508 $text="<pre>\n$text\n</pre>\n";
509 }
510 return $text;
511}
512
513
514# decode quoted-printable text
515sub qp_decode {
516 my $text=shift;
517
518 my @lines=split('\n', $text);
519
520 # if a line ends with "=\s*", it is a soft line break, otherwise
521 # keep in any newline characters.
522 foreach my $line (@lines) {
523 if ($line =~ s/=\s*$//) {}
524 else {$line.="\n";}
525
526 if ($line =~ /=[0-9A-Fa-f]{2}/) { # it contains an escaped char
527 my @hexcode_segments=split('=',$line);
528 shift @hexcode_segments;
529 my @hexcodes;
530 foreach my $hexcode (@hexcode_segments) {
531 $hexcode =~ s/^(..).*$/$1/; # only need first 2 chars
532 chomp($hexcode); # just in case...
533 my $char=chr (hex "0x$hexcode");
534 $line =~ s/=$hexcode/$char/g;
535 }
536 }
537 }
538 $text= join('', @lines);
539 return $text;
540}
541
542# decode base64 text. This is fairly slow (since it's interpreted perl rather
543# than compiled XS stuff like in the ::MIME modules, but this is more portable
544# for us at least).
545# see rfc2045 for description, but basically, bits 7 and 8 are set to zero;
546# 4 bytes of encoded text become 3 bytes of binary - remove 2 highest bits
547# from each encoded byte.
548
549
550sub base64_decode {
551 my $enc_text = shift;
552# A=>0, B=>1, ..., '+'=>62, '/'=>63
553# also '=' is used for padding at the end, but we remove it anyway.
554 my $mimechars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
555# map each MIME char into it's value, for more efficient lookup.
556 my %index;
557 map { $index{$_} = index ($mimechars, $_) } (split ('', $mimechars));
558# remove all non-base64 chars. eval to get variable in transliteration...
559# also remove '=' - we'll assume (!!) that there are no errors in the encoding
560 eval "\$enc_text =~ tr|$mimechars||cd";
561 my $decoded="";
562 while (length ($enc_text)>3)
563 {
564 my $fourchars=substr($enc_text,0,4,"");
565 my @chars=(split '',$fourchars);
566 $decoded.=chr( $index{$chars[0]} << 2 | $index{$chars[1]} >> 4);
567 $decoded.=chr( ($index{$chars[1]} & 15) << 4 | $index{$chars[2]} >> 2);
568 $decoded.=chr( ($index{$chars[2]} & 3 ) << 6 | $index{$chars[3]});
569 }
570# if there are any input chars left, there are either
571# 2 encoded bytes (-> 1 raw byte) left or 3 encoded (-> 2 raw) bytes left.
572 my @chars=(split '',$enc_text);
573 if (length($enc_text)) {
574 $decoded.=chr($index{$chars[0]} << 2 | (int $index{$chars[1]} >> 4));
575 }
576 if (length($enc_text)==3) {
577 $decoded.=chr( ($index{$chars[1]} & 15) << 4 | $index{$chars[2]} >> 2);
578 }
579 return $decoded;
580}
581
582
583# Perl packages have to return true if they are run.
5841;
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