source: trunk/gsdl/perllib/plugins/EMAILPlug.pm@ 2662

Last change on this file since 2662 was 2662, checked in by jrm21, 23 years ago

oops, that's a bit stupid (of me) - changed:

if (defined($fromnameneta)) {

to:

if (defined($fromnamemeta)) {

Maybe we need more letters in the English alphabet?

  • Property svn:executable set to *
  • Property svn:keywords set to Author Date Id Revision
File size: 17.8 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 # Protect backslashes
124 $$textref =~ s@\\@\\\\@g;
125
126 # Separate header from body of message
127 my $Headers = $$textref;
128 $Headers =~ s/\r?\n\r?\n(.*)$//s;
129 $$textref = $1;
130
131 # Unfold headers - see rfc822
132 $Headers =~ s/\r?\n[\t\ ]+/ /gs;
133 # Extract basic metadata from header
134 my @headers = ("From", "To", "Subject", "Date");
135 my %raw;
136 foreach my $name (@headers) {
137 $raw{$name} = "No $name value";
138 }
139
140 # Examine each line of the headers
141 my ($line, $name, $value);
142 my @parts;
143 foreach $line (split(/\n/, $Headers)) {
144
145 # Ignore lines with no content or which begin with whitespace
146 next unless ($line =~ /:/);
147 next if ($line =~ /^\s/);
148
149 # Find out what metadata is on this line
150 @parts = split(/:/, $line);
151 $name = shift @parts;
152# uppercase the first character according to the current locale
153 $name=~s/(.+)/\u$1/;
154 next unless $name;
155 next unless ($raw{$name});
156
157 # Find the value of that metadata
158 $value = join(":", @parts);
159 $value =~ s/^\s+//;
160 $value =~ s/\s+$//;
161
162 # Store the metadata
163 $raw{$name} = $value;
164 }
165
166 # Extract the name and e-mail address from the From metadata
167 $frommeta = $raw{"From"};
168 $frommeta =~ m/(.*)<(.*)>/;
169 my $fromnamemeta=$1;
170 my $fromaddrmeta=$2;
171 if (!defined($fromaddrmeta)) {
172 $fromaddrmeta=$frommeta;
173 }
174 $doc_obj->add_utf8_metadata ($cursection, "FromAddr", $fromaddrmeta);
175
176 if (defined($fromnamemeta)) {
177 $fromnamemeta =~ s/\"//g;
178 $fromnamemeta =~ s/(.*) /$1/; # Remove trailing space
179 }
180 else {
181 $fromnamemeta = $fromaddrmeta;
182 }
183 # if name is an address
184 $fromnamemeta =~ s/<//g; $fromnamemeta =~ s/>//g;
185 $doc_obj->add_utf8_metadata ($cursection, "FromName", $fromnamemeta);
186
187 # Escape < and > in the whole From field;
188 $frommeta =~ s/</&lt;/g; $frommeta =~ s/>/&gt;/g;
189 $raw{"From"}=$frommeta;
190
191 # Process Date information
192 if ($raw{"Date"} !~ /No Date/) {
193 $raw{"DateText"} = $raw{"Date"};
194
195 # Convert the date text to internal date format
196 $value = $raw{"Date"};
197 my ($day, $month, $year) = $value =~ /(\d?\d)\s([A-Z][a-z][a-z])\s(\d\d\d?\d?)/;
198 if ($year < 100) { $year += 1900; }
199 $raw{"Date"} = &sorttools::format_date($day, $month, $year);
200
201 } else {
202 # We have not extracted a date
203 $raw{"DateText"} = "Unknown.";
204 $raw{"Date"} = "19000000";
205 }
206
207
208 # Add extracted metadata to document object
209 foreach my $name (keys %raw) {
210 $value = $raw{$name};
211 if ($value) {
212 $value = &text_into_html($value);
213 } else {
214 $value = "No $name field";
215 }
216 $doc_obj->add_utf8_metadata ($cursection, $name, $value);
217 }
218
219 my $mimetype="text/plain";
220 my $mimeinfo="";
221 # Do MIME and encoding stuff
222 if ($Headers =~ /^content\-type:\s*([\w\/\-]+)\s*\;?\s*([^\s]+)\s*$/mi)
223 {
224 $mimetype=$1;
225 $mimetype =~ tr/[A-Z]/[a-z]/;
226 $mimeinfo=$2;
227 }
228
229 if ($mimetype ne "text/plain") {
230 $$textref=text_from_mime_message($mimetype,$mimeinfo,$$textref);
231 } # end of not text/plain
232
233
234 # Add "All headers" metadata
235 $Headers = &text_into_html($Headers);
236 $Headers = "No headers" unless ($Headers =~ /\w/);
237 $doc_obj->add_utf8_metadata ($cursection, "Headers", $Headers);
238
239 # Add text to document object
240 if ($mimetype eq "text/plain") {
241 $$textref = &text_into_html($$textref);
242 }
243 $$textref = "No message" unless ($$textref =~ /\w/);
244 $doc_obj->add_utf8_text($cursection, $$textref);
245
246 return 1;
247}
248
249
250# Convert a text string into HTML.
251#
252# The HTML is going to be inserted into a GML file, so
253# we have to be careful not to use symbols like ">",
254# which ocurs frequently in email messages (and use
255# &gt instead.
256#
257# This function also turns links and email addresses into hyperlinks,
258# and replaces carriage returns with <BR> tags (and multiple carriage
259# returns with <P> tags).
260
261
262sub text_into_html {
263 my ($text) = @_;
264
265 # Convert problem characters into HTML symbols
266 $text =~ s/&/&amp;/go;
267 $text =~ s/</&lt;/go;
268 $text =~ s/>/&gt;/go;
269 $text =~ s/\"/&quot;/go;
270
271 # convert email addresses and URIs into links
272# don't markup email addresses for now
273# $text =~ s/([\w\d\.\-]+@[\w\d\.\-]+)/<a href=\"mailto:$1\">$1<\/a>/g;
274
275 # assume hostnames are \.\w\d\- only, then might have a trailing '/.*'
276 # URI can't finish with a '.'
277 $text =~ s/((http|ftp|https):\/\/[\w\d\-]+(\.[\w\d\-]+)*\/?((&amp;|\.)?[\w\d\?\=\-_\/~]+)*)/<a href=\"$1\">$1<\/a>/g;
278
279
280 # Clean up whitespace and convert \n charaters to <BR> or <P>
281 $text =~ s/ +/ /go;
282 $text =~ s/\s*$//o;
283 $text =~ s/^\s*//o;
284 $text =~ s/\n/\n<BR>/go;
285 $text =~ s/<BR>\s*<BR>/<P>/go;
286
287 return $text;
288}
289
290
291
292
293#Process a MIME message.
294# the textref we are given DOES NOT include the header.
295sub text_from_mime_message {
296 my ($mimetype,$mimeinfo,$text)=(@_);
297
298 # Check for multiparts - $mimeinfo will be a boundary
299 if ($mimetype =~ /multipart/) {
300 $boundary="";
301 if ($mimeinfo =~ /boundary="?([^\s]+?)"?\s*$/im) {
302 $boundary=$1;
303 }
304 # parts start with "--$boundary"
305 # message ends with "--$boundary--"
306 # RFC says boundary is <70 chars, [A-Za-z'()+_,-./:=?], so escape any
307 # that perl might want to interpolate.
308
309 $boundary=~s/\\/\\\\/g;
310 $boundary=~s/([\?\+\.\(\)\:\/\'])/\\$1/g;
311 my @message_parts = split("\r?\n\-\-$boundary", $text);
312 # remove first "part" and last "part" (final --)
313 shift @message_parts;
314 my $last=pop @message_parts;
315 # make sure it is only -- and whitespace
316 if ($last !~ /^\-\-\s*$/ms) {
317 print $outhandle "EMAILPlug: (warning) last part of MIME message isn't empty\n";
318 }
319 foreach my $message_part (@message_parts) {
320 # remove the leading newline left from split.
321 $message_part=~s/^\r?\n//;
322 }
323 if ($mimetype eq "multipart/alternative") {
324 # check for an HTML version first, then TEXT, otherwise use first.
325 my $part_text="";
326 foreach my $message_part (@message_parts) {
327 if ($message_part =~ m@\s*content\-type:\s*text/html@mis)
328 {
329 # Use the HTML version
330 $part_text=text_from_part($message_part);
331 $mimetype="text/html";
332 last;
333 }
334 }
335 if ($part_text eq "") { # try getting a text part instead
336 foreach my $message_part (@message_parts) {
337 if ($message_part =~ m@^content\-type:\s*text/plain@mis)
338 {
339 # Use the plain version
340 $part_text=text_from_part($message_part);
341 $mimetype="text/plain";
342 last;
343 }
344 }
345 }
346 if ($part_text eq "") { # use first part
347 $part_text=text_from_part(shift @message_parts);
348 }
349 if ($part_text eq "") { # we couldn't get anything!!!
350 # or it was an empty message...
351 # do nothing...
352 print $outhandle "EMAILPlug: no text - empty body?\n";
353 } else {
354 $text=$part_text;
355 }
356 } elsif ($mimetype =~ m@multipart/(mixed|digest|related)@) {
357 $text="";
358 foreach my $message_part (@message_parts) {
359 my $part_header=$message_part;
360 $part_header=~s/\r?\n\r?\n(.*)$//sg;
361 my $part_body=$1;
362 $part_header =~ s/\r?\n[\t\ ]+/ /gs; #unfold
363 my $part_content_type="";
364 my $part_content_info="";
365 if ($mimetype eq "multipart/digest") {
366 # default type - RTFRFC!!
367 $part_content_type="message/rfc822";
368 }
369 if ($part_header =~ m@^content\-type:\s*([\w+/\-]+)\s*\;?\s*([^\s]+)@mi) {
370 $part_content_type=$1; $part_content_type =~ tr/A-Z/a-z/;
371 $part_content_info=$2;
372 }
373 my $filename="";
374 if ($part_header =~ m@name=\"?([\w\.\-\\/]+)\"?@mis) {
375 $filename=$1;
376 }
377
378 # disposition - either inline or attachment.
379 # NOT CURRENTLY USED - we display all text types instead...
380 # $part_header =~ /^content\-disposition:\s*([\w+])/mis;
381
382 # add <<attachment>> to each part except the first...
383 if ($text ne "") {
384 $text.="<p><hr><strong>&lt;&lt;attachment&gt;&gt;</>";
385 # add part info header
386 $text.="<br>Type: $part_content_type<br>\n";
387 if ($filename ne "") {
388 $text.="Filename: $filename\n";
389 }
390 $text.="</strong></p>\n";
391 }
392
393 if ($part_content_type =~ m@text/@)
394 {
395 my $part_text=text_from_part($message_part);
396 if ($part_content_type !~ m@text/(ht|x)ml@) {
397 $part_text=text_into_html($part_text);
398 }
399 if ($part_text eq "") {
400 $part_text='&lt;&lt;empty message&gt;&gt;';
401 }
402 $text.=$part_text;
403 } elsif ($part_content_type =~ m@message/rfc822@) {
404 # This is a forwarded message
405 my $message_part_headers=$part_body;
406 $message_part_headers =~ s/\r?\n[\t\ ]+/ /gs; #unfold
407 $message_part_headers=~s/\r?\n\r?\n(.*)$//s;
408 my $message_part_body=$1;
409
410 my $rfc822_formatted_body=""; # put result in here
411 if ($message_part_headers =~
412 /^content\-type:\s*([\w\/\-]+)\s*\;?\s*?([^\s]+)?\s*$/ims)
413 {
414 # The message header uses MIME flags
415 my $message_content_type=$1;
416 my $message_content_info=$2;
417 if (!defined($message_content_info)) {
418 $message_content_info="";
419 }
420 $message_content_type =~ tr/A-Z/a-z/;
421 if ($message_content_type =~ /multipart/) {
422 $rfc822_formatted_body=
423 text_from_mime_message($message_content_type,
424 $message_content_info,
425 $message_part_body);
426 } else {
427 $message_part_body=text_from_part($part_body);
428 $rfc822_formatted_body=text_into_html($message_part_body);
429 }
430 } else {
431 # message doesn't use MIME flags
432 $rfc822_formatted_body=text_into_html($message_part_body);
433 }
434 # Add the returned text to the output
435 # don't put all the headers...
436 $message_part_headers =~ s/^(X\-.*|received|message\-id|return\-path):.*\n//img;
437 $text.=text_into_html($message_part_headers);
438 $text.="<p>\n";
439 $text.=$rfc822_formatted_body;
440 # end of message/rfc822
441 } elsif ($part_content_type =~ /multipart/) {
442 # recurse again
443 $tmptext=text_from_mime_message($part_content_type,
444 $part_content_info,
445 $part_body);
446 $text.=$tmptext;
447 } elsif ($text eq "") {
448 # we can't do anything with this part, but if it's the first
449 # part then make sure it is mentioned..
450
451 $text.="<p><hr><strong>&lt;&lt;attachment&gt;&gt;</>";
452 # add part info header
453 $text.="<br>Type: $part_content_type<br>\n";
454 if ($filename ne "") {
455 $text.="Filename: $filename\n";
456 }
457 $text.="</strong></p>\n";
458 }
459 } # foreach message part.
460 } else {
461 # we can't handle this multipart type (not mixed or alternative)
462 # the RFC also mentions "parallel".
463 }
464 } # end of multipart
465 return $text;
466}
467
468
469
470
471
472
473# Process a MIME part. Return "" if we can't decode it.
474sub text_from_part {
475 my $text=shift;
476 my $part_header=$text;
477 $part_header =~ s/\r?\n\r?\n(.*)$//s;
478 $text=$1; if (!defined($text)) {$text="";}
479 $part_header =~ s/\r?\n[\t ]+/ /gs; #unfold
480 $part_header =~ /content\-type:\s*([\w\/]+)/is;
481 my $type=$1; if (!defined($type)) {$type="";}
482 my $encoding="";
483 if ($part_header =~ /^content\-transfer\-encoding:\s*([^\s]+)/mis) {
484 $encoding=$1; $encoding=~tr/A-Z/a-z/;
485 }
486 # Content-Transfer-Encoding is per-part
487 if ($encoding ne "") {
488 if ($encoding =~ /quoted\-printable/) {
489 $text=qp_decode($text);
490 } elsif ($encoding =~ /base64/) {
491 $text=base64_decode($text);
492 } elsif ($encoding !~ /[78]bit/) { # leave 7/8 bit as is.
493 # rfc2045 also allows binary, which we ignore (for now).
494 # maybe this shouldn't go to stderr, but anyway...
495 print STDERR "EMAILPlug: unknown encoding: $encoding\n";
496 return "";
497 }
498 }
499
500 if ($type eq "text/html") {
501 # only get stuff between <body> tags, or <html> tags.
502 $text =~ s/^.*?<(html|HTML)[^>]*>//s;
503 $text =~ s/<\/(html|HTML)>.*$//s;
504
505 $text =~ s/^.*?<(body|BODY)[^>]*>//s;
506 $text =~ s/<\/(body|BODY)>.*$//s;
507 }
508 elsif ($type eq "text/xml") {
509 $text=~s/</&lt;/g;$text=~s/>/&gt;/g;
510 $text="<pre>\n$text\n</pre>\n";
511 }
512 return $text;
513}
514
515
516# decode quoted-printable text
517sub qp_decode {
518 my $text=shift;
519
520 my @lines=split('\n', $text);
521
522 # if a line ends with "=\s*", it is a soft line break, otherwise
523 # keep in any newline characters.
524 foreach my $line (@lines) {
525 if ($line =~ s/=\s*$//) {}
526 else {$line.="\n";}
527
528 if ($line =~ /=[0-9A-Fa-f]{2}/) { # it contains an escaped char
529 my @hexcode_segments=split('=',$line);
530 shift @hexcode_segments;
531 my @hexcodes;
532 foreach my $hexcode (@hexcode_segments) {
533 $hexcode =~ s/^(..).*$/$1/; # only need first 2 chars
534 chomp($hexcode); # just in case...
535 my $char=chr (hex "0x$hexcode");
536 $line =~ s/=$hexcode/$char/g;
537 }
538 }
539 }
540 $text= join('', @lines);
541 return $text;
542}
543
544# decode base64 text. This is fairly slow (since it's interpreted perl rather
545# than compiled XS stuff like in the ::MIME modules, but this is more portable
546# for us at least).
547# see rfc2045 for description, but basically, bits 7 and 8 are set to zero;
548# 4 bytes of encoded text become 3 bytes of binary - remove 2 highest bits
549# from each encoded byte.
550
551
552sub base64_decode {
553 my $enc_text = shift;
554# A=>0, B=>1, ..., '+'=>62, '/'=>63
555# also '=' is used for padding at the end, but we remove it anyway.
556 my $mimechars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
557# map each MIME char into it's value, for more efficient lookup.
558 my %index;
559 map { $index{$_} = index ($mimechars, $_) } (split ('', $mimechars));
560# remove all non-base64 chars. eval to get variable in transliteration...
561# also remove '=' - we'll assume (!!) that there are no errors in the encoding
562 eval "\$enc_text =~ tr|$mimechars||cd";
563 my $decoded="";
564 while (length ($enc_text)>3)
565 {
566 my $fourchars=substr($enc_text,0,4,"");
567 my @chars=(split '',$fourchars);
568 $decoded.=chr( $index{$chars[0]} << 2 | $index{$chars[1]} >> 4);
569 $decoded.=chr( ($index{$chars[1]} & 15) << 4 | $index{$chars[2]} >> 2);
570 $decoded.=chr( ($index{$chars[2]} & 3 ) << 6 | $index{$chars[3]});
571 }
572# if there are any input chars left, there are either
573# 2 encoded bytes (-> 1 raw byte) left or 3 encoded (-> 2 raw) bytes left.
574 my @chars=(split '',$enc_text);
575 if (length($enc_text)) {
576 $decoded.=chr($index{$chars[0]} << 2 | (int $index{$chars[1]} >> 4));
577 }
578 if (length($enc_text)==3) {
579 $decoded.=chr( ($index{$chars[1]} & 15) << 4 | $index{$chars[2]} >> 2);
580 }
581 return $decoded;
582}
583
584
585# Perl packages have to return true if they are run.
5861;
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