source: main/trunk/greenstone2/perllib/downloaders/WgetDownload.pm@ 31874

Last change on this file since 31874 was 31874, checked in by ak19, 7 years ago

Fix ahead of switching over to proxy env vars on Windows. This fix sets proxy settings for Windows downloads, so that http_proxy and https_proxy flags can both be set.

  • Property svn:keywords set to Author Date Id Revision
File size: 19.5 KB
Line 
1###########################################################################
2#
3# WgetDownload.pm -- Download base module that handles calling Wget
4# A component of the Greenstone digital library software
5# from the New Zealand Digital Library Project at the
6# University of Waikato, New Zealand.
7#
8# Copyright (C) 2006 New Zealand Digital Library Project
9#
10# This program is free software; you can redistribute it and/or modify
11# it under the terms of the GNU General Public License as published by
12# the Free Software Foundation; either version 2 of the License, or
13# (at your option) any later version.
14#
15# This program is distributed in the hope that it will be useful,
16# but WITHOUT ANY WARRANTY; without even the implied warranty of
17# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18# GNU General Public License for more details.
19#
20# You should have received a copy of the GNU General Public License
21# along with this program; if not, write to the Free Software
22# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23#
24###########################################################################
25
26package WgetDownload;
27
28eval {require bytes};
29
30# suppress the annoying "subroutine redefined" warning that various
31# plugins cause under perl 5.6
32$SIG{__WARN__} = sub {warn($_[0]) unless ($_[0] =~ /Subroutine\s+\S+\sredefined/)};
33
34use BaseDownload;
35use strict;
36use Cwd;
37use util;
38use IPC::Open3;
39use IO::Select;
40use IO::Socket;
41
42
43sub BEGIN {
44 @WgetDownload::ISA = ('BaseDownload');
45}
46
47my $arguments =
48 [ { 'name' => "proxy_on",
49 'desc' => "{WgetDownload.proxy_on}",
50 'type' => "flag",
51 'reqd' => "no",
52 'hiddengli' => "yes"},
53 { 'name' => "proxy_host",
54 'desc' => "{WgetDownload.proxy_host}",
55 'type' => "string",
56 'reqd' => "no",
57 'hiddengli' => "yes"},
58 { 'name' => "proxy_port",
59 'desc' => "{WgetDownload.proxy_port}",
60 'type' => "string",
61 'reqd' => "no",
62 'hiddengli' => "yes"},
63 { 'name' => "user_name",
64 'desc' => "{WgetDownload.user_name}",
65 'type' => "string",
66 'reqd' => "no",
67 'hiddengli' => "yes"},
68 { 'name' => "user_password",
69 'desc' => "{WgetDownload.user_password}",
70 'type' => "string",
71 'reqd' => "no",
72 'hiddengli' => "yes"},
73 { 'name' => "no_check_certificate",
74 'desc' => "{WgetDownload.no_check_certificate}",
75 'type' => "flag",
76 'reqd' => "no",
77 'hiddengli' => "yes"}
78 ];
79
80my $options = { 'name' => "WgetDownload",
81 'desc' => "{WgetDownload.desc}",
82 'abstract' => "yes",
83 'inherits' => "yes",
84 'args' => $arguments };
85
86
87# Declaring file global variables related to the wget child process so that
88# the termination signal handler for SIGTERM can close the streams and tidy
89# up before ending the child process.
90my $childpid;
91my ($chld_out, $chld_in);
92my ($serverSocket, $read_set);
93
94# The port this script's server socket will be listening on, to handle
95# incoming signals from GLI to terminate wget. This is also file global,
96# since OAIDownload.pm will make several calls on wget using the same
97# instance of this script and we want to reuse whatever port GLI gave us.
98my $port;
99
100# When this script is called from the command line, this handler will be called
101# if this process is killed or abruptly ends due to receiving one of the
102# terminating signals that this handler is registered to deal with.
103sub abrupt_end_handler {
104 my $termination_signal = shift (@_);
105
106 if(defined $childpid) {
107 close($chld_out);
108 close($chld_in);
109
110 print STDOUT "Received termination signal: $termination_signal\n";
111
112 # Send TERM signal to child process to terminate it. Sending the INT signal doesn't work
113 # See http://perldoc.perl.org/perlipc.html#Signals
114 # Warning on using kill at http://perldoc.perl.org/perlfork.html
115 kill("TERM", $childpid);
116
117 # If the SIGTERM sent on Linux calls this handler, we want to make
118 # sure any socket connection is closed.
119 # Otherwise sockets are only used when this script is run from GLI
120 # in which case the handlers don't really get called.
121 if(defined $serverSocket) {
122 $read_set->remove($serverSocket) if defined $read_set;
123 close($serverSocket);
124 }
125 }
126
127 exit(0);
128}
129
130# Registering a handler for when termination signals SIGINT and SIGTERM are received to stop
131# the wget child process. SIGTERM--generated by Java's Process.destroy()--is the default kill
132# signal (kill -15) on Linux, while SIGINT is generated upon Ctrl-C (also on Windows).
133# Note that SIGKILL can't be handled as the handler won't get called for it. More information:
134# http://affy.blogspot.com/p5be/ch13.htm
135# http://perldoc.perl.org/perlipc.html#Signals
136$SIG{'INT'} = \&abrupt_end_handler;
137$SIG{'TERM'} = \&abrupt_end_handler;
138
139sub new {
140 my ($class) = shift (@_);
141 my ($getlist,$inputargs,$hashArgOptLists) = @_;
142 push(@$getlist, $class);
143
144 push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
145 push(@{$hashArgOptLists->{"OptList"}},$options);
146
147 my $self = new BaseDownload($getlist,$inputargs,$hashArgOptLists);
148
149 # the wget binary is dependent on the gnomelib_env (particularly lib/libiconv2.dylib) being set, particularly on Mac Lions (android too?)
150 &util::set_gnomelib_env(); # this will set the gnomelib env once for each subshell launched, by first checking if GEXTGNOME is not already set
151
152 return bless $self, $class;
153}
154
155sub checkWgetSetup
156{
157 my ($self,$blnGliCall) = @_;
158 #TODO: proxy detection??
159
160 if((!$blnGliCall) && $self->{'proxy_on'})
161 {
162 &checkProxySetup($self);
163 }
164 &checkURL($self);
165}
166
167sub getWgetOptions
168{
169 my ($self) = @_;
170 my $strOptions = "";
171
172 # If http_proxy ENV VARS are not set, but proxy Perl vars are set, then we're on Windows
173 # and need to use the proxy vars as flags to wget
174 # If http_proxy Env Vars are set, then we're on Linux, wget will use the http(s) proxy
175 # env vars and we shouldn't be passing any proxy perl vars as flags
176
177 # Truth in Perl: https://home.ubalt.edu/abento/452/perl/perltruth.html
178 # http://www.perlmonks.org/?node=what%20is%20true%20and%20false%20in%20Perl%3F
179
180 if (!$ENV{'http_proxy'} && !$ENV{'https_proxy'}) {
181 if ($self->{'proxy_on'} && $self->{'proxy_host'} && $self->{'proxy_port'})
182 {
183 $strOptions .= " -e https_proxy=$self->{'proxy_host'}:$self->{'proxy_port'} ";
184 $strOptions .= " -e http_proxy=$self->{'proxy_host'}:$self->{'proxy_port'} ";
185
186 if ($self->{'user_name'} && $self->{'user_password'})
187 {
188 $strOptions .= "--proxy-user=$self->{'user_name'}"." --proxy-passwd=$self->{'user_password'}";
189 }
190 }
191
192 if ($self->{'proxy_on'}) {
193 $strOptions .= " --proxy ";
194 }
195 }
196
197 if($self->{'no_check_certificate'}) { #&& $self->{'url'} =~ m/^https\:/) { # URL may be http that gets redirected to https, so if no_check_certificate is on, turn it on even if URL is http
198
199 $strOptions .= " --no-check-certificate ";
200 }
201
202 return $strOptions;
203}
204
205# Checking for proxy setup: proxy server, proxy port, proxy username and password.
206sub checkProxySetup
207{
208 my ($self) = @_;
209 ($self->{'proxy_on'}) || &error("checkProxySetup","The proxy is not on? How could that be happening?");
210 # Setup .wgetrc by using $self->{'proxy_host'} and $self->{'proxy_port'}
211 # Test if the connection is successful. If the connection wasn't successful then ask user to supply username and password.
212
213}
214
215# Returns true if the wget status needs to be monitored through sockets
216# (if a socket is used to communicate with the Java program on when to
217# terminate wget). True if we are running gli, or if the particular type
218# of WgetDownload is *not* OAIDownload (in that case, the original way of
219# terminating the perl script from Java terminated wget as well).
220sub dealingWithSockets() {
221 my ($self) = @_;
222 return (defined $self->{'gli'} && $self->{'gli'} && !defined $port && ref($self) ne "OAIDownload");
223 # use ref($self) to find the classname of an object
224}
225
226
227sub useWget
228{
229 #local $| = 1; # autoflush stdout buffer
230 #print STDOUT "*** Start of subroutine useWget in $0\n";
231
232 my ($self, $cmdWget,$blnShow, $working_dir) = @_;
233
234 my ($strReadIn,$strLine,$command);
235 $strReadIn = "" unless defined $strReadIn;
236
237 my $current_dir = cwd();
238 my $changed_dir = 0;
239 if (defined $working_dir && -e $working_dir) {
240 chdir "$working_dir";
241 $changed_dir = 1;
242 }
243
244 # When we are running this script through GLI, the SIGTERM signal handler
245 # won't get called on Windows when wget is to be prematurely terminated.
246 # Instead, when wget has to be terminated in the middle of execution, GLI will
247 # connect to a serverSocket here to communicate when it's time to stop wget.
248 if($self->dealingWithSockets()) {
249
250 $port = <STDIN>; # gets a port on localhost that's not yet in use
251 chomp($port);
252
253 $serverSocket = IO::Socket::INET->new( Proto => 'tcp',
254 LocalPort => $port,
255 Listen => 1,
256 Reuse => 1);
257
258 die "can't setup server" unless $serverSocket;
259 #print STDOUT "[Serversocket $0 accepting clients at port $port]\n";
260
261 $read_set = new IO::Select(); # create handle set for reading
262 $read_set->add($serverSocket); # add the main socket to the set
263 }
264
265 my $wget_file_path = &FileUtils::filenameConcatenate($ENV{'GSDLHOME'}, "bin", $ENV{'GSDLOS'}, "wget");
266 $command = "\"$wget_file_path\" $cmdWget";
267 #print STDOUT "Command is: $command\n"; # displayed in GLI output
268 #print STDERR "Command is: $command\n"; # goes into ServerInfoDialog
269
270 # Wget's output needs to be monitored to find out when it has naturally terminated.
271 # Wget's output is sent to its STDERR so we can't use open2 without doing 2>&1.
272 # On linux, 2>&1 launches a subshell which then launches wget, meaning that killing
273 # the childpid does not kill wget on Linux but the subshell that launched it instead.
274 # Therefore, we use open3. Though the child process wget sends output only to its stdout,
275 # using open3 says chld_err is undefined and the output of wget only comes in chld_out(!)
276 # However that may be, it works with open3. But to avoid the confusion of managing and
277 # closing an extra unused handle, a single handle is used instead for both the child's
278 # stderr and stdout.
279 # See http://blog.0x1fff.com/2009/09/howto-execute-system-commands-in-perl.html
280 # for why this is the right thing to do.
281
282 # Both open2 and open3 don't return on failure, but raise an exception. The handling
283 # of the exception is described on p.568 of the Perl Cookbook
284 eval {
285 $childpid = open3($chld_in, $chld_out, $chld_out, $command);
286 };
287 if ($@) {
288 if($@ =~ m/^open3/) {
289 die "open3 failed in $0: $!\n$@\n";
290 }
291 die "Tried to launch open3 in $0, got unexpected exception: $@";
292 }
293
294 my $loop = 1;
295 while($loop)
296 {
297 if (defined(my $strLine=<$chld_out>)) { # we're reading in from child process' stdout
298 if($blnShow) {
299 print STDERR "$strLine\n";
300 }
301 $strReadIn .= $strLine;
302 }
303 else { # wget finished, terminate naturally
304 #print STDOUT "\nPerl: open2 command, input stream closed. Wget terminated naturally.\n";
305 close($chld_in);
306 close($chld_out);
307 waitpid $childpid, 0;
308 $loop = 0;
309
310 $childpid = undef;
311 if(defined $port) {
312 $read_set->remove($serverSocket);
313 close($serverSocket);
314 }
315 }
316
317 # if we run this script from the command-line (as opposed to from GLI),
318 # then we're not working with sockets and can therefore can skip the next bits
319 next unless(defined $port);
320
321 # http://www.perlfect.com/articles/select.shtml
322 # "multiplex between several filehandles within a single thread of control,
323 # thus creating the effect of parallelism in the handling of I/O."
324 my @rh_set = $read_set->can_read(0.002); # every 2 ms check if there's a client socket connecting
325
326 # take all readable handles in turn
327 foreach my $rh (@rh_set) {
328 if($rh == $serverSocket) {
329 my $client = $rh->accept();
330 #$client->autoflush(1); # autoflush output buffer - don't put this back in: output split irregularly over lines
331 print $client "Talked to ServerSocket (port $port). Connection accepted\n";
332
333 # Read from the client (getting rid of the trailing newline)
334 # Has the client sent the <<STOP>> signal?
335 my $signal = <$client>;
336 chomp($signal);
337 if($signal eq "<<STOP>>") {
338 print $client "Perl received STOP signal (on port $port): stopping wget\n";
339 $loop = 0; # out of outer while loop
340 $self->{'forced_quit'} = 1; # subclasses need to know we're quitting
341
342 # Sometimes the wget process takes some time to start up. If the STOP signal
343 # was sent, don't try to terminate the process until we know it is running.
344 # Otherwise wget may start running after we tried to kill it. Wait 5 seconds
345 # for it to start up, checking for whether it is running in order to kill it.
346 for(my $seconds = 1; $seconds <= 5; $seconds++) {
347 if(kill(0, $childpid)) {
348 # If kill(0, $childpid) returns true, then the process is running
349 # and we need to kill it.
350 close($chld_in);
351 close($chld_out);
352 kill("TERM", $childpid);
353
354 $childpid = undef;
355
356 # Stop monitoring the read_handle and close the serverSocket
357 # (the Java end will close the client socket that Java opened)
358 $read_set->remove($rh); #$read_set->remove($serverSocket);
359 close($rh); #close($serverSocket);
360 print $client "Perl terminated wget and is about to exit\n";
361 last; # out of inner for loop
362 }
363 else { # the process may just be starting up, wait
364 sleep(1);
365 }
366 }
367 last; # out of foreach loop
368 }
369 }
370 }
371 }
372
373 if ($changed_dir) {
374 chdir $current_dir;
375 }
376
377 return $strReadIn;
378}
379
380
381sub useWgetMonitored
382{
383 #local $| = 1; # autoflush stdout buffer
384 #print STDOUT "*** Start of subroutine useWgetMonitored in $0\n";
385
386 my ($self, $cmdWget,$blnShow, $working_dir) = @_;
387
388
389 my $current_dir = cwd();
390 my $changed_dir = 0;
391 if (defined $working_dir && -e $working_dir) {
392 chdir "$working_dir";
393 $changed_dir = 1;
394 }
395
396 # When we are running this script through GLI, the SIGTERM signal handler
397 # won't get called on Windows when wget is to be prematurely terminated.
398 # Instead, when wget has to be terminated in the middle of execution, GLI will
399 # connect to a serverSocket here to communicate when it's time to stop wget.
400 if($self->dealingWithSockets()) {
401
402 $port = <STDIN>; # gets a port on localhost that's not yet in use
403 chomp($port);
404
405 $serverSocket = IO::Socket::INET->new( Proto => 'tcp',
406 LocalPort => $port,
407 Listen => 1,
408 Reuse => 1);
409
410 die "can't setup server" unless $serverSocket;
411 #print STDOUT "[Serversocket $0 accepting clients at port $port]\n";
412
413 $read_set = new IO::Select(); # create handle set for reading
414 $read_set->add($serverSocket); # add the main socket to the set
415 }
416
417 my $wget_file_path = &FileUtils::filenameConcatenate($ENV{'GSDLHOME'}, "bin", $ENV{'GSDLOS'}, "wget");
418 my $command = "\"$wget_file_path\" $cmdWget";
419 #print STDOUT "Command is: $command\n";
420
421 eval { # see p.568 of Perl Cookbook
422 $childpid = open3($chld_in, $chld_out, $chld_out, $command);
423 };
424 if ($@) {
425 if($@ =~ m/^open3/) {
426 die "open3 failed in $0: $!\n$@\n";
427 }
428 die "Tried to launch open3 in $0, got unexpected exception: $@";
429 }
430
431 my $full_text = "";
432 my $error_text = "";
433 my @follow_list = ();
434 my $line;
435
436 my $loop = 1;
437 while($loop)
438 {
439 if (defined($line=<$chld_out>)) { # we're reading in from child process' stdout
440 if((defined $blnShow) && $blnShow)
441 {
442 print STDERR "$line";
443 }
444
445 if ($line =~ m/^Location:\s*(.*?)\s*\[following\]\s*$/i) {
446 my $follow_url = $1;
447 push(@follow_list,$follow_url);
448 }
449
450 if ($line =~ m/ERROR\s+\d+/) {
451 $error_text .= $line;
452 }
453
454 $full_text .= $line;
455 }
456 else { # wget finished, terminate naturally
457 #print STDERR "\nPerl: open2 command, input stream closed. Wget terminated naturally.\n";
458 close($chld_in);
459 close($chld_out);
460 # Program terminates only when the following line is included
461 # http://perldoc.perl.org/IPC/Open2.html explains why this is necessary
462 # it prevents the child from turning into a "zombie process".
463 # While the wget process terminates without it, this perl script does not:
464 # the DOS prompt is not returned without it.
465 waitpid $childpid, 0;
466 $loop = 0;
467
468 $childpid = undef;
469 if(defined $port) {
470 $read_set->remove($serverSocket);
471 close($serverSocket);
472 }
473 }
474
475 # if we run this script from the command-line (as opposed to from GLI),
476 # then we're not working with sockets and can therefore can skip the next bits
477 next unless(defined $port);
478
479 # http://www.perlfect.com/articles/select.shtml
480 # "multiplex between several filehandles within a single thread of control,
481 # thus creating the effect of parallelism in the handling of I/O."
482 my @rh_set = $read_set->can_read(0.002); # every 2 ms check if there's a client socket connecting
483
484 # take all readable handles in turn
485 foreach my $rh (@rh_set) {
486 if($rh == $serverSocket) {
487 my $client = $rh->accept();
488 #$client->autoflush(1); # autoflush output buffer - don't put this back in: splits output irregularly over multilines
489 print $client "Talked to ServerSocket (port $port). Connection accepted\n";
490
491 # Read from the client (getting rid of trailing newline)
492 # Has the client sent the <<STOP>> signal?
493 my $signal = <$client>;
494 chomp($signal);
495 if($signal eq "<<STOP>>") {
496 print $client "Perl received STOP signal (on port $port): stopping wget\n";
497 $loop = 0; # out of outer while loop
498 $self->{'forced_quit'} = 1; # subclasses need to know we're quitting
499
500 # Sometimes the wget process takes some time to start up. If the STOP signal
501 # was sent, don't try to terminate the process until we know it is running.
502 # Otherwise wget may start running after we tried to kill it. Wait 5 seconds
503 # for it to start up, checking for whether it is running in order to kill it.
504 for(my $seconds = 1; $seconds <= 5; $seconds++) {
505 if(kill(0, $childpid)) {
506 # If kill(0, $childpid) returns true, then the process is running
507 # and we need to kill it.
508 close($chld_in);
509 close($chld_out);
510 kill("TERM", $childpid);
511
512 $childpid = undef;
513
514 # Stop monitoring the read_handle and close the serverSocket
515 # (the Java end will close the client socket that Java opened)
516 $read_set->remove($rh); #$read_set->remove($serverSocket);
517 close($rh); #close($serverSocket);
518 print $client "Perl terminated wget and is about to exit\n";
519 last; # out of inner for loop
520 }
521 else { # the process may just be starting up, wait
522 sleep(1);
523 }
524 }
525 last; # out of foreach loop
526 }
527 }
528 }
529 }
530
531 my $command_status = $?;
532 if ($command_status != 0) {
533 $error_text .= "Exit error: $command_status";
534 }
535
536 if ($changed_dir) {
537 chdir $current_dir;
538 }
539
540 my $final_follow = pop(@follow_list); # might be undefined, but that's OK
541
542 return ($full_text,$error_text,$final_follow);
543}
544
545
546# TODO: Check if the URL is valid?? Not sure what should be in this function yet!!
547sub checkURL
548{
549 my ($self) = @_;
550 if ($self->{'url'} eq "")
551 {
552 &error("checkURL","no URL is specified!! Please specifies the URL for downloading.");
553 }
554}
555
556sub error
557{
558 my ($strFunctionName,$strError) = @_;
559 {
560 print "Error occoured in WgetDownload.pm\n".
561 "In Function:".$strFunctionName."\n".
562 "Error Message:".$strError."\n";
563 exit(-1);
564 }
565}
566
5671;
568
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