ЭЛЕКТРОННАЯ БИБЛИОТЕКА КОАПП |
Сборники Художественной, Технической, Справочной, Английской, Нормативной, Исторической, и др. литературы. |
19.9. Debugging the Raw HTTP ExchangeProblemYour CGI script is misbehaving strangely with your browser, and you suspect something in the HTTP header is missing. You want to find out exactly what your browser is sending to the server in the HTTP header. SolutionCreate your own fake web server, and point your browser at it, as shown in Example 19.6. Example 19.6: dummyhttpd#!/usr/bin/perl -w # dummyhttpd - start an HTTP daemon and print what the client sends use strict; use HTTP::Daemon; # need LWP-5.32 or better my $server = HTTP::Daemon->new(Timeout => 60, LocalPort => 8989); print "Please contact me at: <URL:", $server->url, ">\n"; while (my $client = $server->accept) { CONNECTION: while (my $answer = $client->get_request) { print $answer->as_string; $client->autoflush; RESPONSE: while (<STDIN>) { last RESPONSE if $_ eq ".\n"; last CONNECTION if $_ eq "..\n"; print $client $_; } print "\nEOF\n"; } print "CLOSE: ", $client->reason, "\n"; $client->close; undef $client; } DiscussionIt's hard to keep track of which versions of all the different browsers still have which bugs. The fake server program can save you days of head scratching, because sometimes a misbehaving browser doesn't send the server the right thing. Historically, we have seen aberrant browsers lose their cookies, mis-escape a URL, send the wrong status line, and do other even less obvious things. To use the fake server, it's best to run it on the same machine as the real server. That way your browser will still send it any cookies destined for that domain. Then instead of pointing your browser at: http://somewhere.com/cgi-bin/whatever use the alternate port given in the http://somewhere.com:8989/cgi-bin/whatever If you convince yourself that the client is behaving properly but wonder about the server, it's easiest to use the telnet program to manually talk to the remote server. % telnet www.perl.com 80 If you have LWP installed on your system, you can use the GET alias for the lwp-request program. This will follow any redirection chains, which can shed light on your problem. For example: % GET -esuSU http://mox.perl.com/perl/bogotic See AlsoThe documentation for the standard CGI module; Recipe 19.10 |