threads::shared::queue and semaphore become Thread::Semaphore

[p5sagit/p5-mst-13.2.git] / pod / perlfaq9.pod

diff --git a/pod/perlfaq9.pod b/pod/perlfaq9.pod
index f7b81d5..e643c33 100644 (file)
--- a/pod/perlfaq9.pod
+++ b/pod/perlfaq9.pod
@@ -1,6 +1,6 @@
 =head1 NAME
 
-perlfaq9 - Networking ($Revision: 1.3 $, $Date: 2001/10/16 13:27:22 $)
+perlfaq9 - Networking ($Revision: 1.9 $, $Date: 2002/04/07 18:46:13 $)
 
 =head1 DESCRIPTION
 
@@ -16,9 +16,9 @@ a program ("CGI script") and a web server (HTTPD). It is not specific
 to Perl, and has its own FAQs and tutorials, and usenet group, 
 comp.infosystems.www.authoring.cgi 
 
-The original CGI specification is at: http://hoohoo.ncsa.uiuc.edu/cgi/ 
+The original CGI specification is at: http://hoohoo.ncsa.uiuc.edu/cgi/
 
-Current best-practice RFC draft at: http://CGI-Spec.Golux.Com/ 
+Current best-practice RFC draft at: http://CGI-Spec.Golux.Com/
 
 Other relevant documentation listed in: http://www.perl.org/CGI_MetaFAQ.html
 
@@ -48,7 +48,12 @@ systems. CGI.pm selects an appropriate newline representation
 
 =head2 My CGI script runs from the command line but not the browser.  (500 Server Error)
 
-If you can demonstrate that you've read the FAQs and that 
+Several things could be wrong.  You can go through the "Troubleshooting
+Perl CGI scripts" guide at
+
+       http://www.perl.org/troubleshooting_CGI.html
+
+If, after that, you can demonstrate that you've read the FAQs and that 
 your problem isn't something simple that can be easily answered, you'll
 probably receive a courteous and useful reply to your question if you
 post it on comp.infosystems.www.authoring.cgi (if it's something to do
@@ -115,7 +120,7 @@ Here's one "simple-minded" approach, that works for most files:
 
 If you want a more complete solution, see the 3-stage striphtml
 program in
-http://www.perl.com/CPAN/authors/Tom_Christiansen/scripts/striphtml.gz
+http://www.cpan.org/authors/Tom_Christiansen/scripts/striphtml.gz
 .
 
 Here are some tricky cases that you should think about when picking
@@ -143,22 +148,28 @@ on text like this:
 
 =head2 How do I extract URLs?
 
-A quick but imperfect approach is
+You can easily extract all sorts of URLs from HTML with
+C<HTML::SimpleLinkExtor> which handles anchors, images, objects,
+frames, and many other tags that can contain a URL.  If you need 
+anything more complex, you can create your own subclass of 
+C<HTML::LinkExtor> or C<HTML::Parser>.  You might even use 
+C<HTML::SimpleLinkExtor> as an example for something specifically
+suited to your needs.
+
+Less complete solutions involving regular expressions can save 
+you a lot of processing time if you know that the input is simple.  One
+solution from Tom Christiansen runs 100 times faster than most
+module based approaches but only extracts URLs from anchors where the first
+attribute is HREF and there are no other attributes. 
+
+        #!/usr/bin/perl -n00
+        # qxurl - tchrist@perl.com
+        print "$2\n" while m{
+            < \s*
+              A \s+ HREF \s* = \s* (["']) (.*?) \1
+            \s* >
+        }gsix;
 
-    #!/usr/bin/perl -n00
-    # qxurl - tchrist@perl.com
-    print "$2\n" while m{
-       < \s*
-         A \s+ HREF \s* = \s* (["']) (.*?) \1
-       \s* >
-    }gsix;
-
-This version does not adjust relative URLs, understand alternate
-bases, deal with HTML comments, deal with HREF and NAME attributes
-in the same tag, understand extra qualifiers like TARGET, or accept
-URLs themselves as arguments.  It also runs about 100x faster than a
-more "complete" solution using the LWP suite of modules, such as the
-http://www.perl.com/CPAN/authors/Tom_Christiansen/scripts/xurl.gz program.
 
 =head2 How do I download a file from the user's machine?  How do I open a file on another machine?
 
@@ -240,7 +251,7 @@ function to handle encoding.
 The best source of detailed information on URI encoding is RFC 2396.
 Basically, the following substitutions do it:
 
-    s/([^\w()'*~!.-])/sprintf '%%%02x', $1/eg;   # encode
+    s/([^\w()'*~!.-])/sprintf '%%%02x', ord $1/eg;   # encode
 
     s/%([A-Fa-f\d]{2})/chr hex $1/eg;            # decode
 
@@ -266,7 +277,7 @@ with a complete URL. This redirection is handled by the web browser.
 
       use CGI qw/:standard/;
 
-      my $url = 'http://www.perl.com/CPAN/';
+      my $url = 'http://www.cpan.org/';
       print redirect($url);
 
 
@@ -371,7 +382,7 @@ mail addresses with a simple regex, such as
 C</^[\w.-]+\@(?:[\w-]+\.)+\w+$/>.  It's a very bad idea.  However,
 this also throws out many valid ones, and says nothing about
 potential deliverability, so it is not suggested.  Instead, see
-http://www.perl.com/CPAN/authors/Tom_Christiansen/scripts/ckaddr.gz,
+http://www.cpan.org/authors/Tom_Christiansen/scripts/ckaddr.gz ,
 which actually checks against the full RFC spec (except for nested
 comments), looks for addresses you may not wish to accept mail to
 (say, Bill Clinton or your postmaster), and then makes sure that the
@@ -601,7 +612,7 @@ an RPC stub generator and includes an RPC::ONC module.
 
 =head1 AUTHOR AND COPYRIGHT
 
-Copyright (c) 1997-1999 Tom Christiansen and Nathan Torkington.
+Copyright (c) 1997-2002 Tom Christiansen and Nathan Torkington.
 All rights reserved.
 
 This documentation is free; you can redistribute it and/or modify it