diff options
Diffstat (limited to 'contrib/perl5/pod/perlfaq9.pod')
| -rw-r--r-- | contrib/perl5/pod/perlfaq9.pod | 107 |
1 files changed, 54 insertions, 53 deletions
diff --git a/contrib/perl5/pod/perlfaq9.pod b/contrib/perl5/pod/perlfaq9.pod index 6536064..16a803c 100644 --- a/contrib/perl5/pod/perlfaq9.pod +++ b/contrib/perl5/pod/perlfaq9.pod @@ -1,6 +1,6 @@ =head1 NAME -perlfaq9 - Networking ($Revision: 1.24 $, $Date: 1999/01/08 05:39:48 $) +perlfaq9 - Networking ($Revision: 1.26 $, $Date: 1999/05/23 16:08:30 $) =head1 DESCRIPTION @@ -76,11 +76,13 @@ stamp prepended. =head2 How do I remove HTML from a string? -The most correct way (albeit not the fastest) is to use HTML::Parse -from CPAN (part of the HTML-Tree package on CPAN). +The most correct way (albeit not the fastest) is to use HTML::Parser +from CPAN. Another mostly correct +way is to use HTML::FormatText which not only removes HTML but also +attempts to do a little simple formatting of the resulting plain text. Many folks attempt a simple-minded regular expression approach, like -C<s/E<lt>.*?E<gt>//g>, but that fails in many cases because the tags +C<< s/<.*?>//g >>, but that fails in many cases because the tags may continue over line breaks, they may contain quoted angle-brackets, or HTML comment may be present. Plus folks forget to convert entities, like C<<> for example. @@ -100,7 +102,7 @@ a solution: <IMG SRC = "foo.gif" ALT = "A > B"> - <IMG SRC = "foo.gif" + <IMG SRC = "foo.gif" ALT = "A > B"> <!-- <A comment> --> @@ -131,12 +133,11 @@ A quick but imperfect approach is }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, 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. +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? @@ -147,7 +148,7 @@ the same as the startform() method. =head2 How do I make a pop-up menu in HTML? -Use the B<E<lt>SELECTE<gt>> and B<E<lt>OPTIONE<gt>> tags. The CGI.pm +Use the B<< <SELECT> >> and B<< <OPTION> >> tags. The CGI.pm module (available from CPAN) supports this widget, as well as many others, including some that it cleverly synthesizes on its own. @@ -159,8 +160,9 @@ on your system, is this: $html_code = `lynx -source $url`; $text_data = `lynx -dump $url`; -The libwww-perl (LWP) modules from CPAN provide a more powerful way to -do this. They work through proxies, and don't require lynx: +The libwww-perl (LWP) modules from CPAN provide a more powerful way +to do this. They don't require lynx, but like lynx, can still work +through proxies: # simplest version use LWP::Simple; @@ -168,12 +170,12 @@ do this. They work through proxies, and don't require lynx: # or print HTML from a URL use LWP::Simple; - getprint "http://www.sn.no/libwww-perl/"; + getprint "http://www.linpro.no/lwp/"; # or print ASCII from HTML from a URL # also need HTML-Tree package from CPAN use LWP::Simple; - use HTML::Parse; + use HTML::Parser; use HTML::FormatText; my ($html, $ascii); $html = get("http://www.perl.com/"); @@ -213,11 +215,11 @@ Here's an example of decoding: $string =~ s/%([a-fA-F0-9]{2})/chr(hex($1))/ge; Encoding is a bit harder, because you can't just blindly change -all the non-alphanumeric characters (C<\W>) into their hex escapes. +all the non-alphanumunder character (C<\W>) into their hex escapes. It's important that characters with special meaning like C</> and C<?> I<not> be translated. Probably the easiest way to get this right is to avoid reinventing the wheel and just use the URI::Escape module, -which is part of the libwww-perl package (LWP) available from CPAN. +available from CPAN. =head2 How do I redirect to another page? @@ -236,9 +238,21 @@ because of "optimizations" that servers do. print "Location: $url\n\n"; exit; -To be correct to the spec, each of those C<"\n"> -should really each be C<"\015\012">, but unless you're -stuck on MacOS, you probably won't notice. +To target a particular frame in a frameset, include the "Window-target:" +in the header. + + print <<EOF; + Location: http://www.domain.com/newpage + Window-target: <FrameName> + + EOF + +To be correct to the spec, each of those virtual newlines should really be +physical C<"\015\012"> sequences by the time you hit the client browser. +Except for NPH scripts, though, that local newline should get translated +by your server into standard form, so you shouldn't have a problem +here, even if you are stuck on MacOS. Everybody else probably won't +even notice. =head2 How do I put a password on my web pages? @@ -329,7 +343,7 @@ RFC-822 (the mail header standard) compliant, and addresses that aren't deliverable which are compliant. Many are tempted to try to eliminate many frequently-invalid -mail addresses with a simple regexp, such as +mail addresses with a simple regex, such as C</^[\w.-]+\@([\w.-]\.)+\w+$/>. It's a very bad idea. However, this also throws out many valid ones, and says nothing about potential deliverability, so is not suggested. Instead, see @@ -382,12 +396,12 @@ format after minor transliterations: =head2 How do I return the user's mail address? -On systems that support getpwuid, the $E<lt> variable and the +On systems that support getpwuid, the $< variable and the Sys::Hostname module (which is part of the standard perl distribution), you can probably try using something like this: use Sys::Hostname; - $address = sprintf('%s@%s', getpwuid($<), hostname); + $address = sprintf('%s@%s', scalar getpwuid($<), hostname); Company policies on mail address can mean that this generates addresses that the company's mail system will not accept, so you should ask for @@ -423,7 +437,12 @@ the message into the queue. This last option means your message won't be immediately delivered, so leave it out if you want immediate delivery. -Or use the CPAN module Mail::Mailer: +Alternate, less convenient approaches include calling mail (sometimes +called mailx) directly or simply opening up port 25 have having an +intimate conversation between just you and the remote SMTP daemon, +probably sendmail. + +Or you might be able use the CPAN module Mail::Mailer: use Mail::Mailer; @@ -438,34 +457,17 @@ Or use the CPAN module Mail::Mailer: The Mail::Internet module uses Net::SMTP which is less Unix-centric than Mail::Mailer, but less reliable. Avoid raw SMTP commands. There -are many reasons to use a mail transport agent like sendmail. These +are many reasons to use a mail transport agent like sendmail. These include queueing, MX records, and security. =head2 How do I read mail? -Use the Mail::Folder module from CPAN (part of the MailFolder package) or -the Mail::Internet module from CPAN (also part of the MailTools package). - - # sending mail - use Mail::Internet; - use Mail::Header; - # say which mail host to use - $ENV{SMTPHOSTS} = 'mail.frii.com'; - # create headers - $header = new Mail::Header; - $header->add('From', 'gnat@frii.com'); - $header->add('Subject', 'Testing'); - $header->add('To', 'gnat@frii.com'); - # create body - $body = 'This is a test, ignore'; - # create mail object - $mail = new Mail::Internet(undef, Header => $header, Body => \[$body]); - # send it - $mail->smtpsend or die; - -Often a module is overkill, though. Here's a mail sorter. - - #!/usr/bin/perl +While you could use the Mail::Folder module from CPAN (part of the +MailFolder package) or the Mail::Internet module from CPAN (also part +of the MailTools package), often a module is overkill, though. Here's a +mail sorter. + + #!/usr/bin/perl # bysub1 - simple sort by subject my(@msgs, @sub); my $msgno = -1; @@ -476,12 +478,12 @@ Often a module is overkill, though. Here's a mail sorter. $sub[++$msgno] = lc($1) || ''; } $msgs[$msgno] .= $_; - } + } for my $i (sort { $sub[$a] cmp $sub[$b] || $a <=> $b } (0 .. $#msgs)) { print $msgs[$i]; } -Or more succinctly, +Or more succinctly, #!/usr/bin/perl -n00 # bysub2 - awkish sort-by-subject @@ -541,7 +543,7 @@ All rights reserved. When included as part of the Standard Version of Perl, or as part of its complete documentation whether printed or otherwise, this work -may be distributed only under the terms of Perl's Artistic Licence. +may be distributed only under the terms of Perl's Artistic License. Any distribution of this file or derivatives thereof I<outside> of that package require that special arrangements be made with copyright holder. @@ -551,4 +553,3 @@ are hereby placed into the public domain. You are permitted and encouraged to use this code in your own programs for fun or for profit as you see fit. A simple comment in the code giving credit would be courteous but is not required. - |
