web development in perl

April 12, 2023 Naveen Gupta 1

Web Development in Perl

WEB DEVELOPMENT IN Perl

Naveen Gupta [email protected]



• AGENDA

– Introduction to Web Development & Perl– Perl Powered Sites/Application– Basic Web Programming in Perl– CGI Programming in Perl– Creating HTML Forms– mod_perl– Templating Systems in Perl– Web 2.0 Applications in Perl– Perl vs PHP - A Tale of 2 Languages



• Introduction to Web Development

What is Web Dev? – Development of websites, internet applications, e-

commerce sites, social networks etc.

– Includes Web Designing, Content Development, client/server side coding, Web Server configuration

– Flexible Model, easy to adopt to, Barriers to entry very low

– Contributing Factors - Propagation of Open Source Technologies, WYSIWYG Tools, Internet Awareness

– Killer Apps – Google Docs, Flickr, WordPress, PhpBB, WikiMedia, YouTube and millions others



• Dominant Technologies

– C, C++, Pascal, Shell Script– ASP– JAVA, J2EE and related Frameworks– Perl with or without CGI– PHP– .NET – C#, VB.NET– Python– Ruby on Rails– ColdFusion



• Introduction to Perl

– Created by Larry Wall in 1987– Interpreted, Scripting Language– C - like syntax– Best of C, awk and sed– Best language for Text Manipulation/ Data Processing– Swiss Army knife for SysAdmins, Programmers– Supports modules, OO, DB interaction, pointers, regular

expressions, multithreading, sockets, MVC frameworks– Highly Portable, well documented



• Perl and the WEB

– De facto language for CGI Programs– Made popular by Matt’s Script Archive– Easy to build and maintain– Wide acceptance of LAMP framework – Linux, Apache, MySQL,

PHP/Perl/Python/Ruby– Great DB support via DBI set of Modules– Strength of Perl – CPAN, Comprehensive Perl Archive

Network– Hands down winner with the advent of mod_perl, FastCGI,

Catalyst, Moose etc.



• How to get Perl?

- For *NIX Platforms – Included with almost every Linux, BSD, Solaris, OS X installation. Source can be can be downloaded from http://www.perl.org and compiled using “gcc”. RPMs are also available.

- For Windows Platforms – Installation Binary distributed by http://www.activestate.com as ActivePerl. Yet, complete LAMP installations distributed by http://www.apachefriends.org, http://www.apache.org, http://www.indigostar.com etc. are most popular. Complete listing can be found at http://www.perl.org/ports



Perl Powered Sites/Applications



My First Web Program in Perl

#!/usr/bin/perl

print “Content-type:/text/html\n\n”;

print “Hello World!<br>”;



Adding a Bit of `Perl`

#!/usr/bin/perl


my $time=localtime(time);

print “Today is $time <br>”;

foreach my $key (sort keys %ENV){print qq{$key = $ENV{$key} <br>};

}



Jazz it up with a little HTML

#!/usr/bin/perl


print “<h1>Welcome to my First Perl Web page</h1>”;print “Perl is a great language!<br>”;print “It can create killer websites too!<br>”;print “Wanna see how?”;



Here Document

#!/usr/bin/perl


print<<HTML;

<h1>Welcome to my First Perl Web page</h1>Perl is a great language!<br>It can create killer websites too!<br>Wanna see how?

HTML



Going Dynamic with CGI#!/usr/bin/perl

use CGI;use strict;

my $cgi=new CGI;

print $cgi->header();print $cgi->start_html(-title=>’First CGI.pm program’, -meta=>{‘keywords’=>’perl cgi’, ‘copyright’=>’WebOSS ‘07’}, -style=>{‘src’=>’style.css’}, -BGCOLOR=>’blue’);

contd….



…contd

Going Dynamic with CGI

print $cgi->h1(“Welcome to a CGI APP!”);print “Your IP Address is : ”.$ENV{‘REMOTE_ADDR’}.“<br>”;print “You have been directed here from:

$ENV{‘HTTP_REFERER’}” ;print $cgi->a({-href=>’http://search.cpan.org’, -target=>’_blank’}, “Go to CPAN!”);print $cgi->end_html;



• The Power of mod_perl“…mod_perl is more than CGI scripting on steroids. It is a whole new way to create dynamic content by utilizing the full power of the Apache web server to create stateful sessions, customized user authentication systems, smart proxies and much more. Yet, magically, your old CGI scripts will continue to work and work very fast indeed. With mod_perl you give up nothing and gain so much! …” – Lincoln Stein, Author – CGI.pm

- Perl Interpreter embedded in Apache

- Overcomes one-process-per-request limitation of CGI, 100x faster!

- Write Apache modules in Perl instead of C

- Hundreds of Modules available in CPAN

- Numerous Application Frameworks, Templating Systems

- Configure Apache’s httpd.conf via Perl



• Perl Templating Systems

– HTML::Mason

– Template Toolkit

– HTML::Template

– SSI using mod_include or Apache::SSI module

Why use Templating System?

• Consistency of Appearance

• Reusability

• Abstraction between logic and design

• Division of Labour



• Web 2.0 Apps in Perl CGI::Ajax

• Object Oriented module by Brian C. Thomas

• Eliminates the need to write JS for AJAX Calls

• Generates JS Functions from output by Perl subroutines

• Can be implemented in large projects

HTML::TagCloud

• Generates Tag Clouds, with different font sizes

• CSS Based

• Add method takes 3 arguments – a) Tag Name

b) URL to link to

c) Weight



WEB DEVELOPMENT IN Perl

Perl vs PHP



Perl PHPPURPOSE/

UTILITYMulti-purpose, primarily for text

pocessing, equally suited for sysadmin and web apps

Made primarily for WEB. Can do CLI and other tasks.

LEARNING CURVE

Easier than C, JAVA, .NET Easier than Perl

API/ LIBRARY SUPPORT

48606 active modules on CPAN and many others elsewhere

PEAR and PECL, both from http://www.php.net

DOCUMENTATION

Perldoc, http://perldoc.perl.org , CPAN

http://www.php.net

APACHE INTEGRATION

mod_perl, Fast CGI mod_php



Perl PHP

HTML EMBED Only with Modules like Mason, HTML::Template,

Template::Toolkit etc.

Yes, the main reason for its popularity

CMS / APPLICATIONS

AWStats, Slash Code, BugZilla WordPress, phpBB, Drupal, Coppermine,

phpMyAdmin



THANK YOU!

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