perl

(the language for getting your job done)

Internet Programming

Diana Hingst

Dynamic programming language Intended to be practical (easy to use &

efficient) Widely adopted for its text processing One of “The Three P’s” (Perl, PHP,

Python) for writing web applications

File system manipulation Database administration Client-server programming Secure programming Object-oriented programming GUI development

Created by Larry Wall in 1987

Designed as a glue for Unix OS

Originally named “PEARL”

Figure 1: Larry Wall

First Edition published in 1991 as a reference guide to Perl.

Previously, documentation was a single (very long) man page.

Perl 4 released.

Figure 2: Programming Perl Cover

http://www.cpan.org/

Answer: Both

1. Compiles into an intermediate format Optimizes & gives instant feedback

2. Interprets the intermediate format to execute

#Comment $number = “4”; $string = “3 apples”; @array = (“couch”, “movie”, “drink”); %hash = (joe => ‘red’, sam => ‘blue’);

$a ** $b #a^b $a . $b #String Concatenation $a x $b #Repeat a b times

$camels = ‘123’; print $camels + 1; # Prints 124

$a = “8”; print $a + “1”; # Prints 9 print $a . “1”; # Prints 81

Open a text editor Save with file extension .pl (or .cgi)

We’ve located the PERL interpreter and told it we’re going to be working with a web browser or in a web environment

Upload it to your web server Run the program in one of three ways

Link to it <a href=myscript.cgi>Click Here</a>

Write it into your HTML file <p><!--#include virtual=“myscript.cgi”-->

Action item of a form <form action=myscript.cgi>

Unix command line perl myscript.cgi

Perl Code

HTML Code

Data Tracing MechanismAutomatically determines which data was

derived from insecure sources Specially Protected Compartments

Able to safely execute Perl code that may be dangerous/insecure

Rotate Banners Generate Text & HTML on the fly Set Cookies Provide Shopping Carts

Amazon.com LiveJournal.com Ticketmaster.com IMDb.com

Writing poems that can actually be compiled as legal Perl code.

if ((light eq dark) && (dark eq light)&& ($blaze_of_night{moon} ==

black_hole)&& ($ravens_wing{bright} ==

$tin{bright})){my $love = $you = $sin{darkness} + 1;};

Programming Perl 2nd Edition http://websitehelpers.com/perl/ http://www.tizag.com/perlT/index.php http://www.linuxjournal.com/article/3394 http://en.wikipedia.org/wiki/Larry_Wall http://en.wikipedia.org/wiki/Perl http://www.foo.be/docs/tpj/issues/

vol5_1/tpj0501-0012.html