QuickStart Languages

QuickStart Perl

by Alex Kashevarov

About the language

Name:	Perl
Year created:	1987
Created by:	Larry Wall and a cast of others
Paradigm:	Object-oriented(Perl is a very flexible language and can be adopted to a variety of uses, procedural C-like programs can also be created)
Platform:	Platform-independent, uses an interpretor to translate code for a specific machine.
Domain:	Web applications, Database, General applications (System scripts, etc.)
Advantages:	Platform independence (Code can be used on UNIX and Microsoft machines without any modification), security, excellent documentation, modularization (i.e. packages), flexibility (arbitrary data structures, security and other built-in checks by the compiler at runtime).
Disadvantages:	Uses an interpretor so it can be slower than true compiled languages like C/C++, but as computers are getting faster the perceptible difference between interpreted and compliled code is diminishing
Specification:	http://perldoc.perl.org/perl.html
Grammar:	http://search.cpan.org/dist/perl/pod/perlsyn.pod

Step-by-step instructions for learning to program in Perl:

Step 1. Download and install the latest source code release

Go to the Perl website (http://www.perl.com/download.csp), choose the release version according to the platform and OS that you are using.
The downloaded zipped file contains the documentation for Perl as well as the installation instructions specific for the given platform.

Step 2. Writing programs in Perl

There is no need to have some specific editor for Perl, a simple text editor like WordPad will suffice. The nuances to remeber are that the file must be saved with a .pl at the end and that the first line of your program must point to the perl executable (explained further in the next step).
For those who prefer to use something more sophisticated, there are many free and not so free IDEs available. A few free ones are:
- Open Perl IDE - for Windows 95/98/NT/2000
- PerlEdit - for Windows and Linux
If you have a large project to do, it is worth checking the long list of available perl modules, chances are someone has already done the work for you :D
- more about modules
Module installation guide can be found here.

Step 3. Write a "hello world" program (for Windows)

print "Hello, world!\n";

Step 4. Run the "hello world" program

Make sure the Perl executable is on your path (that .pl files are set to be opened by the perl executable).
Now type the following command at your command prompt:

perl hello.pl

Hello, world!

Step 5. Going beyond the basics

Step 6. Using Perl scripts with extra priviliges (System Administration)

Perl Security Tips - what precautions should be taken when a perl script works with valuable/confidential data
More about security - tainted data checks, path clean up.

		

Learning more

There is a vast amount of information available on the Internet. Some of the best sources are: