Abstract Green

What is Perl and why is it so good?

Martin Houston, Deluxe Technology Ltd

Perl is a language that has been in wide use for over 1/4 of a century.Where did it come from?What has it been used for?Why it is still relivant in 2017?

Some History

Perl was begun in 1987 by brilliant programmer Larry Wall.

By the early 90s was available for wide variety of Unix systems over the Internet.

Way better than writing in shell, sed & awk!

In 1994 the new massivley more powerful Perl5 version released.

Turned out it was the perfect tool to work with the rapidly developing World Wide Web fast turnaround.

Perl & the Internet

Perl already established as the easiest way to write software FAST for Unix systems.

Early web servers mostly ran on such systems so initial explosive growth of the WWW on the back of Perl.

Some manufacturers like Sun Microsystems started using Perl to write much of their OS software.

When Linux came along Perl was already so well established it is a part of every Linux build.

Internet brings new challengers

There are more Perl like languages today:

Python

Ruby

PHP

All borrow features from Perl in particular the Regular Expressions.

Perl5 is still the dominant version of Perl!

New releases introduce improvments without breaking compatability.

Decades of stability means huge existing software base!

Perl designed for quick fixes

It was designed to solve the practical problems of keeping big computers running day-to-day.

Not really for the construction of huge sooftware engineering projects by thousand man teams.

Many very useful things can be done by one liners and programs that fit on a sheet of paper.

Try that with BASIC or Java!

But good for big projects too!

Although the newer languages like Python are a little more suited Perl has been used for some really big pieces of software such as:

Twiki

Bugzilla

Bioinformatics (gene sequencing)Many websites using one of the modern OO frameworks.

Or plain old CGI.

Perl interfaces to countless databases with ease of course!

Why Perl remains a good choice

No size limits if you have a 128GB memory machine perl will make use of it. Handling data in memory always fast!

The default variables of $_ and @_ make many common operations much less wordy

The object orentation model is lightweight and easy to understand. You are not forced into using it.

HUGE existing library if tested solutions called CPAN

Unit testing of code has been part of Perl development for decades

Why Perl is best choice for data conversion

Can work with huge amounts of data types uncluding binary thanks to pack/unkack operators

Lots of useful work like bulk editing of files to fix 1 mistake can be done as one liners.

Leveraging the CPAN library means even small programs can do very complex things like web page scraping or xml parsing.

No separate compilation. The source is all you need to keep around.

Why choose Deluxe Technology

Over 25 years experince in using Perl to solve huge variety of computer problems.

This gives faster turnaround than having to learn everything from scratch.

Which enables data conversion projects to be handled on a fixed price basis.

Think of it as computer plumbing!

Thank you for watching.