Perl is a scripting language that was developed in the 1980's by Larry Wall to extend the functionality of sed and awk. It is an acronym for Practical Extraction and Reporting Language but has grown far bigger than its original purpose and today it is available on Unix, Linux, OS X, and Windows operating systems.

Although, it is a scripting language, it is not shell scripting; as such there is no Perl shell. This means that the code has to be executed via Perl scripts and not directly from the command line. The exception to this is the -e option to the perl command that can allow you to execute a perl statement. For example, we can use the following command line to print the ubiquitous Hello World:

$ perl -e ' print("Hello World\n");'

You will find that Perl is installed by default on most Linux and Unix systems as many programs will make use of Perl in their code. To check the version of Perl that you have installed on your system you can use the perl command, as follows:

$ perl...