Book Image

Perl 6 Deep Dive

By : Andrew Shitov
Book Image

Perl 6 Deep Dive

By: Andrew Shitov

Overview of this book

Perl is a family of high-level, general-purpose, interpreted, dynamic programming languages consisting of Perl 5 and Perl 6. Perl 6 helps developers write concise and declarative code that is easy to maintain. This book is an end-to-end guide that will help non-Perl developers get to grips with the language and use it to solve real-world problems. Beginning with a brief introduction to Perl 6, the first module in the book will teach you how to write and execute basic programs. The second module delves into language constructs, where you will learn about the built-in data types, variables, operators, modules, subroutines, and so on available in Perl 6. Here the book also delves deeply into data manipulation (for example, strings and text files) and you will learn how to create safe and correct Perl 6 modules. You will learn to create software in Perl by following the Object Oriented Paradigm. The final module explains in detail the incredible concurrency support provided by Perl 6. Here you will also learn about regexes, functional programming, and reactive programming in Perl 6. By the end of the book, with the help of a number of examples that you can follow and immediately run, modify, and use in practice, you will be fully conversant with the benefits of Perl 6.
Table of Contents (15 chapters)

Standard input and output

In the previous chapters, we have created many programs that print to the console and read data from it. Let us refresh some knowledge from Chapter 2, Writing Code, and create a program that asks for the user's name and greets them:

my $name = prompt 'What is your name? ';
say "Hello, $name!";
note "Greeted $name at " ~ time;

Here, the prompt function prints the message and waits until the user enters a string. The string is saved in the $name variable, which is later interpolated in a string in double quotes. The note function prints the debugging message and logs the time of when the person was greeted.

In this program, Perl 6 uses two standard communication channels, the standard input stream (stdin for short) and the standard output stream (stdout). These are the default streams that receive the user's input...