Program Structure
Data Types and Variables
Statements
Special Variables
Operators
Regular Expressions
Subroutines
References and Complex Data Structures
Filehandles
Signals
Unicode
Formats
Pod
This chapter is a quick and merciless guide to the Perl language itself. If you're trying to learn Perl from scratch and would prefer to be taught rather than to have things thrown at you, then you might be better off with Learning Perl, 3rd Edition by Randal L. Schwartz and Tom Phoenix. However, if you already know some other programming languages and just want to learn the particulars of Perl, this chapter is for you. Sit tight, and forgive us for being terse—we have a lot of ground to cover.
If you want a more complete discussion of the Perl language and its idiosyncrasies (and we mean complete), see Programming Perl, 3rd Edition by Larry Wall, Tom Christiansen, and Jon Orwant.
Perl is a particularly forgiving language, as far as program layout goes. There are no rules about indentation, newlines, etc. Most lines end with semicolons, but not everything has to. Most things don't have to be declared, except for a couple of things that do. Here are the bare essentials:
You may force yourself to declare your variables by including the use strict pragma in your programs (see Chapter 8, "Standard Modules" for more information on pragmas and strict in particular). This causes an error if you do not explicitly declare your variables.
Lines starting with = are interpreted as the start of a section of embedded documentation (pod), and all subsequent lines until the next =cut are ignored by the compiler. See Section 4.12, "Formats" later in this chapter for more information on pod format.
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