Perl Cookbook

Conventions Used in This Book

Programming Conventions

We are firm believers in using Perl’s -w command-line option and its use strict pragma in every non-trivial program. We start nearly all our longer programs with:

#!/usr/bin/perl -w
use strict;

We give lots of examples, most of which are pieces of code that should go into a larger program. Some examples are complete programs, which you can recognize because they begin with a #! line.

Still other examples are things to be typed on a command line. We’ve used % to indicate the shell prompt:

% perl -e 'print "Hello, world.\n"'

                  Hello, world.

This style is representative of a standard Unix command line. Quoting and wildcard conventions on other systems vary. For example, most standard command-line interpreters under DOS and VMS require double quotes instead of single ones to group arguments with spaces or wildcards in them. Adjust accordingly.

Typesetting Conventions

The following typographic conventions are used in this book:

Italic

is used for filenames, command names, and URLs. It is also used to define new terms when they first appear in the text.

Bold

is used for command-line options.

Constant Width

is used for function and method names and their arguments; in examples to show the text that you enter literally; and in regular text to show any literal code.

Constant Bold Italic

is used in examples to show output produced.

Documentation Conventions

The most up-to-date and complete documentation about Perl is included with Perl itself. ...