Perl

From Wikipedia:

Perl is a family of high-level, general-purpose, interpreted, dynamic programming languages. The languages in this family include Perl 5 and Raku (formerly Perl 6).

The Perl languages borrow features from other programming languages including C, shell script (sh), AWK, and sed. They provide powerful text processing facilities without the arbitrary data-length limits of many contemporary Unix commandline tools, facilitating easy manipulation of text files. Perl 5 gained widespread popularity in the late 1990s as a CGI scripting language, in part due to its then unsurpassed regular expression and string parsing abilities.

Installation

Install the perl package.

Commands

The Perl language interpreter:

$ perl

Perl bug reporting:

$ perlbug

Lookup the Perl documentation in POD format:

$ perldoc

Send the Perl authors and maintainers a thank you message:

$ perlthanks

Package management

The Comprehensive Perl Archive Network (CPAN) is a repository of over 250,000 software modules and accompanying documentation written in the Perl programming language by over 12,000 contributors.

CPAN is also the name of a Perl module, CPAN.pm, which is used to download and install Perl software from the CPAN archive.

pacman and AUR

A number of popular CPAN modules are available as packages in the Arch repositories. There are further modules available in the AUR.

CPAN.pm

The CPAN.pm module is included with Perl. It can be used interactively from the shell or in Perl scripts.

Configuring cpan

Before first use, the module needs to be configured. This is done interactively from the shell with (some output omitted):

$ cpan

CPAN.pm requires configuration, but most of it can be done automatically.
If you answer 'no' below, you will enter an interactive dialog for each
configuration option instead.

Would you like to configure as much as possible automatically? [yes]

Automated configuration will suit most users. Answering yes, the configuration will continue with:

To install modules, you need to configure a local Perl library directory or
escalate your privileges. CPAN can help you by bootstrapping the local::lib
module or by configuring itself to use 'sudo' (if available). You may also
resolve this problem manually if you need to customize your setup.

What approach do you want?  (Choose 'local::lib', 'sudo' or 'manual')
 [local::lib]

If you want cpan to install modules in your home directory choose local::lib. To install them system-wide choose sudo. Choosing sudo the configuration ends:

Autoconfiguration complete.

commit: wrote '/home/username/.cpan/CPAN/MyConfig.pm'

Choosing the local::lib option will result in addition modules being installed.

Choosing not to use automated configuration allows the user to set cpan options interactively in the shell. The table below shows some option names with a brief description and default value. More detailed information is displayed for each option during configuration.

Name	Description	Default
cpan_home	CPAN build and cache directory	$HOME/.cpan
keep_source_where	Download target directory	$HOME/.cpan/sources
build_dir	Build process directory	$HOME/.cpan/build
prefs_dir	Customizable modules options directory	$HOME/.cpan/prefs
build_cache	Cache size for build directory	100MB
cleanup_after_install	Remove build directory after successful install	No
shell	Preferred shell	/bin/bash
halt_on_failure	Halt on failure	No
colorize_output	Turn on colored output	No
histfile	History file location	$HOME/.cpan/histfile
histsize	History file size	100 lines

The configuration file $HOME/.cpan/CPAN/MyConfig.pm can be edited with your text editor of choice.

Usage examples

To simply install a modules pass them as parameters to cpan (multiple module names are separated by spaces):

$ cpan Acme::MetaSyntactic

The following examples are all in the cpan interactive shell, started with:

$ cpan

Display information on a module:

cpan[1]> m Acme::MetaSyntactic

Reading '/home/username/.cpan/Metadata'
  Database was generated on Fri, 08 Dec 2017 02:17:03 GMT
Module id = Acme::MetaSyntactic
    CPAN_USERID  BOOK (Philippe Bruhat (BooK) <book@cpan.org>)
    CPAN_VERSION 1.014
    CPAN_FILE    B/BO/BOOK/Acme-MetaSyntactic-1.014.tar.gz
    INST_FILE    (not installed)

View module README:

cpan[2]> readme Acme::MetaSyntactic

Acme::MetaSyntactic - Themed metasyntactic variables

DESCRIPTION

When writing code examples, it's always easy at the beginning:

   my $foo = "bar";
   $foo .= "baz";   # barbaz
...

Install a module:

cpan[3]> install Acme::MetaSyntactic

Widget bindings

The following widget toolkit bindings are available:

gtk2-perl — GTK2 bindings

https://gtk2-perl.sourceforge.net/ || gtk2-perl

perl-gtk3 — GTK3 bindings

https://metacpan.org/release/Gtk3 || perl-gtk3

Perl/TK — Tk bindings

https://search.cpan.org/dist/Tk/ || perl-tk

wxPerl — wxWidgets bindings

http://www.wxperl.it/ || perl-wx^AUR

Prima — a perl multiplatform graphic toolkit

https://metacpan.org/release/Prima || perl-prima^AUR

To use these with Perl, you may need to install the associated widget kits.

Development in JetBrains IDE

If you are using a JetBrains IDE, for example IntelliJ Idea, install perl-bundle-camelcade^AUR. Then install Perl plugin. Then go to the Settings > Languages & Frameworks > Perl5. In the Perl 5 Interpreter field select Add System Perl. Now you can make a run/debug configuration for your project and start debugging.

Tips and tricks

Improved module management

cpanminus

cpanminus extends module management and aims to be zero configuration and integrates with local::db.

Install the cpanminus package.

The cpanminus documentation gives examples.

ucpan

ucpan is a nice, fully automatic updater for CPAN modules (especially installed in local-lib). To install use:

cpan App::ucpan

Bundle::CPAN

Installing the Bundle::CPAN distribution will add a lot of nice functionality to CPAN.pm.

$ cpan Bundle::CPAN

Re-run cpan configuration

$ cpan
cpan[1]> o conf init

Create new module

module-starter

Module::Starter helps you create your new module... Install:

cpanm Module::Starter

Usage:

module-starter --module=App::foobar  --author="My name here" --email=my@email.here --mb

This going to create your module tree...

Note: Option --mb create module which will use Module::Build. The next part assumes that you are using this module.

To add dependiences, put module_name => version_or_0 inside $builder -> requires in file Build.PL

To install required dependiences for your project, run inside App-foobar folder:

cpanm --installdeps .

To skip git folder, add under $builder

add_to_manifest_skip => [ '.git' ],

Adding scripts can by done like this:

mkdir bin
touch bin/foobar

To run this script:

perl -Ilib bin/foobar

You can change your project version here: lib/App/foobar.pm

To install your module run this command in module root folder:

cpanm .

See more on: cpan page, cookbook