Tag: perl

Create command-line applications with both human and computer friendly output in Perl

https://perlancar.wordpress.com/2015/03/13/pericmd-039-creating-api-friendly-cli-applications-with-parseable-outputs/ ᔥ

Outputs in various tabular formats…

% ./list-files -v
+----------------+------+------+
| name           | size | type |
+----------------+------+------+
| hello          | 1131 | f    |
| list-files     | 988  | f    |
| list-files~    | 989  | f    |
| mycomp         | 902  | f    |
| mycomp2a       | 608  | f    |
| mycomp2b       | 686  | f    |
| mycomp2b+comp  | 1394 | f    |
| pause          | 4096 | d    |
| perl-App-hello | 4096 | d    |
+----------------+------+------+

…Or JSON format:

% ./list-files --json
[200,"OK",["hello","list-files","list-files~","mycomp","mycomp2a","mycomp2b","mycomp2b+comp","pause","perl-App-hello"],{}]

Moose: Perl module that extends the Perl 5 object system to make programming easier, more consistent, and less tedious

http://search.cpan.org/~ether/Moose-2.1402/lib/Moose.pm ᔥ

This module has me interested in writing some Perl code for the first time in years. I’m going to check this out.

Example from perldocs:

package Person;

use Moose;

has 'first_name' => (
    is  => 'rw',
    isa => 'Str',
);

has 'last_name' => (
    is  => 'rw',
    isa => 'Str',
);

no Moose;
__PACKAGE__->meta->make_immutable;

This is a complete and usable class definition!

package User;

use DateTime;
use Moose;

extends 'Person';

has 'password' => (
    is  => 'rw',
    isa => 'Str',
);

has 'last_login' => (
    is      => 'rw',
    isa     => 'DateTime',
    handles => { 'date_of_last_login' => 'date' },
);

sub login {
    my $self = shift;
    my $pw   = shift;

    return 0 if $pw ne $self->password;

    $self->last_login( DateTime->now() );

    return 1;
}

no Moose;
__PACKAGE__->meta->make_immutable;

When ready to instantiate your class in an application, use it in the “traditional” Perl manner:

use User;

my $user = User->new(
  first_name => 'Example',
  last_name  => 'User',
  password   => 'letmein',
);

$user->login('letmein');

say $user->date_of_last_login;

Mojolicious: Modern Perl web framework

mojolicious

I haven’t written any Perl in years, but this looks promising.

From the website:

  • An amazing real-time web framework, allowing you to easily grow single file Mojolicious::Lite prototypes into well structured web applications.
  • Powerful out of the box with RESTful routes, plugins, commands, Perl-ish templates, content negotiation, session management, form validation, testing framework, static file server, first class Unicode support and much more for you to discover.
  • Very clean, portable and Object Oriented pure-Perl API without any hidden magic and no requirements besides Perl 5.10.1 (although 5.18+ is recommended, and optional CPAN modules will be used to provide advanced functionality if they are installed).
  • Full stack HTTP and WebSocket client/server implementation with IPv6, TLS, SNI, IDNA, Comet (long polling), keep-alive, connection pooling, timeout, cookie, multipart, proxy and gzip compression support.
  • Built-in non-blocking I/O web server, supporting multiple event loops as well as optional preforking and hot deployment, perfect for embedding.
  • Automatic CGI and PSGI detection.
  • JSON and HTML/XML parser with CSS selector support.
  • Fresh code based upon years of experience developing Catalyst.