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+** Getopt::Long
+
+[[http://search.cpan.org/perldoc?Getopt::Long][Getopt::long]] is a
+useful module to parse command line arguements.
+
+A basic usage is something like this:
+
+#+BEGIN_SRC perl
+    #!/usr/bin/perl -w
+    use strict;
+    use YAML::Syck;
+    use Getopt::Long;
+
+    GetOptions('config=s' => \my $cfg_file,);
+
+    my $config = LoadFile $cfg_file
+#+END_SRC
+
+In *GetOptions*, we require a value for config with *config=s*. If we
+wante an integer, we replace 's' with 'i', and for a floating point,
+with 'f'.
+
+Call your script :
+
+#+BEGIN_EXAMPLE
+    % script.pl --config=file.yml #this one works
+    % script.pl --config file.yml #this one too!
+    % script.pl -c file.yml       #and this one too
+#+END_EXAMPLE
+
+The three syntaxes are understood.
+
+A good practices is to combine this module with
+[[http://search.cpan.org/perldoc?Pod::Usage][Pod::Usage]]. Let's do some
+modifications on the example:
+
+#+BEGIN_SRC perl
+    #!/usr/bin/perl -w
+    use strict;
+    use YAML::Syck;
+    use Getopt::Long;
+    use Pod::Usage;
+
+    GetOptions('config=s' => \my $cfg_file,) or pod2usage(2);
+    pod2usage(2) unless @ARGV > 0;
+
+    my $config = LoadFile $cfg_file
+
+    __END__
+    =head1 NAME
+
+    uberscript
+
+    =head1 SYNOPSIS
+
+    uberscript [options]
+
+    Options:
+
+        --config  config file
+
+    =head1 Options
+
+    =over 4
+
+    =item B<config>
+
+    Path to the config file
+#+END_SRC
+
+then
+
+#+BEGIN_EXAMPLE
+    % perl uberscript
+
+    Usage:
+        uberscript [options]
+
+        Options:
+            --config  config file
+#+END_EXAMPLE
+
+From now if we call our script without argument, the POD will be printed
+on STDIN.
+
+** MooseX::Getopt
+
+[[http://search.cpan.org/perldoc?MooseX::Getopt][MooseX::Getopt]] is a
+Role that add a =new_with_options= to your object. We create a basic
+Object :
+
+#+BEGIN_SRC perl
+    package OurShinyObject;
+
+    use Moose;
+    with qw/MooseX::Getopt/;
+
+    has 'config' => (isa => 'Str', is => 'ro', required => 1);
+    has 'context' => (
+        isa     => 'HashRef',
+        is      => 'rw',
+        lazy    => 1,
+        traits  => ['NoGetopt'],
+        default => sub { LoadFile shift->config }
+    );
+
+    ...
+#+END_SRC
+
+create a script to call this object
+
+#+BEGIN_SRC perl
+    #!/usr/bin/perl -w
+    use strict;
+    use OurShinyObject;
+
+    my $obj = OurShinyObject->new_from_options();
+#+END_SRC
+
+#+BEGIN_SRC sh
+    % script.pl --config file.yml
+#+END_SRC
+
+The role will set our attribute *context* using the value from the
+argument set on the command line.
+
+The =traits => ['NoGetopt']= indicate that this attributes will be not
+be read from the command line. An alternate way to do this is to prefix
+the attributes with **\_**.
+
+** conclusion (?)
+
+When you write a script, even if you're sure you will never need to have
+more than one argument, or that you never will have to update the code,
+/please/ consider to use of *Getopt::Long* instead of a =shift @ARGV=,
+because we all know that you will at a certain point update this script
+and you will more than one argument :).