MooseX::Role::Cmd(3) User Contributed Perl Documentation MooseX::Role::Cmd(3)NAMEMooseX::Role::Cmd - Wrap system command binaries the Moose way
SYNOPSIS
Create your command wrapper:
package Cmd::Perl;
use Moose;
with 'MooseX::Role::Cmd';
has 'e' => (isa => 'Str', is => 'rw');
# other perl switches here...
1;
Use it somewhere else:
use Cmd::Perl;
my $perl = Cmd::Perl->new(e => q{'print join ", ", @ARGV'});
print $perl->run(qw/foo bar baz/);
# prints the STDOUT captured from running:
# perl -e 'print join ", ", @ARGV' foo bar baz
DESCRIPTIONMooseX::Role::Cmd is a Moose role intended to ease the task of building
command-line wrapper modules. It automatically maps Moose objects into
command strings which are passed to IPC::Cmd.
ATTRIBUTES
$cmd->bin_name
Sets the binary executable name for the command you want to run.
Defaults the to last part of the class name, lower-cased.
$cmd->stdout
Returns the STDOUT buffer captured after running the command.
$cmd->stderr
Returns the STDERR buffer captured after running the command.
METHODS
$bin_name = $cmd->build_bin_name
Builds the default string for the command name based on the class name.
@stdout = $cmd->run(@args);
Builds the command string and runs it based on the objects current
attribute settings. This will treat all the attributes defined in your
class as flags to be passed to the command.
NOTE: All quoting issues are left to be solved by the user.
cmd_args
Returns a list of the computed arguments that will be added to the
command
ADDITIONAL INFORMATION
Setting the Executable
By default the name of the binary executable is taken from the last
part of the class name (in lower case). The path is set during the run
method by scanning through your current PATH for the given executable
(see also the 'can_run' function from IPC::Cmd)
package MyApp::Commands::Scanner;
use Moose;
with 'MooseX::Role::Cmd';
$cmd = MyApp::Commands::Scanner->new();
$cmd->bin_name
# /path/to/scanner
If this default behaviour doesn't suit your application then you can
override the build_bin_name subroutine to explicitly set the executable
name
sub build_bin_name { 'scanner.exe' }
# /path/to/scanner.exe
Or you could explicitly set the path with
sub build_bin_name { '/only/use/this/path/scanner.exe' }
# /only/use/this/path/scanner.exe
How attributes are mapped to parameters
The attributes of the consuming package map directly to the parameters
passed to the executable. There are a few things to note about the
default behaviour governing the way these attributes are mapped.
Attribute Default Behaviour (@ARGV)
----------------------------------
single char prefix attr name with '-'
multiple char prefix attr name with '--'
boolean treat attr as flag (no value)
non-boolean treat attr as parameter (with value)
value=undef ignore attr
name=_name ignore attr
These points are illustrated in the following example:
package MyApp::Commands::Scanner;
use Moose;
with 'MooseX::Role::Cmd';
has 'i' => ( is => 'rw', isa => 'Str', default => 'input.txt' );
has 'out' => ( is => 'rw', isa => 'Str' );
has 'verbose' => ( is => 'rw', isa => 'Bool', default => 1 );
has 'level' => ( is => 'rw', isa => 'Int' );
has 'option' => ( is => 'rw', isa => 'Str' );
has '_internal' => ( is => 'ro', isa => Str, reader => internal, default => 'foo' );
# attribute names starting with '_' are not included
$scanner = MyApp::Commands::Scanner->new( output => '/tmp/scanner.log', level => 5 );
$scanner->run;
# /path/to/scanner -i input.txt --out /tmp/scanner.log --verbose --level 5
Changing names of parameters
It's possible that the parameters your system command expects do not
adhere to this naming scheme. In this case you can use the 'CmdOpt'
trait which allows you to specify exactly how you want the parameter to
appear on the command line.
has 'option' => ( isa => 'Bool' );
# --option
cmdopt_prefix
This lets you override the prefix used for the option (for example to
use the short form of multi-character options).
has 'option' => ( traits => [ 'CmdOpt' ],
isa => 'Bool',
cmdopt_prefix => '-'
);
# -option
cmdopt_name
This lets you completely override the option name with whatever string
you want
has 'option' => ( traits => [ 'CmdOpt' ],
isa => 'Bool',
cmdopt_name => '+foo'
);
# +foo
cmdopt_env
This will set an environment variable with the attribute name/value
rather than pass it along as a command line param
has 'home_dir' => ( traits => [ 'CmdOpt' ],
isa => 'Str',
cmdopt_env => 'APP_HOME'
default => '/my/app/home'
);
# ENV{APP_HOME} = /my/app/home
See MooseX::Role::Cmd::Meta::Attribute::Trait
PRIVATE METHODS
_attr_to_cmd_options
Returns an array (or array reference) of command options that
correspond to the given attribute name.
AUTHOR
Eden Cardim <edencardim@gmail.com>
LICENSE
This library is free software, you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.1 2010-02-15 MooseX::Role::Cmd(3)
