The Aura CLI package provides a system for creating and executing CLI Command objects. It includes facilities for parsing command-line options and handling standard input/output.

The logic for the Command goes in the action() method. In the example below, we perform some basic input/output.

<?php
namespace Vendor\Package;
use Aura\Cli\Command;

class Example extends Command
{
    public function action()
    {
        $this->stdio->outln('Hello World!');
        $this->stdio->out('Please enter some text: ');
        $input = $this->stdio->in();
        $this->stdio->errln('Input was ' . $input);
    }
}

When we invoke that Command, it will output "Hello World!", ask for some input, and then print that input to the error stream.

Use the $stdio object to work with standard input/output streams. Its methods are:

• outln() and out(): Print to stdout, with or without a line ending.

• errln() and err(): Print to stderr, with or without a line ending.

• inln() and in(): Read from stdin until the user hits enter; inln() leaves the trailing line ending in place, whereas in() strips it.

There are four method hooks on the CLI Command. Use the pre- and post-action methods to perform logic before and after the action; use pre- and post-exec methods to perform setup and teardown.

<?php
namespace Vendor\Package;
use Aura\Cli\Command;

class Example extends Command
{
    protected $input = 'foo bar baz';
    
    public function preExec()
    {
        // perform object setup here
    }
    
    public function preAction()
    {
        $this->stdio->outln('The input is currently ' . $this->input);
    }
    
    public function action()
    {
        $this->stdio->out('Please enter some text: ');
        $this->input = $this->stdio->in();
    }
    
    public function postAction()
    {
        $this->stdio->outln('The input was ' . $this->input);
    }
    
    public function postExec()
    {
        // perform object teardown here
    }
}

We may wish to pass information as part of the invocation. To read this information while in the Command, use $this->params.

<?php
namespace Vendor\Package;
use Aura\Cli\Command;

class Example extends Command
{
    public function action()
    {
        foreach ($this->params as $key => $val) {
            $this->stdio->outln("Param $key is '$val'.");
        }
    }
}

For example, if we issue ...

$ php command.php foo bar baz

... then the action() will output:

Param 0 is 'foo'.
Param 1 is 'bar'.
Param 2 is 'baz'.

In addition to argument params, we may wish to pass certain short switches or long options as part of the invocation. These are the -a and --option=value portions of the invocation.

To work with options, we first define them in the $options array of the Command. Then we can retrieve the option values through the $getopt object.

To define an option, do something like the following:

<?php
namespace Vendor\Package;
use Aura\Cli\Command;
use Aura\Cli\Option;

class Example extends Command
{
    protected $options = [
        'foo_bar' => [
            'long'    => 'foo-bar',
            'short'   => 'f',
            'param'   => Option::PARAM_REQUIRED,
            'multi'   => false,
            'default' => null,
        ],
    ];
    
    public function action()
    {
        $this->stdio->out("The value of -f/--foo-bar is ")
        $this->stdio->outln($this->getopt->foo_bar);
    }
}

When we invoke the above Command like this ...

$ php command.php --foo-bar=gir

... it will print this output:

The value of -f/--foo-bar is gir.

The $options array is keyed on what we want as the option name, and each element is an array of option definition keys:

• 'long': The long form of the option, which is passed by prefixing it with two dashes at the command line. A long-form param value is passed by following it with an equals sign and the value; e.g., --foo-bar=some_value. Leave this empty if we do not want a long-form option.

• 'short': The short form of the option, which is passed by prefixing it with one dash at the command line. A short-form param value is passed by following it with a space and the value; e.g., -f some_value. Leave this empty if we do not want a short-form option.

• 'param': Is a a param value required for the option, is it optional, or is it disallowed? Use Option::PARAM_REQUIRED to force a param value to be passed, Option::PARAM_OPTIONAL to allow a value to be passed or not, or Option::PARAM_REJECTED to disallow any value from being passed.

• 'multi': Is the option allowed to be passed multiple times in the same command? E.g., "-f foo -f bar -f zim" will make the option value an array with three entries: ['foo', 'bar', 'zim'].

• 'default': The default value for the option if it is not passed.

After we have defined the options and passed them at the command line, we can read them from the $getopt object as magic read-only properties. Thus, for the above option named as 'foo_bar', we can retrieve its value by using $this->getopt->foo_bar.