Simple PHP Console

Console.php

<?php
// @codingStandardsIgnoreFile

class Console
{
    /**
     * Available Commands
     *
     * Key i command name, value is callable spec
     *
     * @var array
     *
     * @access protected
     */
    protected $commands = [];

    /**
     * Resolves a spec to a calable
     *
     * @var callable
     *
     * @access protected
     */
    protected $resolver;

    /**
     * Name of executable
     *
     * @var string
     *
     * @access protected
     */
    protected $executable;

    /**
     * Name of command
     *
     * @var string
     *
     * @access protected
     */
    protected $command;

    /**
     * Arguments to pass to command
     *
     * @var array
     *
     * @access protected
     */
    protected $args = [];


    /**
     * Constructor
     *
     * Create a new Console application
     *
     * @param array    $commands available commands
     * @param callable $resolver optional resolver
     *
     * @access public
     */
    public function __construct(
        array $commands,
        callable $resolver = null
    ) {
        $this->commands = $commands;
        $this->resolver = $resolver;
    }

    /**
     * Invoke a command
     *
     * Invoke a command by name with argv
     *
     * @param array $args should be argv probably
     *
     * @return bool
     *
     * @access public
     */
    public function __invoke(array $args)
    {
        $this->init($args);

        if (! $this->isValid()) {
            $this->usage();
            return false;
        }

        return $this->execute();
    }

    /**
     * Initialize
     *
     * Setup state based on argv
     *
     * @param array $args input arguments
     *
     * @return null
     *
     * @access protected
     */
    protected function init(array $args)
    {
        $this->executable = array_shift($args);
        $this->command    = array_shift($args);
        $this->args       = (array) $args;
    }

    /**
     * Is Command valid?
     *
     * Check if input was valid
     *
     * @return bool
     *
     * @access protected
     */
    protected function isValid()
    {
        return (null !== $this->command)
            && array_key_exists($this->command, $this->commands);
    }

    /**
     * Actually execute command
     *
     * @return mixed
     *
     * @access protected
     */
    protected function execute()
    {
        $spec    = $this->commands[$this->command];
        $command = $this->resolve($spec);
        return call_user_func_array($command, $this->args);
    }

    /**
     * Resolve spec
     *
     * @param mixed $spec spec to resolve to callable
     *
     * @return callable
     *
     * @access protected
     */
    protected function resolve($spec)
    {
        if (! $this->resolver) {
            return $spec;
        }
        return call_user_func($this->resolver, $spec);
    }

    /**
     * Print usage
     *
     * @return null
     *
     * @access protected
     */
    protected function usage()
    {
        echo 'Usage:' . PHP_EOL;
        foreach (array_keys($this->commands) as $command) {
            echo $this->executable . ' ' . $command . PHP_EOL;
        }
    }
}

my-app.php

#!/usr/bin/env php
<?php
// @codingStandardsIgnoreFile


/**
 * Some Commands
 */

class HelloWorld
{
    public function __invoke($name = 'World')
    {
        echo "Hello $name" . PHP_EOL;
        return true;
    }
}

class ByeWorld
{
    public function __invoke($name = 'World')
    {
        echo "Bye $name" . PHP_EOL;
        return true;
    }
}


/**
 *  Simple resolver
 */
$resolver = function ($spec) {
    return new $spec;
};



/**
 * Create an application
 */
$console = new Console(
    [
        'hi'  => HelloWorld::class,
        'bye' => ByeWorld::class
    ],
    $resolver
);


// Execute based on input and exit
$console($argv) ? exit(0) : exit(1);