--- /dev/null
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Console\Core\Command\HelpCommand.
+ */
+
+namespace Drupal\Console\Core\Command;
+
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputDefinition;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Command\Command;
+use Drupal\Console\Core\Command\Shared\CommandTrait;
+use Drupal\Console\Core\Style\DrupalStyle;
+use Drupal\Console\Core\Helper\DescriptorHelper;
+
+/**
+ * HelpCommand displays the help for a given command.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class HelpCommand extends Command
+{
+ use CommandTrait;
+
+ private $command;
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function configure()
+ {
+ $this->ignoreValidationErrors();
+
+ $this
+ ->setName('help')
+ ->setDefinition($this->createDefinition())
+ ->setDescription($this->trans('commands.help.description'))
+ ->setHelp($this->trans('commands.help.help'));
+ }
+
+ /**
+ * Sets the command.
+ *
+ * @param $command
+ * The command to set
+ */
+ public function setCommand($command)
+ {
+ $this->command = $command;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function execute(InputInterface $input, OutputInterface $output)
+ {
+ $io = new DrupalStyle($input, $output);
+
+ if (null === $this->command) {
+ $this->command = $this->getApplication()->find($input->getArgument('command_name'));
+ }
+
+ if ($input->getOption('xml')) {
+ $io->info($this->trans('commands.help.messages.deprecated'), E_USER_DEPRECATED);
+ $input->setOption('format', 'xml');
+ }
+
+ $helper = new DescriptorHelper();
+ $helper->describe(
+ $io,
+ $this->command,
+ [
+ 'format' => $input->getOption('format'),
+ 'raw_text' => $input->getOption('raw'),
+ 'command_name' => $input->getArgument('command_name'),
+ 'translator' => $this->getApplication()->getTranslator()
+ ]
+ );
+
+ $this->command = null;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ private function createDefinition()
+ {
+ return new InputDefinition(
+ array(
+ new InputArgument('command_name', InputArgument::OPTIONAL, $this->trans('commands.help.arguments.command_name'), 'help'),
+ new InputOption('xml', null, InputOption::VALUE_NONE, $this->trans('commands.help.options.xml')),
+ new InputOption('raw', null, InputOption::VALUE_NONE, $this->trans('commands.help.options.raw')),
+ new InputOption('format', null, InputOption::VALUE_REQUIRED, $this->trans('commands.help.options.format'), 'txt'),
+ )
+ );
+ }
+}