composer/src/Composer/Command/GlobalCommand.php

<?php declare(strict_types=1);

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Composer\Command;

use Composer\Factory;
use Composer\Pcre\Preg;
use Composer\Util\Filesystem;
use Composer\Util\Platform;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Completion\CompletionInput;
use Symfony\Component\Console\Completion\CompletionSuggestions;
use Symfony\Component\Console\Input\InputInterface;
use Composer\Console\Input\InputArgument;
use Symfony\Component\Console\Input\StringInput;
use Symfony\Component\Console\Output\OutputInterface;

/**
 * @author Jordi Boggiano <j.boggiano@seld.be>
 */
class GlobalCommand extends BaseCommand
{
    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
    {
        $application = $this->getApplication();
        if ($input->mustSuggestArgumentValuesFor('command-name')) {
            $suggestions->suggestValues(array_filter(array_map(function (Command $command) {
                return $command->isHidden() ? null : $command->getName();
            }, $application->all())));

            return;
        }

        if ($application->has($commandName = $input->getArgument('command-name'))) {
            $input = $this->prepareSubcommandInput($input, true);
            $input = CompletionInput::fromString($input->__toString(), 2);
            $command = $application->find($commandName);
            $command->mergeApplicationDefinition();

            $input->bind($command->getDefinition());
            $command->complete($input, $suggestions);
        }
    }

    /**
     * @return void
     */
    protected function configure(): void
    {
        $this
            ->setName('global')
            ->setDescription('Allows running commands in the global composer dir ($COMPOSER_HOME).')
            ->setDefinition(array(
                new InputArgument('command-name', InputArgument::REQUIRED, ''),
                new InputArgument('args', InputArgument::IS_ARRAY | InputArgument::OPTIONAL, ''),
            ))
            ->setHelp(
                <<<EOT
Use this command as a wrapper to run other Composer commands
within the global context of COMPOSER_HOME.

You can use this to install CLI utilities globally, all you need
is to add the COMPOSER_HOME/vendor/bin dir to your PATH env var.

COMPOSER_HOME is c:\Users\<user>\AppData\Roaming\Composer on Windows
and /home/<user>/.composer on unix systems.

If your system uses freedesktop.org standards, then it will first check
XDG_CONFIG_HOME or default to /home/<user>/.config/composer

Note: This path may vary depending on customizations to bin-dir in
composer.json or the environmental variable COMPOSER_BIN_DIR.

Read more at https://getcomposer.org/doc/03-cli.md#global
EOT
            )
        ;
    }

    /**
     * @throws \Symfony\Component\Console\Exception\ExceptionInterface
     */
    public function run(InputInterface $input, OutputInterface $output): int
    {
        if (!method_exists($input, '__toString')) {
            throw new \LogicException('Expected an Input instance that is stringable, got '.get_class($input));
        }

        // extract real command name
        $tokens = Preg::split('{\s+}', $input->__toString());
        $args = array();
        foreach ($tokens as $token) {
            if ($token && $token[0] !== '-') {
                $args[] = $token;
                if (count($args) >= 2) {
                    break;
                }
            }
        }

        // show help for this command if no command was found
        if (count($args) < 2) {
            return parent::run($input, $output);
        }

        $input = $this->prepareSubcommandInput($input);

        return $this->getApplication()->run($input, $output);
    }

    private function prepareSubcommandInput(InputInterface $input, bool $quiet = false): StringInput
    {
        // The COMPOSER env var should not apply to the global execution scope
        if (Platform::getEnv('COMPOSER')) {
            Platform::clearEnv('COMPOSER');
        }

        // change to global dir
        $config = Factory::createConfig();
        $home = $config->get('home');

        if (!is_dir($home)) {
            $fs = new Filesystem();
            $fs->ensureDirectoryExists($home);
            if (!is_dir($home)) {
                throw new \RuntimeException('Could not create home directory');
            }
        }

        try {
            chdir($home);
        } catch (\Exception $e) {
            throw new \RuntimeException('Could not switch to home directory "'.$home.'"', 0, $e);
        }
        if (!$quiet) {
            $this->getIO()->writeError('<info>Changed current directory to '.$home.'</info>');
        }

        // create new input without "global" command prefix
        $input = new StringInput(Preg::replace('{\bg(?:l(?:o(?:b(?:a(?:l)?)?)?)?)?\b}', '', $input->__toString(), 1));
        $this->getApplication()->resetComposer();

        return $input;
    }

    /**
     * @inheritDoc
     */
    public function isProxyCommand(): bool
    {
        return true;
    }
}