custom drush command

download_backdrop.drush.inc

<?php
/**
 * @file
 * Download Backdrop CMS with drush.
 */

/**
 * Implements hook_drush_command().
 */
function backdrop_download_backdrop_drush_command() {
  $items = array();
  $items['backdrop-download'] = array(
  'description' => 'Download Backdrop CMS contrib modules.',
  'callback' => 'backdrop_download_backdrop',
  'hidden' => TRUE,
  'arguments' => array(
    'module-name' => array('The name of the module(s) you would like to download.'),
  ),
  'options' => array(
    'select' => 'Select the version of the module.',
    'path' => "Specify a path to download backdrop source code to.",
  ),
  'required-arguments' => TRUE,
  'help' => "Download Backdrop CMS source code.",
  'aliases' => array('dlb', 'dl-backdrop'),
  'bootstrap' => \Drush\Boot\BackdropBoot::BOOTSTRAP_SITE,
  );

  return $items;
}

/**
 * Command callback. Download a Backdrop CMS.
 *
 * @param $projects
 *  Array of Backdrop CMS contrib projects to download.
 */
function backdrop_download_backdrop() {
  $package_handler = backdrop_download_backdrop_validate();
  if (!$package_handler) {
    return;
  }
  $projects = func_get_args();
  $options = drush_get_option('select', '');
  $download_location = drush_get_option('path', '.');

  if (!empty($options)) {
    drush_print_r("\t\033[32mChoose one of the available releases for $projects[0] \n");
    // get available releases.
    $tags = backdrop_command_get_tags(
      "https://updates.backdropcms.org/release-history/$projects[0]/1.x"
    );

    $project_path = backdrop_download_backdrop_get_path($download_location);

    for($i = 0; $i < count($tags->releases->release); $i++) {
      $version = (string) $tags->releases->release[$i]->version;
      drush_print_r("\t\t [$i] \t:\t " . $version);
    }
    // get users's menu selection
    $handle = fopen ("php://stdin","r");
    print("\n\tSelect one [0]: ");
    print("\033[0m");
    $selection = fgets($handle);
    $selection = trim($selection);
    // default to latest release if user just hits enter.
    if (empty($selection)) {
      $selection = 0;
    }

    $sel_url = $tags->releases->release[(int) $selection]->download_link;

    // download verssion of the project user selected.
    exec(
      "wget --quiet --O $project_path/$projects[0].zip $sel_url"
    );
    // Extract the zip file.
    exec(
      "unzip $project_path/$projects[0].zip -d $project_path"
    );
    // Remove the zip file.
    exec(
      "rm $project_path/$projects[0].zip"
    );
    backdrop_download_backdrop_dl_outcome($project_path, $projects[0]);
  }
  else {
    foreach ($projects as $project) {
      // Downloading backdrop itself is a special case.
      // TODO: Downloading backdrop itself does not currently work since
      //   the backdrop drush command hooks are only picked up once a valid
      //   backdrop installation is detected, so we have a chicken and the egg
      //   problem here.
      $html = backdrop_download_backdrop_from_github(
        "https://github.com/backdrop/backdrop/releases/latest"
      );

      $html = explode("\"", $html);
      $url = $html[1];
      $latest = explode('/', $url);
      $latest = array_reverse($latest);

      // Get the core zip file.
      exec(
        "wget --quiet -O . https://github.com/$project/$project/releases/download/$latest[0]/backdrop.zip"
      );
      // Extract the zip file.
      exec(
        "unzip backdrop.zip"
      );
      // Remove the zip file.
      exec(
        "rm backdrop.zip"
      );
      backdrop_download_backdrop_dl_outcome($download_location, 'Backdrop CMS');
    }
  }
}

/**
 * Helper function for backdrop_command_pm_download().
 *
 * Gets the url for the github repo of the contrib module.
 */
function backdrop_download_backdrop_from_github($url) {
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 1);
  $content = curl_exec($ch);
  curl_close($ch);
  return $content;
}

/**
 * Helper function for --select option for download command.
 * Gets the tags for a project.
 */
function backdrop_download_backdrop_get_tags($url) {
  $xml = simplexml_load_file($url);
  return $xml;
}

/**
 * Get the path to where to store backdrop.
 * Defaults to current directory.
 *
 * @param
 *   string $path
 * @return
 *   string path to download backdrop source to.
 */
function backdrop_download_backdrop_get_path($path = '.') {
  $project_path = BACKDROP_ROOT . '/layouts';
  return $project_path;
}

/**
 * Determine success or failure of drush dl command and give the user some
 * relevent feedback.
 * @param string $module_install_location
 *  String directory path where module should end up.
 *
 * @param string $project
 *  Project name.
 */
function backdrop_download_backdrop_dl_outcome($module_install_location, $project) {
  if (file_exists($module_install_location)) {
    print "\n\t\033[32m Success: \033[0m Project $project downloaded to $module_install_location.\n\n";
  }
  else {
    print "\n\t\033[31m Error: \033[0m Project $project could not be found.\n\n";
  }
}

/**
 * Command backdrop_download_backdrop validate function.
 */
function backdrop_download_backdrop_validate() {
  // Check that wget command exists. Disable possible output.
  $debug = drush_get_context('DRUSH_DEBUG');
  drush_set_context('DRUSH_DEBUG', FALSE);
  $success = drush_shell_exec('wget --version');
  drush_set_context('DRUSH_DEBUG', $debug);
  if (!$success) {
    return drush_set_error(
      'DRUSH_SHELL_COMMAND_NOT_FOUND',
      dt("\n\t\033[1mwget\033[0m executable not found.
      Downloading projects with drush depends on wget consider installing wget on your system.\n")
    );
  }
  return TRUE;
}