List all free fontawesome icons

get_free_fa_icons.php

<?php

function proc_fa($page) {
  $curl = curl_init($page);
  curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
  $tmp = curl_exec($curl);
  curl_close($curl);
  preg_match('/window.__inline_data__ =(.*?)<\/script>/s', $tmp, $match);
  $res = json_decode($match[1]);

  $prepend = ",'";
  $append = "'";

  foreach ($res[1] as $rex) {
    foreach ($rex as $key => $value) {
      if (!isset($value->attributes)) { continue; }
      foreach ($value->attributes->membership->free as $member) {
        $ico = (isset($prepend)?$prepend:'');
        switch ($member) {
          case 'brands':
            $ico .= "fab fa-";
            break;
          case 'solid':
            $ico .= "fas fa-";
            break;
          case 'regular':
            $ico .= "far fa-";
            break;
          default:
            echo ">> ERR-001: ".$member.PHP_EOL;
            die();
        }
        $ico .= $value->attributes->id."'".PHP_EOL;
        echo $ico;
      }
    }
  }
}

$url = 'https://fontawesome.com/cheatsheet/free/';

proc_fa($url);

?>