Small script to download and format into JSON the IANA Languages subtag registry

iana_langs.php

<?php

$iana_lang_subtags_file = 'iana_lang_subtags.txt';
$iana_lang_subtags_url = 'https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry';
$iana_lang_subtags_json = 'iana_lang_subtags.json';
$update = false; if(isset($argv[1])) $update = true;
$langs = new stdClass;
$langs->metadata = new stdClass;

$uri = $iana_lang_subtags_file;
if(!file_exists($iana_lang_subtags_file) || $update){
  $uri = $iana_lang_subtags_url;
  $update = true;
}
// fetch list
$raw = file_get_contents($uri);
// save to file
if($update) file_put_contents($iana_lang_subtags_file, $raw);

$langs_strings = explode('%%', $raw);

$langs->metadata->comment = trim(array_shift($langs_strings));
$structure_langs = new stdClass;
$structure_langs->tags = new stdClass;
$structure_langs->total = 0;
foreach($langs_strings as $lang_string){
  $lang = new stdClass;
  //$lang_aux = new stdClass;
  foreach(explode("\n", $lang_string) as $line){
    $line=trim($line);
    if($line=="") continue;
    $item = explode(": ",$line);

    if(  count($item) > 1  ){
      
      list($name,$value)=$item;
      
      $name = str_replace(["-"], ["_"], trim(strtolower($name)));
      
      if(strpos($name," ")===false){
        $lang->$name[] = trim($value);
        $last=$name;
      }else{
        $lang->$last[]=$line;
      }
    }else{
      $lang->$last[]=$item[0];
    }
  }
  
  foreach($lang as $prop => &$val){
    //var_dump($val[0]);
    $val = implode("\n",$val);
    if(!isset($structure_langs->tags->$prop)) $structure_langs->tags->$prop = 0;
    ++$structure_langs->tags->$prop;
  }
  ++$structure_langs->total;
  //var_dump($lang);

  $langs->content[] = $lang;
}
$structure_tags = new stdClass;
foreach($structure_langs->tags as $tag => $value){
  
  if($structure_langs->total == $value){
    $structure_tags->$tag = "always-present";
  }else{
    $structure_tags->$tag = "optional";
  }
}
$langs->metadata->structure = $structure_tags;

file_put_contents($iana_lang_subtags_json, json_encode($langs, JSON_PRETTY_PRINT));