Simple script to load localizations from the Main storyboards string into a new one after refactoring some view controllers into a new storyboard using Xcode 9.

load_localizations_after_refactor.php

<?php

/*
Make sure to localize the new storyboard files using Xcode and that should be used as the destination.
*/

$src = file($argv[1]);
$dst = file($argv[2]);

$modified_file = array();

$new_translations = array();

foreach($src as $line) {
  if (preg_match("/\"(.*)\" = \"(.*)\";/",$line,$matches)) {
    $new_translations[$matches[1]] = $matches[2];
  }
}

foreach($dst as $line) {
  if (preg_match("/\"(.*)\" = \"(.*)\";/",$line,$matches)) {
    if (isset($new_translations[$matches[1]])) {
      $modified_file[] = '"'.$matches[1].'" = "'.$new_translations[$matches[1]].'";'."\n";
    } else {
      echo "Cannot find : ".$matches[1]." , ".$matches[2]."\n";
      $modified_file[] = $line;
    }
  } else {
    $modified_file[] = $line;
  }
}

file_put_contents("new/".$argv[2],implode("",$modified_file));