core-bundle/src/Resources/contao/classes/Backend.php
public static function handleRunOnce()
	{
		try
		{
			$files = System::getContainer()->get('contao.resource_locator')->locate('config/runonce.php', null, false);
		}
		catch (\InvalidArgumentException $e)
		{
			return;
		}

		foreach ($files as $file)
		{
			try
			{
				include $file;
			}
			catch (\Exception $e) {}

			$strRelpath = StringUtil::stripRootDir($file);

			if (!unlink($file))
			{
				throw new \Exception("The file $strRelpath cannot be deleted. Please remove the file manually and correct the file permission settings on your server.");
			}

			System::log("File $strRelpath ran once and has then been removed successfully", __METHOD__, TL_GENERAL);
		}
	}
public static function handleRunOnce()
	{
		try
		{
			$files = System::getContainer()->get('contao.resource_locator')->locate('config/runonce.php', null, false);
		}
		catch (\InvalidArgumentException $e)
		{
			return;
		}

		foreach ($files as $file)
		{
			try
			{
				include $file;
			}
			catch (\Exception $e) {}

			$strRelpath = StringUtil::stripRootDir($file);

			if (!unlink($file))
			{
				throw new \Exception("The file $strRelpath cannot be deleted. Please remove the file manually and correct the file permission settings on your server.");
			}

			System::log("File $strRelpath ran once and has then been removed successfully", __METHOD__, TL_GENERAL);
		}
	}
Handle "runonce" files

@throws \Exception