chmod

Write text to a file (overwrite if exists)

	$output_text = "Hello";
	file_put_contents("files/output_filename.txt", $output_text);			//(Will overwrite an existing file)

Write text to a file (create or append)

	$output_text = "Hello";
	file_put_contents("files/output_filename.txt", $output_text . PHP_EOL, FILE_APPEND | LOCK_EX);			//(Create or append if exists)