- print_r: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$str = 'value that I {want}, vs value "I do {NOT} want" ';
//$str = preg_replace("/\".*\"/U","",$str);
preg_match_all("(\"|').*?\1(*SKIP)(*FAIL)|\{(?:[^{}]|(?R))*\}",$str,$matches);
print_r($matches);