$re = '/(?:"[^"\s]*"[^"]*)*("\S*\s[^"]*")/';
$str = 'adb shell am startservice -n fooApp/barService -a INVOKE --es "key" "key1" --es "value" "value 2 has spaces"';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php