$re = '/<input value="(\w*)" name="A3">/';
$str = '<input value="AAA" name="A1"> <input value="BBB" name="A2"> <input value="TEXT" name="A3">';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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