$re = '/(?<=,")[^"\n]*(?=",)|(?<=,)(?!")[^,\n]*(?<!")(?=,)/m';
$str = '"0x00000000","What do you want to eat? fish, meat or\\n eggs?",""
"0x00030002","What do you want to eat?",""
0x00030002,What do you want to eat?,
"0x00030002","What do you, want to eat?",""
0x00030002,What do "you want" to eat?,
"0x00030002,What do you want to eat?,",?,
"0x00030002","What do you want to eat?,"
0x00030002 ,What do you want to eat?",
Note \\n is included in [^"\\n] merely to test the regex against multiple strings.';
preg_match_all($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