Question

I am looking for a regular expression using preg_match_all in PHP 5 that would allow me to split a string by commas, so long as the commas do not exist inside single quotes, allowing for escaped single quotes. Example data would be:

(some_array, 'some, string goes here','another_string','this string may contain "double quotes" but, it can\'t split, on escaped single quotes', anonquotedstring, 83448545, 1210597346 + '000', 1241722133 + '000')

This should produce a match that looks like this:

(some_array

'some, string goes here'

'another_string'

'this string may contain "double quotes" but, it can\'t split, on escaped single quotes'

 anonquotedstring

 83448545

 1210597346 + '000'

 1241722133 + '000')

I’ve tried many, many regexes… My current one looks like this, although it doesn’t match 100% correctly. (It still splits some commas inside single quotes.)

"/'(.*?)(?<!(?<!\\\)\\\)'|[^,]+/"

Answer 1

Have you tried str_getcsv? It does exactly what you need without a regular expression.

$result = str_getcsv($str, ",", "'");

You can even implement this method in PHP versions older than 5.3, mapping to fgetcsv with this snippet from a comment in the docs:

if (!function_exists('str_getcsv')) {

    function str_getcsv($input, $delimiter = ',', $enclosure = '"', $escape = null, $eol = null) {
        $temp = fopen("php://memory", "rw");
        fwrite($temp, $input);
        fseek($temp, 0);
        $r = fgetcsv($temp, 4096, $delimiter, $enclosure);
        fclose($temp);
        return $r;
    }

}