Regex matching to a terminator plus a variable character sequence

Question

Sorry to bother, I feel permanently lost when it comes to regex...

I have to match a string which occurs in a longer sequence of hex-values. My test-string is this:

BF1301020302000017BF1301030101010300FF6ABF130201010300FFC0BF1303010303030100FF98

Pattern is this:

• starts with BF13
• followed by an unknown amount of "01", "02" or "03" repetitions (\w\w)
• 00 marks the termination of the sequence between BF13 and 00
• after the 00-terminator, there are always 4 additional chars

I tried BF13(\w\w)+?00(\w\w){1} but it's obviously wrong.

The test-string is supposed to match and output these values:

• BF1301020302000017
• BF1301030101010300FF6A
• BF130201010300FFC0
• BF1303010303030100FF98

Thanks, guys!

Answer 1

This one will do the job :

BF13(?:0[123])+00[A-Z0-9]{4}

Explanation

BF13 BF13 literally

(?:...)+ Followed by something (non capturing group) at least one time (+)

0[123] a zero followed by 1, 2 or 3

00 Followed by 00

[A-Z0-9]{4} Followed by uppercase char or a digit 4 times

RegExp Demo

Sample PHP code Test online

$re = '/BF13(?:0[123])+00[A-Z0-9]{4}/';
$str = 'BF1301020302000017BF1301030101010300FF6ABF130201010300FFC0BF1303010303030100FF98';

preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);

foreach ($matches as $val) {
    echo "matched: " . $val[0] . "\n";
}