Using regex to find IDENTIFIER in URL and return as a string

Question

I've got a PHP script that does batch wgets from a database, but need to create a mechanism to generate folders so I can loop it all to save each file in its own folder...

Can one use regex to find the IDENTIFIER (which can be anything/any length, sometimes with underscores, sometimes with hyphens other times not) in following URL or is there some other way? I have no idea about regex...

http://cdn.blah.com/mp4/IDENTIFIER/somefile.mp4

For example, can one find IDENTIFIER and return it as a string? That way I can pass it to write "wget -O /somedir/" . $IDENTIFIER . "/"; and that would help greatly!

Any help very appreciated. Thanks!

Answer 1

You can get the identifier using a combination of dirname() and basename():

$url = 'http://cdn.blah.com/mp4/IDENTIFIER/somefile.mp4';
$identifier = basename(dirname($url));

Answer 2

I dunno anything about PHP but I notice that

/.*\/([^/]+)\/[^/]+/.exec(s)

pops IDENTIFIER right out for you.

edit: a very brief Google suggests the PHP equivalent would be

<?php
$subject = "http://cdn.blah.com/mp4/IDENTIFIER/somefile.mp4";
$pattern = "/.*\/([^/]+)\/[^/]+/";
preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE);
print_r($matches);
?>