I'am trying to use regular expression to get just file name from URL for example:
$link = "http://localhost/website/index.php";
$pattern = '/.*?\.php';
preg_match($pattern, $link, $matches);
but it returns "//localhost/website/index.php" instead of "index".
Does your code even run? You haven't used any delimiters...
With preg_match, you could use a negated class instead, because / matches the first / then .*? will match all the characters up to .php... and if you want to get only index, it would be simplest to use a capture group like so:
$link = "http://localhost/website/index.php";
$pattern = '~([^/]+)\.php~';
preg_match($pattern, $link, $matches);
echo $matches[1]; # Get the captured group from the array $matches
Or you can simply use the basename function:
echo basename($link, ".php");
| instead, or - or # or @ etc. If I had used / as delimiter however, I would have had to use the pattern like this: /([^\/]+)\.php/ (i.e. I would need to escape all the / in the pattern). I usually use ~ if my pattern has any /, so that I don't need to escape them, and this symbol is quite rare, so all the better to use.
I think you would be much better off using a function dedicated to the purpose, rather than a custom regular expression.
Since the example you provided is actually a URL, you could use the parse_url function:
http://php.net/manual/en/function.parse-url.php
You should also look at the pathinfo (well done PHP on the naming consistency there!):
http://php.net/manual/en/function.pathinfo.php
You could then do something like this:
$url = 'http://localhost/path/file.php';
$url_info = parse_url($url);
$full_path = $url_info['path'];
$path_info = pathinfo($full_path);
$file_name = $path_info['filename'] . '.' . $path_info['extension'];
print $file_name; // outputs "file.php"
This might seem more verbose than using regular expressions, but it likely to be much faster and, more importantly, much more robust.
