Question

Due to limitations in my script, I’ve come across a problem where I need to make sure a string matches one of two regex patterns while only calling preg_match() once.

Here’s some of my code:

public static function get_file_host_from_link($link)
{
    foreach(Filehosts::$file_hosts as $key => $val)
    {
        if(preg_match("#{$val["regex"]}#", $link))
        {
            // We have a match, return this file host information
            return $key;
        }
    }
    // We've looped through all the file hosts and it hasn't matched,
    // return false
    return false;
}

Now, the problem with matching Fileserve.com URL’s is that there can be two types of valid URL structures. One of them is:

http://www.fileserve.com/file/aHd8AHD

and the other:

http://www.fileserve.com/file/zR8VJVM/file_name.zip

At the moment, I can match the first structure perfectly fine using this regex: ^http://www.fileserve.com/file/[a-zA-Z0-9]+$ but I also need to match the other URL structure using something like this: http://www.fileserve.com/[a-zA-Z0-9]+/[a-zA-Z0-9_-\.]+$. How can I do this with my existing code and only calling preg_match() once? I thought about something like this:

(^http://www.fileserve.com/file/[a-zA-Z0-9]+$|http://www.fileserve.com/[a-zA-Z0-9]+/[a-zA-Z0-9_-\.]+$)

which to my knowledge means “match the first regex pattern OR the second one”, but I have no idea if that’d work.

Thanks!

Answer 1

The following should work:

^http://www.fileserve.com/file/[a-zA-Z0-9]+(/[-a-zA-Z0-9_\.]+)?$

The ? after everything in the parentheses makes it optional.

Also, note that the character class [a-zA-Z0-9_-\.] is invalid because - specifies a range unless it is escaped or at the start.

You either want [-a-zA-Z0-9_\.] or [a-zA-Z0-9_\-\.] (I used the first in my answer).