PHP: comparing URIs which differ in percent-encoding

In PHP, I want to compare two relative URLs for equality. The catch: URLs may differ in percent-encoding, e.g.

• /dir/file+file vs. /dir/file%20file
• /dir/file(file) vs. /dir/file%28file%29
• /dir/file%5bfile vs. /dir/file%5Bfile

According to RFC 3986, servers should treat these URIs identically. But if I use == to compare, I'll end up with a mismatch.

So I'm looking for a PHP function which will accepts two strings and returns TRUE if they represent the same URI (dicounting encoded/decoded variants of the same char, upper-case/lower-case hex digits in encoded chars, and + vs. %20 for spaces), and FALSE if they're different.

I know in advance that only ASCII chars are in these strings-- no unicode.

function uriMatches($uri1, $uri2)
{
    return urldecode($uri1) == urldecode($uri2);
}

echo uriMatches('/dir/file+file', '/dir/file%20file');      // TRUE
echo uriMatches('/dir/file(file)', '/dir/file%28file%29');  // TRUE
echo uriMatches('/dir/file%5bfile', '/dir/file%5Bfile');    // TRUE

urldecode