Regular expression for validation of a facebook page url

Question

I need to validate the facebook page url which should not consider http/https or www given or not?

I mean the following should be accepted or valid:

www.facebook.com/ABCDE
facebook.com/ABCDE
http://www.facebook.com/ABCDE
https://www.facebook.com/ABCDE

And following should not be accepted or invalid:

http://www.facebook.com/   => User name/page name not given
http://www.facebook.com/ABC   => User name/page name should have the minimum length of 5.

For the above requirement I'd made following regular expression, but it is not checking the User Name or Page Name which is the only problem. Rest is working fine:

/^(https?:\/\/)?((w{3}\.)?)facebook.com\/(([a-z\d.]{5,})?)$/

I am very new to Regular Expression, so don't have much idea about it.

Any type of help would be appreciable.

Thanks in advance.

Answer 1

parse_url() can help you with that.

<?php

$array = array(
    "www.facebook.com/ABCDE",
    "facebook.com/ABCDE",
    "http://www.facebook.com/ABCDE",
    "https://www.facebook.com/ABCDE",
    "http://www.facebook.com/",
    "http://www.facebook.com/ABC"
);

foreach ($array as $link) {
    if (strpos($link, "http") === false) {
        $link = "http://" . $link; //parse_url requires a valid URL. A scheme is needed. Add if not already there.
    }
    $url = parse_url($link);
    if (!preg_match("/(www\.)?facebook\.com/", $url["host"])) {
        //Not a facebook URL
        echo "FALSE!";
    }
    elseif (strlen(trim($url["path"], "/")) < 5) {
        //Trailing path (slashes not included) is less than 5
        echo "FALSE!";
    }
    else {
        //None of the above
        echo "TRUE";
    }
    echo "<br>";
}