How to add http:// if it's not exists in the URL?

Question

Hi,

How to add http:// to the url if there isn't a http:// or https:// or ftp:// ?

Example:

addhttp("google.com"); // http://google.com
addhttp("www.google.com"); // http://www.google.com
addhttp("google.com"); // http://google.com
addhttp("ftp://google.com"); // ftp://google.com
addhttp("https://google.com"); // https://google.com
addhttp("http://google.com"); // http://google.com
addhttp("rubbish"); // http://rubbish

Answer 1

Try this. Not watertight*, but might be good enough:

function addhttp($url) {
    if (!preg_match("@^[hf]tt?ps?://@", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

*: that is, prefixes like "fttps://" are treated as valid.

Answer 2

nickf solution modified:

function addhttp($url) {
    if (!preg_match("@^https?://@i", $url) && !preg_match("@^ftps?://@i", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

Answer 3

A modified version of @nickf code:

function addhttp($url) {
    if (!preg_match("~^(?:f|ht)tps?://~i", $url)) {
        $url = "http://" . $url;
    }
    return $url;
}

Recognizes ftp://, ftps://, http:// and https:// in a case insensitive way.

Answer 4

Scan the string for ://, if it does not have it, prepend http:// to the string.., everything else just use the string as is.

This will work unless you have rubbish input string.

Answer 5

Simply check if there is a protocol (delineated by "://") and add "http://" if there isn't.

if (false === strpos($url, '://')) {
    $url = 'http://' . $url;
}