使用正则表达式对旧php版本进行网址验证

Question

Note : I'm using an older PHP version so FILTER_VALIDATE_URL is not available at this time.

After many many searches I am still unable to find the exact answer that can cover all URL structure possibilities but at the end I'm gonna use this way:

I'm using the following function

1) Function to get proper scheme

function convertUrl ($url){
    $pattern = '#^http[s]?://#i';
    if(preg_match($pattern, $url) == 1) { // this url has proper scheme
        return $url;
    } else {
        return 'http://' . $url;
    }
}

2) Conditional to check if it is a URL or not

if (preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i", $url)) {
  echo "URL is valid";
}else {
  echo "URL is invalid<br>";
}

Guess What!? It works so perfect for all of these possibilities:

$url = "google.com";
$url = "www.google.com";
$url = "http://google.com";
$url = "http://www.google.com";
$url = "https://google.com";
$url = "https://www.codgoogleekarate.com";
$url = "subdomain.google.com";
$url = "https://subdomain.google.com";

But still have this edge case

$url = "blahblahblahblah";

The function convertUrl($url) will convert this to $url = "http://blahblahblahblah"; then the regex will consider it as valid URL while it isn't!!

How can I edit it so that it won't pass a URL with this structure http://blahblahblahblah

Answer 1

如果要验证Internet网址 ，请在正则表达式中添加检查点是否包含点（。）字符。

Note: http://blahblahblah is a valid url as is http://localhost

Answer 2

Try this:

if (preg_match("/^(([\w]+:)?\/\/)?(([\d\w]|%[a-fA-f\d]{2,2})+(:([\d\w]|%[a-fA-f\d]{2,2})+)?@)?([\d\w][-\d\w]{0,253}[\d\w]\.)+[\w]{2,4}(:[\d]+)?(\/([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)*(\?(&?([-+_~.\d\w]|%[a-fA-f\d]{2,2})=?)*)?(#([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)?$/", $url)) {
  echo "URL is valid";
}else {
  echo "URL is invalid<br>";
}