验证网址并检查url是域名还是子域名

Question

我需要验证网址并检查输入的URL是域名还是子域名。
我试过一个解决方案，它的工作，但在某些情况下，它失败了。

function subDomain(url) 
{ 

    // IF THERE, REMOVE WHITE SPACE FROM BOTH ENDS 
    url = url.replace(new RegExp(/^\s+/),""); // START 
    url = url.replace(new RegExp(/\s+$/),""); // END 

    // IF FOUND, CONVERT BACK SLASHES TO FORWARD SLASHES 
    url = url.replace(new RegExp(/\\/g),"/"); 

    // IF THERE, REMOVES 'http://', 'https://' or 'ftp://' FROM THE START 
    //url = url.replace(new RegExp(/^http\:\/\/|^https\:\/\/|^ftp\:\/\//i),""); 

    // IF THERE, REMOVES 'www.' FROM THE START OF THE STRING 
    url = url.replace(new RegExp(/^www\./i),""); 

    // REMOVE COMPLETE STRING FROM FIRST FORWARD SLASH ON 
    url = url.replace(new RegExp(/\/(.*)/),""); 

    // REMOVES '.??.??' OR '.???.??' FROM END - e.g. '.CO.UK', '.COM.AU' 
    if (url.match(new RegExp(/\.[a-z]{2,3}\.[a-z]{2}$/i))) { 
     url = url.replace(new RegExp(/\.[a-z]{2,3}\.[a-z]{2}$/i),""); 

    // REMOVES '.??' or '.???' or '.????' FROM END - e.g. '.US', '.COM', '.INFO' 
    } else if (url.match(new RegExp(/\.[a-z]{2,4}$/i))) { 
     url = url.replace(new RegExp(/\.[a-z]{2,4}$/i),""); 
    } 

    // CHECK TO SEE IF THERE IS A DOT '.' LEFT IN THE STRING 
    var subDomain = (url.match(new RegExp(/\./g))) ? true : false; 
    return(subDomain); 
} 

结果：

 
mydomain.com -> false 

subdomain.mydomain.com -> true 

mydomain.com. -> true 

Answer 1

实际上，你可以在一个正则表达式，例如测试：

var isSubdomain = function(url) { 
 
    url = url || 'http://www.test-domain.com'; // just for the example 
 
    var regex = new RegExp(/^([a-z]+\:\/{2})?([\w-]+\.[\w-]+\.\w+)$/); 
 

 
    return !!url.match(regex); // make sure it returns boolean 
 
} 
 

 
console.log(isSubdomain("example.com")); 
 
console.log(isSubdomain("http://example.com:4000")); 
 
console.log(isSubdomain("www.example.com:4000")); 
 
console.log(isSubdomain("https://www.example.com")); 
 
console.log(isSubdomain("sub.example.com")); 
 
console.log(isSubdomain("example.co.uk")); //it doesn't work on these very specific cases