How to validate my URL efficienty using JavaScript? - javascript

My regex successfully validates many URLs except http://www.google
Here's my URL validator in JSFiddle: http://jsfiddle.net/z23nZ/2/
It correctly validates the following URLs:
http://www.google.com gives True
www.google.com gives True
http://www.rootsweb.ancestry.com/~mopoc/links.htm gives True
http:// www. gives False
...but not this one:
http://www.google gives True
It's not correct to return true in this case. How can I validate that case?

I think you need to way simplify this. There are plenty of URL validation RegExes out there, but as an exercise, I'll go through my thought process for constructing one.
First, you need to match a protocol if there is one: /((http|ftp)s?:\/\/)?
Then match any series of non-whitespace characters: \S+
If you're trying to pick out URLs from text, you'll want to look for signs that it is a URL. Look for dots or slashes, then more non-whitespace: [\.\/]\S*/
Now put it all together:
/(((http|ftp)s?:\/\/)|(\S+[\.\/]))\S*[^\s\.]*/
I'm guessing that your attempting to look for www.google is because of the new TLDs... the fact is, such URLs might just look like google, and so any word could be a URL. Trying to come up with a catch-all regex which matches valid URLs and nothing else isn't possible, so you're best just going with something simple like the above.
Edit: I've stuck a | in there between the protocol part and the non-whitespace-then-dot-or-slash part to match http://google if people choose to write new URLs like that
Edit 2: See comments for the next improvement. It makes sure google.com matches, http://google matches, and even google/ matches, but not a..

Related

JS regex to get domain name from an email [duplicate]

How can I extract only top-level and second-level domain from a URL using regex? I want to skip all lower level domains. Any ideas?
Here's my idea,
Match anything that isn't a dot, three times, from the end of the line using the $ anchor.
The last match from the end of the string should be optional to allow for .com.au or .co.nz type of domains.
Both the last and second last matches will only match 2-3 characters, so that it doesn't confuse it with a second-level domain name.
Regex:
[^.]*\.[^.]{2,3}(?:\.[^.]{2,3})?$
Demonstration:
Regex101 Example
Updated 2019
This is an old question, and the challenge here is a lot more complicated as we start adding new vanity TLDs and more ccTLD second level domains (e.g. .co.uk, .org.uk). So much so, that a regular expression is almost guaranteed to return false positives or negatives.
The only way to reliably get the primary host is to call out to a service that knows about them, like the Public Suffix List.
There are several open-source libraries out there that you can use, like psl, or you can write your own.
Usage for psl is quite intuitive. From their docs:
var psl = require('psl');
// Parse domain without subdomain
var parsed = psl.parse('google.com');
console.log(parsed.tld); // 'com'
console.log(parsed.sld); // 'google'
console.log(parsed.domain); // 'google.com'
console.log(parsed.subdomain); // null
// Parse domain with subdomain
var parsed = psl.parse('www.google.com');
console.log(parsed.tld); // 'com'
console.log(parsed.sld); // 'google'
console.log(parsed.domain); // 'google.com'
console.log(parsed.subdomain); // 'www'
// Parse domain with nested subdomains
var parsed = psl.parse('a.b.c.d.foo.com');
console.log(parsed.tld); // 'com'
console.log(parsed.sld); // 'foo'
console.log(parsed.domain); // 'foo.com'
console.log(parsed.subdomain); // 'a.b.c.d'
Old answer
You could use this:
(\w+\.\w+)$
Without more details (a sample file, the language you're using), it's hard to discern exactly whether this will work.
Example: http://regex101.com/r/wD8eP2
Also, you can likely do that with some expression similar to,
^(?:https?:\/\/)(?:w{3}\.)?.*?([^.\r\n\/]+\.)([^.\r\n\/]+\.[^.\r\n\/]{2,6}(?:\.[^.\r\n\/]{2,6})?).*$
and add as much as capturing groups that you want to capture the components of a URL.
Demo
If you wish to simplify/modify/explore the expression, it's been explained on the top right panel of regex101.com. If you'd like, you can also watch in this link, how it would match against some sample inputs.
RegEx Circuit
jex.im visualizes regular expressions:
For anyone using JavaScript and wanting a simple way to extract the top and second level domains, I ended up doing this:
'example.aus.com'.match(/\.\w{2,3}\b/g).join('')
This matches anything with a period followed by two or three characters and then a word boundary.
Here's some example outputs:
'example.aus.com' // .aus.com
'example.austin.com' // .austin.com
'example.aus.com/howdy' // .aus.com
'example.co.uk/howdy' // .co.uk
Some people might need something a bit cleverer, but this was enough for me with my particular dataset.
Edit
I've realised there are actually quite a few second-level domains which are longer than 3 characters (and allowed). So, again for simplicity, I just removed the character counting element of my regex:
'example.aus.com'.match(/\.\w*\b/g).join('')
Since TLDs now include things with more than three-characters like .wang and .travel, here's a regex that satisfies these new TLDs:
([^.\s]+\.[^.\s]+)$
Strategy: starting at the end of the string, look for one or more characters that aren't periods or whitespace, followed by a single period, followed by one or more characters that aren't periods or whitespace.
http://regexr.com/3bmb3
With capturing groups you can achieve some magix.
For example, consider the following javascript:
let hostname = 'test.something.else.be';
let domain = hostname.replace(/^.+\.([^\.]+\.[^\.]+)$/, '$1');
document.write(domain);
This will result in a string containing 'else.com'. This is because the regex itself will match the complete string and the capturing group will be mapped to $1. So it replaces the complete string 'test.something.else.com' with '$1' which is actually 'else.com'.
The regex isn't pretty and can probably be made more dynamic with things like {3} for defining how many levels deep you want to look for subdomains, but this is just an illustration.
if you want all specific Top Level Domain name then you can write regular expression like this:
[RegularExpression("^(https?:\\/\\/)?(([\\w]+)?\\.?(\\w+\\.((za|zappos|zara|zero|zip|zippo|zm|zone|zuerich|zw))))\\/?$", ErrorMessage = "Is not a valid fully-qualified URL.")]
You can also put more domain name from this link:
https://www.icann.org/resources/pages/tlds-2012-02-25-en
The following regex matches a domain with root and tld extractions (named capture groups) from a url or domain string:
(?:\w+:\/{2})?(?<cs_domain>(?<cs_domain_sub>(?:[\w\-]+\.)*?)(?<cs_domain_root>[\w\-]+(?<cs_domain_tld>(?:\.\w{2})?(?:\.\w{2,3}|\.xn-+\w+|\.site|\.club))))\|
It's hard to say if it is perfect, but it works on all the test data sets that I have put it against including .club, .xn-1234, .co.uk, and other odd endings. And it does it in 5556 steps against 40k chars of logs, so the efficiency seems reasonable too.
If you need to be more specific:
/\.(?:nl|se|no|es|milru|fr|es|uk|ca|de|jp|au|us|ch|it|io|org|com|net|int|edu|mil|arpa)/
Based on http://www.seobythesea.com/2006/01/googles-most-popular-and-least-popular-top-level-domains/

search match beetwen three conditions [duplicate]

I am using the following regex for validating youtube video share url's.
var valid = /^(http\:\/\/)?(youtube\.com|youtu\.be)+$/;
alert(valid.test(url));
return false;
I want the regex to support the following URL formats:
http://youtu.be/cCnrX1w5luM
http://youtube/cCnrX1w5luM
www.youtube.com/cCnrX1w5luM
youtube/cCnrX1w5luM
youtu.be/cCnrX1w5luM
I tried different regex but I am not getting a suitable one for share links. Can anyone help me to solve this.
Here's a regex I use to match and capture the important bits of YouTube URLs with video codes:
^((?:https?:)?\/\/)?((?:www|m)\.)?((?:youtube(-nocookie)?\.com|youtu.be))(\/(?:[\w\-]+\?v=|embed\/|v\/)?)([\w\-]+)(\S+)?$
Works with the following URLs:
https://www.youtube.com/watch?v=DFYRQ_zQ-gk&feature=featured
https://www.youtube.com/watch?v=DFYRQ_zQ-gk
http://www.youtube.com/watch?v=DFYRQ_zQ-gk
//www.youtube.com/watch?v=DFYRQ_zQ-gk
www.youtube.com/watch?v=DFYRQ_zQ-gk
https://youtube.com/watch?v=DFYRQ_zQ-gk
http://youtube.com/watch?v=DFYRQ_zQ-gk
//youtube.com/watch?v=DFYRQ_zQ-gk
youtube.com/watch?v=DFYRQ_zQ-gk
https://m.youtube.com/watch?v=DFYRQ_zQ-gk
http://m.youtube.com/watch?v=DFYRQ_zQ-gk
//m.youtube.com/watch?v=DFYRQ_zQ-gk
m.youtube.com/watch?v=DFYRQ_zQ-gk
https://www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
http://www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
//www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
https://www.youtube.com/embed/DFYRQ_zQ-gk?autoplay=1
https://www.youtube.com/embed/DFYRQ_zQ-gk
http://www.youtube.com/embed/DFYRQ_zQ-gk
//www.youtube.com/embed/DFYRQ_zQ-gk
www.youtube.com/embed/DFYRQ_zQ-gk
https://youtube.com/embed/DFYRQ_zQ-gk
http://youtube.com/embed/DFYRQ_zQ-gk
//youtube.com/embed/DFYRQ_zQ-gk
youtube.com/embed/DFYRQ_zQ-gk
https://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk?autoplay=1
https://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
http://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
//www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
https://youtube-nocookie.com/embed/DFYRQ_zQ-gk
http://youtube-nocookie.com/embed/DFYRQ_zQ-gk
//youtube-nocookie.com/embed/DFYRQ_zQ-gk
youtube-nocookie.com/embed/DFYRQ_zQ-gk
https://youtu.be/DFYRQ_zQ-gk?t=120
https://youtu.be/DFYRQ_zQ-gk
http://youtu.be/DFYRQ_zQ-gk
//youtu.be/DFYRQ_zQ-gk
youtu.be/DFYRQ_zQ-gk
https://www.youtube.com/HamdiKickProduction?v=DFYRQ_zQ-gk
The captured groups are:
protocol
subdomain
domain
path
video code
query string
https://regex101.com/r/vHEc61/1
You're missing www in your regex
The second \. should optional if you want to match both youtu.be and youtube (but I didn't change this since just youtube isn't actually a valid domain - see note below)
+ in your regex allows for one or more of (youtube\.com|youtu\.be), not one or more wild-cards.
You need to use a . to indicate a wild-card, and + to indicate you want one or more of them.
Try:
^(https?\:\/\/)?(www\.youtube\.com|youtu\.be)\/.+$
Live demo.
If you want it to match URLs with or without the www., just make it optional:
^(https?\:\/\/)?((www\.)?youtube\.com|youtu\.be)\/.+$
Live demo.
Invalid alternatives:
If you want www.youtu.be/... to also match (at the time of writing, this doesn't appear to be a valid URL format), put the optional www. outside the brackets:
^(https?\:\/\/)?(www\.)?(youtube\.com|youtu\.be)\/.+$
youtube/cCnrX1w5luM (with or without http://) isn't a valid URL, but the question explicitly mentions that the regex should support that. To include this, replace youtu\.be with youtu\.?be in any regex above. Live demo.
I know I'm like 2 years late to the party, but I was needing to write something up anyway, and seems to fit every test case that I can throw at it. Should be able to reference the first match ($1) to get the ID. Matches the http, https, www and non-www, youtube.com, youtu.be, /watch? and /watch.php? on youtube.com (youtu.be does not use these), and it supports matching even when there are other variables in the URL string (?t= for time, ?list= for playlists, etc).
(?:https?:\/\/)?(?:youtu\.be\/|(?:www\.|m\.)?youtube\.com\/(?:watch|v|embed)(?:\.php)?(?:\?.*v=|\/))([a-zA-Z0-9\_-]+)
Format for YouTube videos has changed. This regex works for all cases:
^(http(s)??\:\/\/)?(www\.)?((youtube\.com\/watch\?v=)|(youtu.be\/))([a-zA-Z0-9\-_])+
Tests here.
Based on so many other regex; this is the best I have got:
((http(s)?:\/\/)?)(www\.)?((youtube\.com\/)|(youtu.be\/))[\S]+
Test:
http://regexr.com/3bga2
Try this:
((http://)?)(www\.)?((youtube\.com/)|(youtu\.be)|(youtube)).+
http://regexr.com?36o7a
I took one of the answers from here and added support for a few edge cases that I noticed in my dataset. This should work for pretty much any valid url.
^(?:https?:)?(?:\/\/)?(?:youtu\.be\/|(?:www\.|m\.)?youtube\.com\/(?:watch|v|embed)(?:\.php)?(?:\?.*v=|\/))([a-zA-Z0-9\_-]{7,15})(?:[\?&][a-zA-Z0-9\_-]+=[a-zA-Z0-9\_-]+)*(?:[&\/\#].*)?$
I tried this one and it works fine for me.
(?:http(?:s)?:\/\/)?(?:www\.)?(?:youtu\.be\/|youtube\.com\/(?:(?:watch)?\?(?:.*&)?v(?:i)?=|(?:embed|v|vi|user)\/))([^\?&\"'<> #]+)
You can check here https://regex101.com/r/Kvk0nB/1
https://regexr.com/62kgd
^((http|https)\:\/\/)?(www\.youtube\.com|youtu\.?be)\/((watch\?v=)?([a-zA-Z0-9]{11}))(&.*)*$
https://www.youtube.com/watch?v=YPz9zqakRbk
https://www.youtube.com/watch?v=YPz9zqakRbk&t=11
http://youtu.be/cCnrX1w5luM&y=12
http://youtu.be/cCnrX1w5luM
http://youtube/cCnrXswsluM
www.youtube.com/cCnrX1w5luM
youtube/cCnrX1w5luM
Check this pattern instead:
r'(?i)(http.//|https.//)*[A-Za-z0-9._%+-]+\.\w+'

JS Regex: Parse urls with conditions

I had a requirement of parsing a set of urls and extract specific elements from urls under special conditions. To explain it further, consider a set of urls:
http://www.example.com/appName1/some/extra/parts/keyword/rest/of/the/url
http://www.somewebsite.com/appName2/some/extra/parts/keyword/rest/of/the/url
http://www.someothersite.com/appname3/rest/of/the/url
As you can see, there are two sets of urls, one having the word "keyword" in it and others which don't. In my code, I will receive the part of the url after domain name (eg: /appName1/some/extra/parts/keyword/rest/of/the/url).
I have two tasks, one check if the word "keyword" is present in the url, and second, to be done only if "keyword" is not present in url, parse the url to fetch the two groups as the appName and rest of the url (eg: grp 1. appName3 and grp 2. rest/of/the/url for url 3, as it doesn't have "keyword" in it). The whole thing should be done in one regex.
My progress:
I was able to parse the app name and rest of the url into groups, but was not able to apply the condition.
I found out a way to select stings not having "keyword" in it, I'm not sure if it's the right way to do it:^((?!.\*keyword).\*)$
Next, to combine the above two, I tried something I found after a long search, which has syntax (?(?=regex)then|else) Reference. And the result was :
(?(?=^((?!.*keyword).*)$)\1)But it says invalid group structure.
I had gone through many stackoverflow entries and tutorials, but couldn't reach the actual requirement. Please help me solve this.
Yes, this is in fact possible. As far as I understand, you have the following cases:
/appName/some/extra/parts/keyword/rest/of/the/url
/appName/rest/of/the/url
You want your regex to not match the first one at all, while in the second case you want "appName" in one group and "rest/of/the/url" in another. The following regex will do that:
^(?!.*\/keyword\/)\/(.*?)\/(.*)$
Explanation:
^ assert position at the start of the string`
(?!.*\/keyword\/) is a negative lookahead, and looks ahead to make sure the string does not contain /keyword/. This is where the magic happens
\/ matches "/", i.e. the slash right after the domain name
(.*?)\/ captures the first group (appname in your example) greedily until next slash
(.*)$ is the group that captures "rest/of/the/url"

Javascript Regex patterns to pickup URLs

To start off I know this is bad practice. I know there are libraries out there that are supposed to help with this; however, this is the task to which I was assigned and changing this whole thing to work with a library will be much more work than we can take on right now (since we are on a tight time frame).
In our web app we have fields that people usually type URLs into. We have been assigned a task to 'linkify' anything that looks like a URL. Currently the people who wrote our app seemed to have used a regex to determine if a string of text is a URL. I am basing my regex off that (I am no regex guru, not even a novice).
The 'search' regex looks like so
function DoesTextContainLinks(linktText) {
//replace all urls with links!
var linkifyValue = /((ftp|https?):\/\/)?(www\.)?([a-zA-Z0-9\-]{1,}\.){1,}[a-zA-Z0-9]{1,4}(:[0-9]{1,5})?(\/[a-zA-Z0-9\-\_\.\?\&\#]{1,})*(\/)?$/.test(linktText);
return linkifyValue;
}
Using this regex and https://regex101.com/ I have come up with two regexes that work most of the time.
function WrapLinkTextInAnchorTag(linkText) {
//capture links that only have www and add http to the begining of them (regex ignores entries that have http, https, and ftp in them. They are handled by the next regexes)
linkText = linkText.replace(/(^(?:(?!http).)*^(?:(?!ftp).)(www\.)?([a-zA-Z0-9\-]{1,}\.){1,}[a-zA-Z0-9]{1,4}(:[0-9]{1,5})?(\/[a-zA-Z0-9\-\_\.\?\&\#]{1,})*(\/)?$)/gim, "<a href='http://$1'>$1</a>");
//capture links that have https and http on them and fix those too. No need to prepend http here
linkText = linkText.replace(/(((https|http|ftp?):\/\/)?(www\.)?([a-zA-Z0-9\-]{1,}\.){1,}[a-zA-Z0-9]{1,4}(:[0-9]{1,5})?(\/[a-zA-Z0-9\-\_\.\?\&\#]{1,})*(\/)?$)/gim, "<a href='$1'>$1</a>");
return linkText;
}
The problem here is that some complex URLs seem to not work. I can't understand exactly why they don't work. regex101 is pretty bad ass in that it tells you what each part is doing; however, my trouble is combining these keywords in the regex to get them to do what I want. I have two scenarios to account for : when a user types www.something.com | ftp.something.com and when a user actually types http://www.something.com.
I am looking for some help in pointing out exactly what is wrong with my 2 regexes that prevents them from capturing complicated URLs like the one below
https://pw.something.com/AAPS/default.aspx?guid=a5741c35-6fe1-31a1-b555-4028e931642b
I use this one ...
^(http|https|ftp)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(:[a-zA-Z0-9]*)?\/?([a-zA-Z0-9\-\._\?\,\'\/\\\+&%\$#\=~])*$
Look here ... Regex Tester
URL RegExp that requires (http, https, ftp)://, A nice domain, and a decent file/folder string. Allows : after domain name, and these characters in the file/folder string (letter, numbers, - . _ ? , ' / \ + & % $ # = ~). It blocks all other special characters and id good for protecting against user input!
If you look closely you will notice that nowhere in your regexps do you match an = character. That's what's breaking on the example you give.
Changing the second regexp by adding a \= to the characters supported in the path:
linkText.replace(/(((https|http|ftp?):\/\/)?(www\.)?([a-zA-Z0-9\-]{1,}\.){1,}[a-zA-Z0-9]{1,4}(:[0-9]{1,5})?(\/[a-zA-Z0-9\-\_\.\?\&\#\=]{1,})*(\/)?$)/gim, "<a href='$1'>$1</a>");
Causes your example URL to match. That said it may be worth slogging through the RFC on urls (http://www.ietf.org/rfc/rfc3986.txt) to find other characters that might be allowed in URLs (even if they have special meanings) because you're probably missing some others.

Regular expression for detecting hyperlinks

I've got this regex pattern from WMD showdown.js file.
/<((https?|ftp|dict):[^'">\s]+)>/gi
and the code is:
text = text.replace(/<((https?|ftp|dict):[^'">\s]+)>/gi,"$1");
But when I set text to http://www.google.com, it does not anchor it, it returns the original text value as is (http://www.google.com).
P.S: I've tested it with RegexPal and it does not match.
Your code is searching for a url wrapped in <> like: <http://www.google.com>: RegexPal.
Just change it to /((https?|ftp|dict):[^'">\s]+)/gi if you don't want it to search for the <>: RegexPal
As long as you know your url's start with http:// or https:// or whatever you can use:
/((https?|s?ftp|dict|www)(://)?)[A-Za-z0-9.\-]+)/gi
The expression will match till it encounters a character not allowed in the URL i.e. is not A-Za-z\.\-. It will not however detect anything of the form google.com or anything that comes after the domain name like parameters or sub directory paths etc. If that is your requirement that you can simply choose to terminate the terminating condition as you have above in your regex.
I know it seems pointless but it may be useful if you want the display name to be something abbreviated rather than the whole url in case of complex urls.
You could use:
var re = /(http|https|ftp|dict)(:\/\/\S+?)(\.?\s|\.?$)/gi;
with:
el.innerHTML = el.innerHTML.replace(re, '<a href=\'$1$2\'>$1$2<\/a>$3');
to also match URLs at the end of sentences.
But you need to be very careful with this technique, make sure the content of the element is more or less plain text and not complex markup. Regular expressions are not meant for, nor are they good at, processing or parsing HTML.

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