Regex for validating domain name
Finally the underscore is invalid everywhere in all labels.
I know that this is a bit of an old post, but all of the regular expressions here are missing one very important component: the support for IDN domain names. They enable extended UTF-8 characters in domain names.
There is actually not very much to type and you will get a feel for the rhythm of test first programming.
To run the examples as is, you need an empty directory with the folders folder and make sure your web server can reach these locations.
In the near future this will be likely moved to https://github.com/regexps.
Firstly sorry for the 10,000th Reg Ex question, I realise there are other domain related questions but the regex is either not working properly, too complex, or for urls with subdomains, protocols, and filepaths.
I’ve had to retort to a very simple regex which just checks for an @ sign, something before it, at least one dot after it and at least 2 letters in the last suffix.
Is there a quick and dirty way to validate if the correct FQDN has been entered? Note that a registerable TLD can have more than one component, such as "co.uk". The rules are designed to prevent such things as mixing characters from left-to-right and right-to-left sets. regex is always going to be at best an approximation for things like this, and rules change over time.
Mine is more simple, I need to validate a domain name: So a domain in its rawest form - not even a subdomain like 4 revised: TLD should actually be labelled "subdomain" as it should include things like uk -- I would imagine the only validation possible (apart from checking against a list) would be 'after the first dot there should be one or more characters under rules #1 Thanks very much, believe me I did try! When it comes to uk, and some Japanese domains, I'm sure you will have to think twice before using regex for that.
My personal thought is that regex is not enough to validate a domain to a real-life domain.
# Literal https : # Literal : \/ # Literal / \/ # Literal / )?
) # Closes NLA [a-z0-9] # Character class (any of the characters within) [a-z0-9-] # Character class (any of the characters within) (?