HTML input pattern: all except URL - html

Question

Is it real to set input pattern to all as usually, but with one exception: url are not acceptable. I mean for example all input patterns are ok, but:
ftp://example.com
http://example.com
https://example.com
we could not enter...
is it real to do without using javascript or no ?

Answer 1

With JavaScript and using the regex found here: What is the best regular expression to check if a string is a valid URL?, you could do something like this:
function isValid(inputVal){
return !/((([A-Za-z]{3,9}:(?:\/\/)?)(?:[-;:&=\+\$,\w]+#)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\+\$,\w]+#)[A-Za-z0-9.-]+)((?:\/[\+~%\/.\w-_]*)?\??(?:[-\+=&;%#.\w_]*)#?(?:[\w]*))?)/.test(inputVal);
}
isValid(document.getElementById("inputID").value);
EDIT
Without JavaScript you can do it like such
<input pattern="^(?!((([A-Za-z]{3,9}:(?:\/\/)?)(?:[-;:&=\+\$,\w]+#)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\+\$,\w]+#)[A-Za-z0-9.-]+)((?:\/[\+~%\/.\w-_]*)?\??(?:[-\+=&;%#.\w_]*)#?(?:[\w]*))?))" >
^ # start of the string
(?! # start negative look-ahead
.* # zero or more characters of any kind (except line terminators)
foobar # foobar
)

Answer 2

Choose the URL validation regex from internet ( or write your own :) ).
Put it in negative look-ahead (?!).
Add .* for match everything else.
Use your new regex in pattern attribute of the inputs.
For example if the URL validation regex is ^(((https?)|(ftp)):\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$ the inputs will be like
<input type="text" pattern="^(?!(((https?)|(ftp)):\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?).*$" />
Note: not every regex will work if you add it in negative look-ahead so just use JavaScript and inverse the result of the original regex. Also your input must be inside a form to trigger the patern validation (on form submit).

Answer 3

The question indicates you already know the regex and just want to know whether you should be using Javascript (or HTML) for this. The answer would be: probably not.
If you are filtering input for - say - a forum, using Javascript would be a bad idea because it runs locally, so the user can easily avoid the check. Use a server-sided language (most-probably PHP) to do the check.