I have an Asp.Net website on which I'm implementing some basic anti-spam stuff via the validation controls.
One such regex is: "^(?!.*(//|[.]({com|net|info|uk|etc}))).*$"
It pretty much does what it needs to as far as blocking goes — it doesn't need to be too sophisticated. However, I want to include the option to whitelist my own domain.
So, I want to block all .uk domains, except mydomain.co.uk.
This is a regex step beyond me — can anyone help?
You may use a nested negative lookbehind while uk to fail the already existing negative lookahead for mydomain.co. part before matching uk:
^(?!.*(//|[.](com|net|info|(?<!mydomain\.co\.)uk))).*$
RegEx Demo
Take note of (?<!mydomain\.co\.) which is a negative lookbehind to not to match uk if it is preceded by mydomain.co..
Related
Let's say my domains are:
www.test.com
www.test.com/en-gb
www.test.com/cn-cn
These are language sites, the first is the main US English site. In Google Analytics I want to set up a filter to only show me traffic of the first (US) domain. I could do this, I think:
^\/(en-gb|cn-cn).*$
If I EXCLUDE my Request URI with that filter pattern, then I should get a view for the en-US domain. However, I'm interested in understanding regex better so here is some test data and code which I am trying out on http://www.regextester.com/
Regular expression:
^\/(en-gb|cn-cn).*$
Test String
/cn-cn/about
/cn-cn/about/
/cn-cn
/cn-cn/about/test
/en-gb/
/en-gb
/en-gb-test/
/en-gb/aboutus/
/en-gb?q=1
/en-gb/?q=1
/about-us
/test?q=1
/aword/me/
/three
/about/en-gb/
/about/en-gb-test/
/test-yes/
/test/me/
/hello/world/
My questions:
If you try this out, you'll notice that /en-gb-test/ is actually matched with the Regex. How do I avoid this?
Also, let's say I wanted to have a rule to NEGATE this whole option. So rather than telling Google Analytics to "exclude", I am curious how I could write the opposite of this same rule. So basically, catch all URLs that are not in /en-gb and /cn-cn sub-folders.
Thanks in advance!
You may stop the regex from matching en-gb-test by making sure you may / or ? after it or the end of the string
^\/(en-gb|cn-cn)([\/?]|$)
See the regex demo. If you really need to get the rest of the string, add .* after [\/?]: ^\/(en-gb|cn-cn)([\/?]|$).
Details:
^ - start of string
\/ - a / (note that you do not need to escape / in GA regex)
(en-gb|cn-cn) - a capturing group with 2 alternatives, either en-gb or cn-cn
([\/?]|$) - a capturing group with two alternatives: a ? or / OR the end of the string.
In RE2 regex, you cannot use lookaheads that are crucial when you need to match something other than something else. It would look like ^(?!\/(en-gb|cn-cn)([\/?]|$)).*, but it is not possible with RE2.
I'm new to regex. I need to find instances of example.com in an .SQL file in Notepad++ without those instances being part of subdomain.example.com(edited)
From this answer, I've tried using ^((?!subdomain))\.example\.com$, but this does not work.
I tested this in Notepad++ and # https://regex101.com/r/kS1nQ4/1 but it doesn't work.
Help appreciated.
Simple
^example\.com$
with g,m,i switches will work for you.
https://regex101.com/r/sJ5fE9/1
If the matching should be done somewhere in the middle of the string you can use negative look behind to check that there is no dot before:
(?<!\.)example\.com
https://regex101.com/r/sJ5fE9/2
Without access to example text, it's a bit hard to guess what you really need, but the regular expression
(^|\s)example\.com\>
will find example.com where it is preceded by nothing or by whitespace, and followed by a word boundary. (You could still get a false match on example.com.pk because the period is a word boundary. Provide better examples in your question if you want better answers.)
If you specifically want to use a lookaround, the neative lookahead you used (as the name implies) specifies what the regex should not match at this point. So (?!subdomain\.)example trivially matches always, because example is not subdomain. -- the negative lookahead can't not be true.
You might be better served by a lookbehind:
(?<!subdomain\.)example\.com
Demo: https://regex101.com/r/kS1nQ4/3
Here's a solution that takes into account the protocols/prefixes,
/^(www\.)?(http:\/\/www\.)?(https:\/\/www\.)?example\.com$/
I'm setting up URL Rewrite on an IIS and i need to match the following URLs using regex.
http://sub.mysite.com
sub.mysite.com
sub.mysite.com/
sub.mysite.com/Site1
sub.mysite.com/Site1/admin
but not:
sub.mysite.com/admin
sub.mysite.com/admin/somethingelse
sub.mysite.com/admin/admin
The site it self (sub.mysite.com) should not be "hardcoded" in the expression. Instead, it should be matched by something like .*.
I'm really blank on this one. I did find solutions to match the different URLs but once i try to combine them either none of them match or all of them do.
I hope someone can help me.
For your specific case, assuming you are matching the part after the domain (REQUEST_URI):
(?!/admin).*
(?!...) is a negative lookahead. I am not sure if it is supported in the IIS URL Rewrite engine. If not, a better approach would be to check for a complementary approach:
Or as #kirilloid said, just match /admin/? and discard (pay attention to slashes).
BTW. if you want to quickly test RegExps with a "visual" feedback, I highly recommend http://gskinner.com/RegExr/
([A-Za-z0-9]+.)+.com(?!/admin)/?([A-Za-z0-9]+/?)*
this should do the trick
Sorry for the dummy question but I'm a regular expressions newbie.
I want these matches:
MATCH! http://www.google.com/search?q=...
NO MATCH http://www.googledummy.com/search?q=...
MATCH! http://www.google.it/search?q=...
NO MATCH! http://www.google.it/
NO MATCH! http://www.google.it/foobar
MATCH! google.it/search?q=...
MATCH! google.xxxxx/search?q=...
Should my regex be something like this?
google.[*$]/search
You probably want something like this:
^(?:https?://)?(?:[^.\s]+\.)*google(\.\w+){1,2}/search\?q=
This regex allows:
^ - match from the start - do not allow partial matching of the domain.
(?:https?://)? - http or https protocol.
(?:[^.]+\.)* - sub domains, but not other characters: hello.google.com is OK.
google
Does not allow:
http://notgoogle.com/search?q=
http://example.com?google.com/search?q=
Problems:
(\.\w+){1,2} - allows google.co.il, but also google.hackers.com. It's problematic unless you want to white list all two-word tlds.
the q query parameter may not be the first one (though, maybe that is one of the requirements).
\w may not fit all characters that are valid in top level domains (though google is not likely to buy google.קום)
Example: http://rubular.com/r/Avd5RFs3oH
Conclusion - If at all applicable, use a URL parser :)
from what you wrote I would say
google\.[a-z]+\/search
whether you should use \/ or just / before search depends on the language you are using.
As SeRPRo this does not work for google.co.uk, to make it working with it you can use:
google\.[a-z]+(?:\.[a-z])?\/search
(is there any country that requires a third level?)
This one works:
google\.[a-zA-Z\.]+/(search\W.+)
Example
You might want the following:
google\.[a-zA-Z.]+/search
Both other answers should work fine until you meet a second-level google site like google.com.ua
I have a regex pattern for URL's that I use to check for links in a body of text. The only problem is that the pattern will match this link
stackoverflow.com
And this sentence
I'm a sentence.Next Sentence.
Obviously this would make sense because my pattern doesn't strong check .com, .co.uk, .com.au etc
I want it to match stackoverflow.com and not the latter.
As I'm no Regex expert, does anyone know of any good Regex patterns for checking for all types of URL's in a body text, while not matching the sentences like above?
If I have to strong check the domain extension, I suppose I'll have to settle.
Here's my pattern, but i don't think it help.
(([\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})*)?
I would definitely suggest finding a working regex that someone else has made (which would probably include a strong check on the domain extension), but here is one possible way to just modify your existing regex.
It requires that you make the assumption that usually links will not mix case in the domain extension, for example you might see .COM or .com but probably not .Com, if you only match domain extensions that don't mix case then you would avoid matching most sentences.
In the middle of your regex you have [\w]{2,4}, try changing this to ([A-Z]{2,4}|[a-z]{2,4}) (or (?:[A-Z]{2,4}|[a-z]{2,4}) if you don't want a new captured group).