How can I write a opposite regex to this regex? - regex

this is a regex of a proxy, if I add this to my proxy:
(.*\.|)(abc|google)\.(org|net)
my proxy will not transmit the abc.org, abc.net, google.org, google.net's traffic.
how can I write a regex opposite to this regex? I mean only transmit the abc.org, abc.net, google.org, google.net's traffic.
EDIT-01
My thought is just want to transmit abc.org or www.abc.org, how can I do with that?

Try this:
^(?!(www\.)?(?:abc|google)\.(?:net|org)).*
Demo: https://regex101.com/r/WOnFx8/3/
I used ?! to reverse the matching of your regex. This way, it will match any domain except these specific 4 domains.
Another way to do it is by using this code to include anything before the desired domains:
^(?!(.*\.|)(?:abc|google)\.(?:net|org)).*
demo: https://regex101.com/r/WOnFx8/4/

Your regex you write
(.*\.|)(abc|google)\.(org|net)
mean any string is one of abc.org, gooogle.org, abc.net, google.net, with optional prefix string ends with dot (.)
Like: test.google.org, sub.abc.net,...
I think you want to match string like test.yahoo.com, but not test.google.org. If you can use negative look ahead, this is the answer:
^(.*\.|)(?!(abc|google)\.(org|net))\w+\.\w+$
Explain:
^ and $ to be sure your match is entire url string
Negative look ahead is to check the url is not something like abc.org, abc.net, google.org, google.net
And \w+\.\w+ to check the remain string is kind of URL type (something likes yahoo.com, etc...)

Im going to assume you have lookaheads, if so then you can simply use -
(^.*?\.(?!(abc|google))\w+\.(?:org|net)$)
Demo - https://regex101.com/r/5eC41R/3
What this does is -
Looks for the start of the url (till the first .)
Checks that next part is not abc or google
looks for the next section (till the next .)
Looks for a closing org or net
Note that since it is a lookahead it will be slow compared to other regex matches

Related

Regex for only if if a character is present then it can be succeeded

I am trying to construct a simple regex for detecting URLs. My progress is this regex:
^((https?):\/\/)?[\w.]*[\w]+\.[a-z]{3}\/?([\w\?\#.=-]+\/?)*$ But this is not actually what I want.
This can detect URLs like:
https://something.com
www.stackoverflow.com
subdomain.domain.com/something/photo.png
But this also detects
subdomain.domain.communication
My goal is this:
There must be three characters in the domain ending (.com, .org, .net). There can be a / or not after the domain ending. But if only a / is present it should look into futher regex else it shold not match. Like it should detect:
https://somewebsite.com
https://somewebsite.com/
https://somewebsite.com/webpage/some#section
But not:
https://something.commmm/
Try
^(https?:\/\/)?([\w]+\.)+[a-z]{3}(\/[\w\?\#.=-]+)*\/?$

Extracting top-level and second-level domain from a URL using regex

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/

Using reg-ex to filter URL's that contain certain words GA

I want to filter out all URL's that contain certain words, for example:
I have a URL that looks like this:
www.google.com/&SaveThis=true&SaveType=VeryFast&Page=0
And sometimes the 'Save Type' might change to slow or something. So what I want to do is show all URL's that have the 'SaveType=VeryFast' sometimes this can be in the middle of a very long URL.
I tried this:
.*SaveType=VeryFast.*
But it didn't work!
Thanks
From Tip #4 on this page, it looks like you don't need the .* on either end. That is, without the ^ and $ anchors, using SaveType=VeryFast should match any URL that contains those exact characters. It does look like word boundary anchors (\b) are not supported, so you will likely also match any URL that contains e.g. OtherSaveType=VeryFast or SaveType=VeryFastly
Otherwise, I don't see anything wrong with your expression... (?)

Regex to match anything after /

I'm basically not in the clue about regex but I need a regex statement that will recognise anything after the / in a URL.
Basically, i'm developing a site for someone and a page's URL (Local URL of Course) is say (http://)localhost/sweettemptations/available-sweets. This page is filled with custom post types (It's a WordPress site) which have the URL of (http://)localhost/sweettemptations/sweets/sweet-name.
What I want to do is redirect the URL (http://)localhost/sweettemptations/sweets back to (http://)localhost/sweettemptations/available-sweets which is easy to do, but I also need to redirect any type of sweet back to (http://)localhost/sweettemptations/available-sweets. So say I need to redirect (http://)localhost/sweettemptations/sweets/* back to (http://)localhost/sweettemptations/available-sweets.
If anyone could help by telling me how to write a proper regex statement to match everything after sweets/ in the URL, it would be hugely appreciated.
To do what you ask you need to use groups. In regular expression groups allow you to isolate parts of the whole match.
for example:
input string of: aaaaaaaabbbbcccc
regex: a*(b*)
The parenthesis mark a group in this case it will be group 1 since it is the first in the pattern.
Note: group 0 is implicit and is the complete match.
So the matches in my above case will be:
group 0: aaaaaaaabbbb
group 1: bbbb
In order to achieve what you want with the sweets pattern above, you just need to put a group around the end.
possible solution: /sweets/(.*)
the more precise you are with the pattern before the group the less likely you will have a possible false positive.
If what you really want is to match anything after the last / you can take another approach:
possible other solution: /([^/]*)
The pattern above will find a / with a string of characters that are NOT another / and keep it in group 1. Issue here is that you could match things that do not have sweets in the URL.
Note if you do not mind the / at the beginning then just remove the ( and ) and you do not have to worry about groups.
I like to use http://regexpal.com/ to test my regex.. It will mark in different colors the different matches.
Hope this helps.
I may have misunderstood you requirement in my original post.
if you just want to change any string that matches
(http://)localhost/sweettemptations/sweets/*
into the other one you provided (without adding the part match by your * at the end) I would use a regular expression to match the pattern in the URL but them just blind replace the whole string with the desired one:
(http://)localhost/sweettemptations/available-sweets
So if you want the URL:
http://localhost/sweettemptations/sweets/somethingmore.html
to turn into:
http://localhost/sweettemptations/available-sweets
and not into:
localhost/sweettemptations/available-sweets/somethingmore.html
Then the solution is simpler, no groups required :).
when doing this I would make sure you do not match the "localhost" part. Also I am assuming the (http://) really means an optional http:// in front as (http://) is not a valid protocol prefix.
so if that is what you want then this should match the pattern:
(http://)?[^/]+/sweettemptations/sweets/.*
This regular expression will match the http:// part optionally with a host (be it localhost, an IP or the host name). You could omit the .* at the end if you want.
If that pattern matches just replace the whole URL with the one you want to redirect to.
use this regular expression (?<=://).+

Exclude part of the string with regex

I'm quite bad with regex, and I'm looking to match a criteria.
This is a regex expression that should go emmbed into the url for a firewall, so It will block any url that is not like the list at the end.
This is what Im currently using but its not working:
http://www.youtube.com/(*.*)list=UUFwtOm4N5djdcuTAlNIWJaQ
This is the example url (to be blocked):
http://www.youtube.com/watch?NR=1&feature=fvwp&v=P1b5VY_Bp_o&list=UUFwtOm4N5djdcuTAlNIWJaQ
I'm trying to make a regex that will Success fully match when NR=1 or feature=fvwp
are NOT present, I asume I can do it like this: (?!^feature=fvwp$) but the v= and list=UUFwtOm4N5djdcuTAlNIWJaQ are allowed.
Also the v= should be limited to any character (uppercase and lowercase) and 11 length, I assume its: /^[a-z0-9]{11}$/
How can I build all that together and make it work so it would allow and match only on this urls excluding from allowing the previous criterias that I explained:
http://www.youtube.com/watch?v=4eK_RWpTgcc&feature=BFa&list=UUFwtOm4N5djdcuTAlNIWJaQ
http://www.youtube.com/watch?v=TLRl85TJwZM&feature=BFa&list=UUFwtOm4N5djdcuTAlNIWJaQ
http://www.youtube.com/watch?v=QEV9yqrpxkc&feature=BFa&list=UUFwtOm4N5djdcuTAlNIWJaQ
Can you block based on matching by regex? If so, just use
(.*)www\.youtube\.com/watch\?NR=1&feature=fvwp and block whatever matches that.