REGEX: Repeating Character that is Optional - regex

I have a regex problem in which I have to capture these examples of outputs(github.com, medium.com, www.nytimes.com, www.theguardian.com, techcrunch.com) in the links, the problem is some link doesn't have "www" so I this is my regex:
https?:\/\/([w]{3}?\.?)
What I thought is that, make the www optional but I dont want to capture it. Thanks!
edit: I found the solution!
https?:\/\/([\w\-\.]+)


While your suggested solution achieves the desired effect, the suggested way would be
to use a non-capturing group
Which would turn this:
https?:\/\/([w]{3}?\.?)
Into this:
https?:\/\/(?:[w]{3}?\.?)

Related

Nino Regular Expression

I have the following text, for example:
nino&searchPhrase=jn123456&alphabetical
And I want to extract jn123456.
I've put together the following regex to extract NINOs:
(\bnino?\b.*?|Nino?\b.*?)[a-zA-Z]{2}[0-9]{6}
The problem I have is at the very end of the regex where I'm matching the last alpha character which may or may not be there.
I've tried adding the following at the end of the regex shown above without any luck:
?[a-zA-Z]{1} and
[?a-zA-Z]{1}
Could someone please look at this and let me know where I've gone wrong.
Many thanks and kind regards
Chris

You may use something like this:
^[Nn]ino&?\w*=([a-z]{2}\d{6})
which will capture "jn123456" in the first capturing group.
Demo.
If the character & can be anything else, then you may use . instead.

How to capture a group from a absolute fill path without any slash in it using JavaScript

Here is a sample file path,
/Users/X/Q/Q-doc/src/templates/demos.js
The part I would love to capture is demos.
Here is another example,
/Users/X/Q/Q-doc/src/templates/demos1.js
The target I want is demos1.
I tried to use /\/(.*).js/ to capture the filename but seems it will also capture all the things in between.

([^\/]*?)\.js$
This will grab everything that is not a forward slash, so long as it's followed by .js, from the end of the string.
See it here

Your pattern is doing what it should, however your approach needs a fix you can use this approach instead:
(\w+)\.js
Working demo
Update: in case you need a match for samples like Kyle Fairns mentioned in his comment you can use
.*\/(.*?)\.js
Working demo

regex to find domain without those instances being part of subdomain.domain

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$/

Regex for youtube URL

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+'

Regex to match surrounding text

I need to replace "something[anything]" with "somethingElse(anything)", the tricky part is anything could be anything, and I don't want to replace that. Is it possible to do with regex?
P.S. In real scenario I'd be using PHPStorm to look / replace it. It would help me a lot to show me what to put exactly at the find window.
Thank you!

Idea: Capture 'anything' in a capturing group in regex. Then, back reference it in the replacement.
For example: search for something[([^]]*)\] and replace with somethingElse($1).