I have a regex for youtube links that I am using in a webapp. The issue is that one of the things I didnt realize when doing this editor thing is that people could make an a with an href to youtube.
I am replacing the youtube links for a custom component. The thing is that I dont want to substitue the links that are between "
Here is my regex:
youtubeRegex = /(?:https?:)?(?:\/\/)?(?:www\.)?(?:youtu\.be\/|youtube(?:\-nocookie)?\.(?:[A-Za-z]{2,4}|[A-Za-z]{2,3}\.[A-Za-z]{2})\/)(?:watch|embed\/|vi?\/)*(?:\?[\w=&]*vi?=)?([^#&\?\/]{11}).*?/g;
Right now the regex gets all this examples:
https://www.youtube.com/watch?v=njpgevZ_MUc
"https://www.youtube.com/watch?v=njpgevZ_MUc
https://www.youtube.com/watch?v=njpgevZ_MUc"
"https://www.youtube.com/watch?v=njpgevZ_MUc" (this one should not be matched but it gets matched)
How do I edit my regex so it doesnt match the last one but still matches the rest?
Related
I'm writing a simple bot that broadcasts messages to clients based on messages from a server. This will be done in JavaScript but I am trying to understand Regex. I've been Googling for the past hour and I've come so close but I am simply unable to solve this one.
Basically I need to retrieve everything between the second / and the first [. It sounds really simple but I cannot figure out how to do this.
Here's some sample code:
192.168.1.1:33291/76561198014386231/testName joined [linux/76561198014386231]
Here's the Regex I've come up with:
\/(.*?)\[
I've found lots of similar questions here on StackOverflow but most of them seem specific to a particular language or end up being too complex and I'm unable to whittle down the query.
I know this is a simple one, but I am totally stumped.
Instead of .*?. Then you could match everything but a forward slash by doing [^\/]*.
([^\/]*)\s*\[
Live preview
If it needs to be after the second slash. As in the contents between the second slash and the square bracket can contain slashes. Then you could do:
(?:.*?\/){2}(.*)\s*\[
Live preview
Remove the \s* if you want to. I'm just assuming you don't care about that whitespace.
I am trying to figure out how to look through a string and replace any word which ends at ".com" at the end with a valid url link.
for example:
"google.com has launces a .." will be replaced with
"<.a href='google.com'>google.com <./a> has launches .."
// I tried following code, but it only works for finding word which starts with "www."
data.rows[j].content = data.rows[j].content.replace(
/(^|<|\s)(www\..+?\..+?)(\s|>|$)/g,'$2'
)
First, I recommend learning how regex works. It's a very powerful tool that all developers should understand because it appears in many different programming languages.
Once you understand the basics, this should make more sense:
/(^|<|\b)(\S+?\.com)(\b|>|$)/g
Regex101 Demo - (for a breakdown of the regex, look in the top-right pane)
https://regex101.com/r/oF0mA9/2 should do the trick from the regex front.
You can follow this ways for ending com
(http(s?):)|([/|.|\w|\s])*\.(?:com)
OR
(?i)\.(com)$
OR
(?:([^:/?#]+):)?(?://([^/?#]*))?([^?#]*\.(?:com))(?:\?([^#]*))?(?:#(.*))?
Resource Link:
Regex to check if valid URL that ends in .jpg, .png, or .gif
Currently on my GA Account I have the following URL's from our website tracked:
domain/contact-us/
domain/contact-us/global-contact-list.aspx
domain/contact-us/contactlist.aspx
The first two are from our new website which we want to track, the last one is from our old website (traffic is still being tracked but we do not want to use this)
I tried using a regex filter on this as the following:
(^/contact-us/global-contact-list\.aspx)|(^/contact-us/)
Reading up, I believe this looks for matches of exactly:
/contact-us/global-contact-list or /contact us/ but would disallow /contact-us/contactlist/
for some reason, the above one is still coming through. Can someone please see as to why this may be happening or know why this is happening?
You need to add a negative look-behind or a end of string anchor:
(^/contact-us/global-contact-list\.aspx)|(^/contact-us/$)
or
(^/contact-us/global-contact-list\.aspx)|(^/contact-us/(?!contactlist/))
This way, you will exclude /contact-us/contactlist/ from matching.
Have a look at the Demo 1 and Demo 2.
BTW, /contact us/ will not pass since (^/contact-us/) only allows a hyphen. You should add a space, e.g. (^/contact-us/global-contact-list\.aspx)|(^/contact[-\s]us/$).
Also, (^/contact-us/global-contact-list\.aspx) won't match /contact-us/global-contact-list because it needs to match .aspx.
I am currently learning regex and I am trying to filter all links (eg: http://www.link.com/folder/file.html) from a document with notepad++. Actually I want to delete everything else so that in the end only the http links are listed.
So far I tried this : http\:\/\/www\.[a-zA-Z0-9\.\/\-]+
This gives me all links which is find, but how do I delete the remaining stuff so that in the end I have a neat list of all links?
If I try to replace it with nothing followed by \1, obviously the link will be deleted, but I want the exact opposite to have everything else deleted.
So it should be something like:
- find a string of numbers, letters and special signs until "http"
- delete what you found
- and keep searching for more numbers, letters ans special signs after "html"
- and delete that again
Any ideas? Thanks so much.
In Notepad++, in the Replace menu (CTRL+H) you can do the following:
Find: .*?(http\:\/\/www\.[a-zA-Z0-9\.\/\-]+)
Replace: $1\n
Options: check the Regular expression and the . matches newline
This will return you with a list of all your links. There are two issues though:
The regex you provided for matching URLs is far from being generic enough to match any URL. If it is working in your case, that's fine, else check this question.
It will leave the text after the last matched URL intact. You have to delete it manually.
The answer made previously by #psxls was a great help for me when I have wanted to perform a similar process.
However, this regex rule was written six years ago now: accordingly, I had to adjust / complete / update it in order it can properly work with the some recent links, because:
a lot of URL are now using HTTPS instead of HTTP protocol
many websites less use www as main subdomain
some links adds punctuation mark (which have to be preserved)
I finally reshuffle the search rule to .*?(https?\:\/\/[a-zA-Z0-9[:punct:]]+) and it worked correctly with the file I had.
Unfortunately, this seemingly simple task is going to be almost impossible to do in notepad++. The regex you would have to construct would be...horrible. It might not even be possible, but if it is, it's not worth it. I pretty much guarantee that.
However, all is not lost. There are other tools more suitable to this problem.
Really what you want is a tool that can search through an input file and print out a list of regex matches. The UNIX utility "grep" will do just that. Don't be scared off because it's a UNIX utility: you can get it for Windows:
http://gnuwin32.sourceforge.net/packages/grep.htm
The grep command line you'll want to use is this:
grep -o 'http:\/\/www.[a-zA-Z0-9./-]\+\?' <filename(s)>
(Where <filename(s)> are the name(s) of the files you want to search for URLs in.)
You might want to shake up your regex a little bit, too. The problems I see with that regex are that it doesn't handle URLs without the 'www' subdomain, and it won't handle secure links (which start with https). Maybe that's what you want, but if not, I would modify it thusly:
grep -o 'https\?:\/\/[a-zA-Z0-9./-]\+\?' <filename(s)>
Here are some things to note about these expressions:
Inside a character group, there's no need to quote metacharacters except for [ and (sometimes) -. I say sometimes because if you put the dash at the end, as I have above, it's no longer interpreted as a range operator.
The grep utility's syntax, annoyingly, is different than most regex implementations in that most of the metacharacters we're familiar with (?, +, etc.) must be escaped to be used, not the other way around. Which is why you see backslashes before the ? and + characters above.
Lastly, the repetition metacharacter in this expression (+) is greedy by default, which could cause problems. I made it lazy by appending a ? to it. The way you have your URL match formulated, it probably wouldn't have caused problems, but if you change your match to, say [^ ] instead of [a-zA-Z0-9./-], you would see URLs on the same line getting combined together.
I did this a different way.
Find everything up to the first/next (https or http) (then everything that comes next) up to (html or htm), then output just the '(https or http)(everything next) then (html or htm)' with a line feed/ carriage return after each.
So:
Find: .*?(https:|http:)(.*?)(html|htm)
Replace with: \1\2\3\r\n
Saves looking for all possible (incl non-generic) url matches.
You will need to manually remove any text after the last matched URL.
Can also be used to create url links:
Find: .*?(https:|http:)(.*?)(html|htm)
Replace: \1\2\3\r\n
or image links (jpg/jpeg/gif):
Find: .*?(https:|http:)(.*?)(jpeg|jpg|gif)
Replace: <img src="\1\2\3">\r\n
I know my answer won't be RegEx related, but here is another efficient way to get lines containing URLs.
This won't remove text around links like Toto mentioned in comments.
At least if there is nice pattern to all links, like https://.
CTRL+F => change tab to Mark
Insert https://
Tick Mark to bookmark.
Mark All.
Find => Bookmarks => Delete all lines without bookmark.
I hope someone who lands here in search of same problem will find my way more user-friendly.
You can still use RegEx to mark lines :)
I'm very very new to regex. I'd managed to not touch it with a 10-foot pole for so long. And I tried my best to avoid it so far. But now a personal project is pushing me to learn it.
So I started. And I'm going through the tutorial located here:http://www.regular-expressions.info/tutorial.html
Currently I'm here: http://www.regular-expressions.info/repeat.html
My question is:
The tutorial says <[A-Za-z][A-Za-z0-9]*> will match an HTML tag.
But wouldn't it also match invalid html tags like - <h11> or <h111>?
Also how would it match the closing tags?
Edit - My question is very specific. I am referring to one particular example in one particular tutorial to clarify whether or not my understanding of repetitions is correct. Again, I REPEAT, I DO NOT care about html parsing with regex.
I don't see any harm in answering your question seeing as how you are attempting to learn regex:
1) Yes, it will match invalid tags as well because it's any letter followed by any zero or more matches of another letter or a number.
2) It will not match closing tags (there would have to be a search for a / somewhere in there).
One more comment: one way people used to use to look for html tags inside a document was to look for the pattern of opening and closing brackets, like so:
<\/?[^>]*>
That's opening-bracket, an optional slash, (anything but a closing bracket)-repeated and then a closing bracket. Of course, I am not recommending anyone do this. It's merely left here as an exercise.
The tutorial says <[A-Za-z][A-Za-z0-9]*> will match an HTML tag.
But wouldn't it also match invalid html tags like - or ?
Also how would it match the closing tags?
Yes, that will match <h11> as well as <X098wdfhfdshs98fhj2hsdljhkvjnvo9sudvsodfih23234osdfs>.
If you want to just match a letter followed by an optional single digit, so you'd match <h1>, then you want <[A-Za-z][0-9]?>