I need help regarding using negative lookahead. I am using Notepad++ and I want to delete all lines except the lines that contain <title>(.*)</title>
I tried a couple of things but that didnt work.
^.*(?!<title>).*</title>
^.*(?!<title>.*</title>)
You are close:
^(?!.*<title>.*</title>).*
By this regex ^.*(?!<title>.*</title>), the regex engine will just find some position that it cannot find <title>.*</title> (end of line is one such valid position).
You need to make sure that, from the start of the line, there is no way you can find <title>.*</title> anywhere in the line. That is what my regex does.
Related
This is my sentence
「システム、スキャンモード。特定しました。
This sentence has a CRLF at the end. I wish to match the 。CRLF at the end, but ONLY if the string starts with 「.
I thought it would not be too hard to do this but I couldn't do it.
I tried multiple variations of
^(?=「).*。\R
This will go through the condition, but matches the whole line instead of just 。CRLF
I am a regex newbie, so I think this is probably not hard at all. I am just not very knowledgeable about it.
You can match 「 at the beginning of a line first and then use \K to discard the current matched text from the final match:
^「.*\K。\R
This is a follow-up question to what was solved yesterday:
Notepad++ Regex Replace Makeshift Footnotes format With Proper Markdown format
I managed to find a Regex to remove the offending semicolons in the main text area but by only cutting out the text and pasting back the result, which can only be done one by one.
I'm not sure how this can be done, but the expert can tell me.
So I have footnote references in markdown format. Two instances of the same thing:
[^1]:
[^2]:
.
.
.
[^99]:
I might not have 99 in a document but I wanted to show I need to match two digits here again.
As I said, there are two instances of these numbered references in the text. One in the main text pointing to the footnote and the footnote at the end of the document.
What I need is deleting the semi-colons from the main text and leave the
[^3]:
[^15]:
etc.
references at the end intact.
Because the main text references come after a word or at the end of a sentence (ususally before the sentence-ending period), there is never a case a reference would start a sentence (even if they seem to appear there once or twice because of word wrap).
I provided the exact opposite of my needs here:
Click here for Regex101 website link
I put in the exact opposite of what I want because I already knew of the
^
sign to match anything that is at the front of the line.
Now I would like to negate this, if possible, so that I would delete the semi-colons in the main text, not down at the bottom.
Of course, it is likely that my approach is not good and you'll come up with a completely different approach. Especially because there doesn't seem to be a NOT operator in Regex, if I read correctly.
I repeat: the Regex101 example with the match and substitution is exactly the opposite of what I want.
I am not sure if you can play around in the substitution line to get the desired negative effect.
I could have probably asked for removing the first occurence of semi-colons but I thought the important part of tackling the problem is that those items not to be matched are always at the start of the line, not the others.
Thanks for any suggestions
In Notepad++ you might use a negative lookabehind asserting not the start of the string to the left, and use \K to clear the match buffer matching only the colon that should be replaced by an empty string.
(?<!^)\[\^\d{1,2}]\K:
Explanation
(?<!^) Negative lookbehind, assert not the start of the start directly to the left
\[\^ Match [^
\d{1,2} Match 1 or 2 digits
] Match literally
\K Forget what is matched so far
: Match a colon
Regex demo
There seems to be a bug in the Notepad++ find/replace behaviour when using a backreference to find duplicate lines that may not necessarily be consecutive. I'm wondering if anyone knows what the issue could be with the regex or if they know why the regex engine might be bugging out?
Details
I wanted to use a regex to find duplicate lines in Notepad++. The duplicates needn't necessarily be contiguous i.e. on consecutive lines, there can be lines in between. I started with this post:
https://medium.com/#heitorhherzog/compare-sort-and-delete-duplicate-lines-in-notepad-2d1938ed7009
But realised that the regex mentioned there only checks for contiguous duplicates. So I wrote my own regex:
^(.+)$(?:(?:\s|.)+)^(\1)$
The above basically captures something on a whole line, then matches a load of stuff in between, then captures the same thing about on a line.
What's wrong
The regex works, but only sometimes. I can't figure out the pattern. I've whittled it down to this so far. If I do a "Replace All" on the replacement pattern \1\2 then the "replace all" leaves me with just line 3, which is "elative backreferences32". This is wrong:
dasfdasfdsfasdfasdfadsfasdf
elative backreferenceswe
elative backreferences32
elative backreferencesd
elative backreferencdesdfdasdfsdafsd
asfasdfasdfasdfasdfasfdsaasdfas
asdfasdfafds asdfasfdsafasd asdfdasfsd
elative backreferencessfhdfg
x
y
x
But if I delete any line from that file, then only the consecutive lines x then y then x are replaced by a single line xx as I'd expect.
Notes
I'd like to keep this question focused mostly on why the regex is
bugging out. Suggestions about alternative ways to find duplicate
lines are of course good but the main reason I'm asking this is to
figure out what's going on with the regex and Notepad++.
I don't really need the replace part of this, just the find, I was just using the replace to try to figure out what groups were being captured in an attempt to debug this
The find behaviour is also buggy. I noticed this first actually. It first finds the match I'm actually looking for, and then if I click "Find Next" again, it highlights all the text.
Hypotheses
There is a bug in Notepad++ v7.8.4 64 bit. I just updated today so maybe they haven't caught it yet.
Does the in-between part of the match, (?:(?:\s|.)+), maybe cycle
around past the end of file character and loop right back to the
original match? If so, I'd say that's still a bug, because AFAIK a
regex should only consume each character once.
I thought there might be a limit to the number of characters in the file, but I disproved this hypothesis by playing around with the file, adding characters here and there. Two files with the same number of lines and the same number of characters can behave differently: one with buggy behaviour, one without.
Screenshots
Before
After Without Matches Newline (The intended configuration)
After With Matches Newline (for Experimentation)
(?:\s|.) should be avoid as it causes unexpected behaviour, I suggest using [\s\S] instead:
Find what: ^(.+)$[\s\S]+?^(\1)$
Replace with: $1$2
I'm trying to grab 2 items from a simple line.
[Title](Description)
EDIT: actually a url looking to display called it description because i want it displayed not actually parsed.
[Trivium](https://www.youtube.com/user/trivium)
Grabbing between the brackets (...) doesn't seem to work at all for me. I've googled and found several variations with no luck, Thanks in advance :)
EDIT:
Tried the following:
[(.+?)]\((.*)\)
[(.+?)]\([^\(\r\n]*\)
[(.+?)]((.+?))
and a cpl more I cant find again
The first regex you listed almost has it right. Try using this regex instead:
\[.+?\]\((.*)\)
As #PM 77-1 pointed out, you need to escape the brackets by placing a backslash in front of them. The reason for this is that brackets are special regex metacharacters, or characters which have a special meaning. Brackets tell the regex engine to look for classes of characters contained inside of it.
Your original regex [(.+?)]\((.*)\) is actually doing this:
[(.+?)] match a period '.' 1 or more times
\((.*)\) match (anything), i.e. anything contained in parentheses
So this regex would match .....(stuff) but would not match [Title](Description), the latter which is what you really want.
Here is a link where you can test out the working regex:
Regex 101
I'm trying to find a regex for removing everything after the last dot in a file. So far I've found ways to remove all text before the first dot, but I can't seem to find a way to select the end of the file. Could you help me on the way?
Thanks in advance
You can try something like:
\.[^.]*$
to match everything including and after the last dot. If you don't want to include the last dot, then you can use a positive lookbehind:
(?<=\.)[^.]*$
Try following regex for search and replace
s/\.[^.]*$/\./
On Bigquery, r'([^.]+).?$' works, if you want to remove the last dot.