I am still not so used to the vim regex syntax. I have this code:
rename_column :keywords, :textline_two_id_4, :textline_two_id_4
I would like to match the last id with a positive lookahead in VIMs regex syntax.
How would you do this?
\id#=_\d$
This does not work.
This perl syntax works:
id(?=_\d$)
Edit - the answer:
/id\(_\d$\)\#=
Can someone explain the syntax?
If you check the vim help, there is not much to explain: (:h \#=)
\#= Matches the preceding atom with zero width. {not in Vi}
Like "(?=pattern)" in Perl.
Example matches
foo\(bar\)\#= "foo" in "foobar"
foo\(bar\)\#=foo nothing
This should match the last id:
/id\(_\d$\)\#=
save some back slashes with "very magic":
/\vid(_\d$)#=
actually, it looks more straightforward to use vim's \zs \ze:
id\ze_\d$
Related
I am looking for a regex which does not match "CVS". I don't want to use any feature which cannot translate into Emacs regex.
So far I have (in Python syntax, because I want to show it on regex101.com):
(^[^C].*|^.[^V].*|^..[^S].*)
This regex does not match "CVS" - so far so good. Unfortunately it does not match "CVS and more" either, but it should match it.
How can I adjust my regex to match "CVS and anything after it", but still not match "CVS"? (I.e how can I make the last test on the regex101.com page succeed?)
My understanding is that you want to match every individual line which isn't the line:
CVS
You're not too far off with your attempt.
Here the regex in Python syntax on regex101.com:
^(?:[^C\n]|C[^V\n]|CV[^S\n]|CVS.).*|^CV?$
And here's an elisp regexp in the read syntax for strings:
"^\\(?:[^C\n]\\|C[^V\n]\\|CV[^S\n]\\|CVS.\\).*\\|^CV?$"
Note the newlines. So in string syntax it becomes:
^\(?:[^C
]\|C[^V
]\|CV[^S
]\|CVS.\).*\|^CV?$
n.b. You can use M-x re-builder to test these in Emacs.
First of all let me apologize for asking this question again. I tried to find the answer, but drew a blank. I want to switch the order of words in a file such as: "dutch, abe - a blank sheet" to "abe dutch - a blank sheet". I'm using regular expressions and I seem to remember it's something like 1, 3, 2. Anyway, thank you in advance.
If each string is on newline you can try like this:
Find:
^(\w+),\s*(\w+)(.*)
Replace:
\2 \1\3
Demo:
https://regex101.com/r/SpKOHE/3
Regex:
(\w+) Match 1 or as many word characters and capture in group.
\s* Match 0 or as many whitespaces.
(.*) Match evertything till the end of line.
Try the following regex pattern:
^(\w+),?\s+?(\w+)(.*)
The substitution order is:
$2, $1$3
https://regex101.com/r/T3c77x/1
You can use ^([a-zA-Z]+),?\s*?([a-zA-Z]+)(.*)$ and then modify your initial string to produce the output as $2, $1$3.
I don't know which language are you using for regex or I would have written the complete code here for you. But the logic will be similar to above.
demo
I have a problem with following expression in vim.
In text: AekwoeuwioeuwioeuwB_AewieuiwuiweuB-A32r3r3hruh3u2huB A32r3r3hruh3u2huB I would like to select A-B strings separately. Something which is achievable by A.*?B in standard regex. However I am not able to do this in vim.
The syntax for the non-greedy "zero or more" match A.*?B in Vim is A.\{-}B. See :help /\{-.
An overview of the main differences to Perl's regular expression dialect can be found at :help perl-patterns.
Alternative
For simple patterns, the end delimiter can be excluded from the range, so that the default greedy matching will work, too: A[^B]*B
I'm using vim daily for manipulating text and to write code. However, every time I have to perform any substitution, or do any kind of regex work, it drives me crazy, and I have to switch to sublime. I'd like to know, what's the correct way of turning this:
<img src="whatever.png"/>
<img src="x.png"/>
into
<img src="<%= image_path("whatever.png") %>"/>
<img src="<%= image_path("x.png") %>"/>
In sublime, I can use this as the regex for search: src="(.*?.png)" and this as the regex for substitution: src="<%= asset_path("\1") %>". In vim, if I do this: :%s/\vsrc="(.*?.png)/src="<%= asset_path("\1") %>"/g I get:
E62: Nested ?
E476: Invalid command
What am I not doing right?
As #nhahtdh stated Vim's dialect of regex uses \{-} as the non-greedy quantifier. If you use the very magic flag it is just {-}. So your command turns into:
:%s/\vsrc="(.{-}.png)/src="<%= asset_path("\1") %>"/g
However you didn't escape the . in .png so:
:%s/\vsrc="(.{-}\.png)/src="<%= asset_path("\1") %>"/g
But we can still do better! By using \zs and \ze we can avoid retyping the src=" bit. \zs and \ze mark the start and end of the match where the substitution will occur.
:%s/\vsrc="\zs(.\{-}\.png)"/<%= image_path("\1") %>"/g
However we still are not done because we can take it one step further if we carefully choose where we put \zs and \ze then we can use vim's & in the substitution. It is like \0 in Perl's regex syntax. Now we don't need any capture groups which nullifies the need for the very magic flag.
:%s/src="\zs.\{-}\.png\ze"/<%= image_path("&") %>/g
For more help see the following documentation:
:h /\zs
:h /\{-
:h s/\&
According to this website, the syntax for lazy quantifier in vim is different from the syntax used in Perl-like regex.
Let me quote the website:
*/\{-*
\{-n,m} matches n to m of the preceding atom, as few as possible
\{-n} matches n of the preceding atom
\{-n,} matches at least n of the preceding atom, as few as possible
\{-,m} matches 0 to m of the preceding atom, as few as possible
\{-} matches 0 or more of the preceding atom, as few as possible
{Vi does not have any of these}
n and m are positive decimal numbers or zero
*non-greedy*
If a "-" appears immediately after the "{", then a shortest match
first algorithm is used (see example below). In particular, "\{-}" is
the same as "*" but uses the shortest match first algorithm.
:%s/"\(.*\)"/"<%= image_path("\1") %>"/g
The double quotes are out main pattern. Everything we want to capture gets thrown into a group \( \) so we can later relate to it via \1.
If you use very magic, you have to escape the =, thus \vsrc\=(.*).png". So using your way the answer is:
:%s/\vsrc\="(.*\.png)"/src="<%= image_path("\1") %>"/g
It's easy to see if you :set hlsearch and then play around with /. :)
I have the following in a text file:
This is some text for cv_1 for example
This is some text for cv_001 for example
This is some text for cv_15 for example
I am trying to use regex cv_.*?\s to match cv_1, cv_001, cv_15 in the text. I know that the regex works. However, it doesn't match anything when I try it in Vim.
Do we need to do something special in Vim?
The non-greedy character ? doesn't work in Vim; you should use:
cv_.\{-}\s
...instead of:
cv_.*?\s
Here's a quick reference for matching:
* (0 or more) greedy matching
\+ (1 or more) greedy matching
\{-} (0 or more) non-greedy matching
\{-n,} (at least n) non-greedy matching
vim's regex syntax is a little different -- what you're looking for is
cv_.\{-}\s
(the \{-} being the vim equivalent of perl's *?, i.e., non-greedy 0-or-more). See here for a good tutorial on vim's regular expressions.