I am using the following regex to remove items in a sentence that falls within brackets
\(.*?\)
So in this sentence anything between (DFKJERLjDLJLF) gets removed.
But if there are more than one brackets in a sentence, I want to target only the last bracket. How do I change my regex?
So in this sentence (only) the last bracket and its contents (DFKJERLjDLJLF) gets removed.
Update: I tried using \s\([^)]+\)$ in my regex tool but it is not matching
Here is the example
.*(\(.*?\))
.* matches every character and moves the position to the end, when it bounce back
and then (\(.*?\)) find the first match in (), i.e. the last match from the start.
A python solution to this is:
def remove_last_brackets(string):
return re.sub(r'^(.*)\(.*?\)?([^()]*)$', lambda x: x.group(1) + x.group(2), string)
This is hard to answer without language context.
The global flag, supported on most regex systems, allows you to match all occurrences of a string directly.
Alternatively, you could store the first location of a match and then start future searches at that location, and repeat until there are no matches.
Related
I have a file where classnames were gives as
{styles.classname}
I have to change all the occurences like above to below
"classname"
I tried matching in the following way which matches the occurences
\{+[styles]+\.+([\w])+\}
The problem is with replace. I used \1 in replace with. But it doesn't replace the whole word but replaces it with only the last letter of the word
e
The problem is more than what you inspected. You are using a character class in a wrong context. You don't need [styles]+ but styles alone. You probably don't need all those extra + quantifiers and ([\w])+ will result into the last char to be stored in capturing group one. Try:
\{styles\.(\w+)\}
I have a string like aaa**b***c****ddd, and I want to get a sequence of matched text of pattern [^*]\*+[^*], which should I thank be [a**b, b***c, c***d]. However, when I test this in text editor like vim or emacs, the second (b***c) is not matched.
aaa**b***c***ddd
|--| |---|
first third
|---|
second, which I think should be matched but not
How should I modify the regular expression to match the second?
Yes you can, the trick consists to put all in a capturing group inside a lookahead to allow overlapping results:
(?=([^*]\*+[^*]))
But you can't use this do to replacements since this pattern matches nothing. (or perhaps if you can get the capture group length and the current offset)
EDIT:
it seems to be possible to obtain the capture group length with vim with strlen(submatch(1))
#CommuSoft is correct. One way to approach this problem would be to match the whole string against this regex and then the second time around, you match this regex against the substring that starts at (index_of_first_previous_match + 1) until the end of the string. Hope that is clear.
So if the index of your first match above (a**b) was 2. Then the new substring that you match against the regex the second time should start from index 3 till the end of the string. This will give you the two results.
However, Casimir's answer is much simpler.
I'm writing a wildcard string in Word that should match:
{0>yadayada<}100{>yadayada<0}
Where yadayada can be anything EXCEPT the start of a new delimiter denoted by: {0>
This is what I have so far:
(\{0\>)*(\<\}100\{\>)*(\<0\})
This works except that the first '*' keeps matching tekst until it finds <}100{>yadayada<0}
I need to change it so that the * selects everything EXCEPT strings that contain '{0>'
I tried this by changing the first * with
[!(\{0>)]*
Or everything together:
(\{0\>)[!(\{0>)]*(\<\}100\{\>)*(\<0\})
But this evidently doesn't work.
Please help!
Try this:
\{0>.+?(?=\{0>)
You only need to escape the \{
What this regular expression says is:
Match all strings containging {0> then any text one or more times .+ and the ? at the end tells the regex engine to do a lazy search, since .+ will consume all characters if you let it. The lazy search says find the least amount of characters until the next part of the regex can take over.
Then the (?=\{0>) says to match the next deliminter but do not include it in selection.
Hope this helps!
I'm very new at regex, and to be completely honest it confounds me. I need to grab the string after a certain character is reached in said string. I figured the easiest way to do this would be using regex, however like I said I'm very new to it. Can anyone help me with this or point me in the right direction?
For instance:
I need to check the string "23444:thisstring" and save "thisstring" to a new string.
If this is your string:
I'm very new at regex, and to be completely honest it confounds me
and you want to grab everything after the first "c", then this regular expression will work:
/c(.*)/s
It will return this match in the first matched group:
"ompletely honest it confounds me"
Try it at the regex tester here: regex tester
Explanation:
The c is the character you are looking for
.* (in combination with /s) matches everything left
(.*) captures what .* matched, making it available in $1 and returned in list context.
Regex for deleting characters before a certain character!
You can use lookahead like this
.*(?=x)
where x is a particular character or word or string.{using characters like .,$,^,*,+ have special meaning in regex so don't forget to escape when using it within x}
EDIT
for your sample string it would be
.*(?=thisstring)
.* matches 0 to many characters till thisisstring
Here is a one-line solution for matching everything after "before"
print $1."\n" if "beforeafter" =~ m/before(.*)/;
Edit:
While using lookbehind is possible, it's not required. Grouping provides an easier solution.
To get the string before : in your example, you have to use [^:][^:]*:\(.*\). Notice that you should have at least one [^:] followed by any number of [^:]s followed by an actual :, the character you are searching for.
I'm searching the pattern (.*)\\1 on the text blabl with regexec(). I get successful but empty matches in regmatch_t structures. What exactly has been matched?
The regex .* can match successfully a string of zero characters, or the nothing that occurs between adjacent characters.
So your pattern is matching zero characters in the parens, and then matching zero characters immediately following that.
So if your regex was /f(.*)\1/ it would match the string "foo" between the 'f' and the first 'o'.
You might try using .+ instead of .*, as that matches one or more instead of zero or more. (Using .+ you should match the 'oo' in 'foo')
\1 is the backreference typically used for replacement later or when trying to further refine your regex by getting a match within a match. You should just use (.*), this will give you the results you want and will automatically be given the backreference number 1. I'm no regex expert but these are my thoughts based on my limited knowledge.
As an aside, I always revert back to RegexBuddy when trying to see what's really happening.
\1 is the "re-match" instruction. The question is, do you want to re-match immediately (e.g., BLABLA)
/(.+)\1/
or later (e.g., BLAahemBLA)
/(.+).*\1/