regex to take string C from {A|B|C} [closed] - regex

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. See also: Stack Overflow question checklist
Closed 9 years ago.
Improve this question
Is there any regex master that can help me?
I have a list of words like {first|second|third}, and I want just the last word, in this case {first|second|third}.
Can anyone help me please??
Edit:
After feedback I am adding more information.
I have a sentence such as "I am going to France {today|tomorrow|next week}" for example. But I want only "I am going to France next week".
I tried (?<=\{).*?(?=\|.*?\}) but this gives me |tomorrow|next week, I just want next week without the vertical lines.
PS it doesn't necessarily have to 3 words, I just want the last regardless.

The regex you need is obviously:
((\w|\s)+)\}

A python test of the regex:
>>> import re
>>> test = """ds like {first|second|third}, and I want just t"""
>>> re.findall('\|([^\|]+)\}', test)
['third']

To generally replace {a|bc|def} with def with no nesting or other complications, search for the regex
\{[}]+\|([^|}]+)\}
and substitute with the first (and only) parenthesized subgroup. In Perl, that would be something like
s/\{[}]+\|([^|}]+)\}/$1/g;
Many other languages have a similar syntax, though it might be less compact. In PHP, look for preg_replace.
The expression looks complex, but isn't really; we look for a literal { followed by the longest possible string of characters which are not }, as long as it's followed by a literal | and (subgroup) a string of characters which are neither | nor }, and finally, after the subgroup, a literal }.

Try this
/\{.+?([^|]+?)\}/
(you can easily test it by typing the following in your browser's JS console)
"{first|second|third}".replace( /\{.+?([^|]+?)\}/, "$1")
or even
"I am going on the {first|second|third}".replace(/\{.+?([^|]+?)\}/, "$1")
-> "I am going on the third"

Related

How to extract a company name from this expression? [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 7 years ago.
Improve this question
I am struggling with what is most probably a very simple regular expression.
Consider this the text I wish to evaluate:
??Company=My Company Name Ltd??Address= 29 Acacia Road, Nuttytown, AA1 9AA??Description=A very rambling description here... goes on for a bit and then somemore??E-mail=bert#bertswork.com??Version=Super Plus??Expiration date=01/01/2026??First name=Bert??Last name=Bloggs??
I want to extract the string for My Company Name Ltd that is between the Company= and the ??Address= tags.
Please can some kind soul put me out of my misery!
You can try this
/(?<=\?{2}Company=)(.*?)(?=\?{2})/
I used lookbehind (?<=) and look ahead (?=) so that ??Company= and ?? is not included in the match.
Regex
Although we usually want to see what you've tried, I've been in your situation - A complete noob and not knowing even where to start, so hope this helps...
Since you know each tag starts with a ?, you can use the following:
\?\?Company\=([^?]*)
This basically says:
It starts with ??Company=
Take all the characters after that until you find the next ? character and place them in a capture group.
Hope that does the trick

$1 through $9 only in perl, can we go further? [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 8 years ago.
Improve this question
I have a requirement to match 12 numbers in a sequence but i am getting limited to 9th number. Is there any way to go beyond 9 matches ?
my string is something like
{"Column5": "Null", "Column4": "Null", "Column6": "Null", "Column1": "END", "Column3": "Null", "Column2": "Null"}
where columns are fixed but in place of Null there can be any sequence/characters.
I tried matching columns and subsequent strings but i have 12 matches whereas i am limited till only $9.
Any suggestions ?
You can easily put your matches into an actual array rather than relying on $1 and friends:
my #matches = $some_string =~ /(some) (regex) with (m)(a)(n)(y) (c)(a)(p)(t)(u)r(e)(s)/;
Or, as suggested in a comment, use a JSON parser if you're parsing JSON data. It will be more reliable than a quick regex-based solution.
Please use Dave Sherohman's suggestion about using a JSON parser, or at least use an actual array to store the matches.
Perl imposes no hard limit on the number of captures (or the limit is so high that no reasonable script would run into). The code in this answer and even the script in the question shows that you can refer to matched text in capturing group beyond 9 as usual, i.e. group 10 with $10, group 100 with $100.
(In case anyone is confused, $1, $10, ... are variables used outside the regex to refer to content of the capturing group. It's not syntax for backreference (e.g. \1, \10, ... or \g{1}, \g{10}, ...), which is used in the regex to match the same text captured by the capturing groups).

Match everything in a string after the 3rd '/' [closed]

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. See also: Stack Overflow question checklist
Closed 9 years ago.
Improve this question
I have two different forms of a string:
https://anexample.com/things/stuff
and
https:///things/stuff
I need a regular expression that will match everything in the string after the 3rd slash, no matter the syntax. Once it hits the 3rd slash, the rest of the string is matched. I have found a bunch of examples, but I can't seem to tweak the right way to get it to work. Thanks in advance.
You can use this
^[^/]*/[^/]*/[^/]*/(.*)$
You can use this regex:
^(?:[^\/]*\/){3}(.*)$
And use matched group #1
In javascript:
var s = 'https:///things/stuff';
m = s.match(/^(?:[^\/]*\/){3}(.*)$/);
// m[1] => things/stuff
Assuming PCRE, and that you won't have newlines in your string:
If the 3 slashes can be at any position (like your first example):
^[^/]/[^/]*/[^/]*/(.*)$
This could also be expressed as
^(:?[^/]*/){3}(.*)$
Using positive lookbehind, you could use the following, which should only match what you want instead of putting it into a capturing group:
(?<=^(:?[^/]*/){3}).*$
Any needed escaping due to used delimiters is left as an exercise to the reader of course ( if you use / as a delimiter, you have to escape all / in the expression, like \/)
And there's probably a million other alternatives, depending on what exact needs you have besides the ones you mentioned.
Something like this should work, however I'm writting it without any testing, but it should look for three sections of any character any number of times followed by slash and then catch last section which is everything until line end - you can of course change delimiter to whitespace or whatever.
^.*/{3}(.*$)

Regex expression to replace word before search pattern [closed]

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. See also: Stack Overflow question checklist
Closed 8 years ago.
Improve this question
I am very confused how to replace a word before pattern ".ext".
example :
Before Replace : abcd.ext.com
After Replace : customer.ext.com
You can use something like [^.]+(?=\.) as the match and replace it by customer.
(?=\.) is a positive lookahead which will match when there is a dot following the part before, but it won't match any characters on its own.
E.g. in C# you can use
Regex.Replace(foo, #"[^.]+(?=\.)", "customer");
If you're doing this in C# then I would recommend you just doing something like this:
var newFileName = fileName.Replace(Path.GetFileName(fileName), "newFileNameValue");
If it's in VB.NET, it would look almost exactly the same:
Dim newFileName As String = fileName.Replace(Path.GetFileName(fileName), "newFileNameValue")
You can use a Regex, but it's probably a little overkill and less stable. See, when building a Regex you have to break it down to a really abstract level. You need to handle every extension that's in your domain and that list can grow pretty quickly. So then it's generally not feasible to include those extensions in the Regex itself.
To further add to the problem, a valid file name might be something like this, MyFile.v1.l1.ext1.txt. The extension of that file is .txt, but grabbing that with a Regex is tough.
On Unix you can use sed like this:
echo "$str"|sed 's/abcd\(\.ext\)/customer\1/'
i.e. look for abcd immediately followed by .ext (capture this in a group). Then replace it with customer and match group #1 (.ext)
If you're using any other platform/language approach should be same.
perl
$x =~ s/(.*)(\.ext\.com)/customer$2/;

Helping users write regular expressions [closed]

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking us to recommend or find a tool, library or favorite off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. Instead, describe the problem and what has been done so far to solve it.
Closed 8 years ago.
Improve this question
I am working on a project where there are formatting rules for certain text fields.
Users are able to edit these rules. Currently, the rules are regular expressions. The users see regular expressions as very intimidating and would like an easier more user friendly way to write them.
I have in mind some simple translation tool... where users could enter # for a digit... X for a letter, etc.. But I know that the day will come when they need more than letters and digits.
I wonder if a simple translation tool exists or if there is a better way to do this?
Thank you for reading, all suggestions and ideas are welcome.
Split string into single characters and apply
Replace each X with [a-zA-Z]
Replace each # with \d
Replace each ^ with \^
All others replace with [*], where * is the character you are replacing
Join all patterns into one final regex pattern
If you want to apply regex pattern to the entire string, add ^ at the beginning and $ at the end.
It should be fairly straightforward to create a tool such as you are proposing. Simply expand your placeholders into corresponding regex values:
var input= "XX##*"
var regex = input.replace('#', '[0-9]')
regex = regex.replace('X', '[a-zA-Z]')
regex = regex.replace('*', '.*')
# etc
Of course, you will have to define your placeholders and any other options you want to provide your users. You could also get creative and allow power users to enter a regex directly by surrounding input with / (or some other identifier).
var input= '/\d\d\w\w.*/'
var regex = undefined;
if (input.matches('^/(.*)/$')) {
regex = $1 (group 1 from regex)
} else {
regex = input.replace('#', '[0-9]')
regex = regex.replace('X', '[a-zA-Z]')
regex = regex.replace('*', '.*')
}
Of course, this is entirely a made up language to demonstration the solution... If you find a way to compile it, I would be most interested. :)