Regular expression - secong group of digits - c#

Hi I would like to pull second group of digits which are after (-) from below string:
D:\data\home\Logs_Audit\VO12_LAB_20140617-000301.txt
I used \d{8} to pull 20140617 but now I want to pull 000301
EDIT 1:
Now I would Like to pull VO12_LAB from above string. Could You please help me.
I am not good at regular expression and I didn't find good tutorial to understand it.
EDIT 2:
I found that something like
\w{2,3}\d{2,3}_\w{2,3}
works to me. Do you think it is accurate enough?

You can use lookahead/lookbehind to find the group based on "anchors", like this:
(?<=[-])\\d+(?=[.]txt)
The groups before and after the \\d+ are non-capturing zero-width "markers", in the sense that they do not consume any characters from the string, only describe character combinations that need to precede and/or follow the text that you would like to match.

You can use a Positive Lookahead for this.
\d+(?=\.)
Explanation: This matches digits (1 or more times) preceded by a dot .
\d+ digits (0-9) (1 or more time)
(?= look ahead to see if there is:
\. '.'
) end of look-ahead
Live Demo
Final Solution:
String s = #"D:\data\home\Logs\V_LAB_20140617-000301.txt";
Match m = Regex.Match(s, #"\d+(?=\.)");
if (m.Success) {
Console.WriteLine(m.Value); //=> "000301"
}

You can use this regex:
(?<=-)(\d+)
The first group will contain the digits.
Live Demo

Related

C# Regex to obtain string up until a pattern

I've always been really bad when it comes to using regular expressions but it is something I want to seriously understand because as we all know, it is quite useful.
This is for a personal project, to keep my folders organized and neat.
I have a bunch of folders with the following naming pattern XXXXXXXX.XXXXXXX.XXXXXX.SYY.EYY.SOMETHINGELSE
There can be any amount of X repeating separated by ".", but the SYY.EYY is always there. So what I want is a regular expression to retrieve all the text represented by XXX without the "." if possible up until the SYY.EYY pattern.
I managed to detect the pattern because YY are always numbers, so doing something like \d{2} will detect it but I'm wondering if its possible to also add the rest of the pattern to that \d{2}.
Any help is appreciate it :)
If the YY is as you stated 2 digits and you want to get the text except the . up until for example S11.E22 you could make use of the \G anchor and a capturing group to get the text without a dot.
The value is in the Match.Groups property.
\G(?!S[0-9]{2}\.E[0-9]{2})([^.]+)\.
In parts
\G Assert position at the end of previous match (start at the beginning)
(?! Negative lookahead, assert what is directly to the right is not
S[0-9]{2}\.E[0-9]{2} Math S, 2 digits, . E and 2 digits
) Close lookahead
( Capture group 1
[^.]+ Match 1+ times any char except a dot
) Close group 1
\. Match dot literal
Regex demo | C# demo
For example
string pattern = #"\G(?!S[0-9]{2}\.E[0-9]{2})([^.]+)\.";
string input = #"XXXXXXXX.XXXXXXX.XXXXXX.S11.E22.SOMETHINGELSE";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine(m.Groups[1].Value);
}
Output
XXXXXXXX
XXXXXXX
XXXXXX
You can "replace/cut" the "." with C#.
The regex to get up until the SYY.EYY can be like this:
.SYY.EYY$
Line ends with word -> Regex: ExampleWord$
I would do something like:
var leftPart = Regex.Match(x, "^.*?(?=SYY)").Captures.First().Value;
// this now has XXXXXXXX.XXXXXXX.XXXXXX.
// And we can:
var left = leftPart.Replace(".", " "); // or any other char

How to match a string between <>?

I tried \w+\:(\w+\-?\.?(\d+)?) but that is not correct
I have following text
<staticText:HelloWorld>_<xmlNode:Node.03>_<date:yyy-MM-dd>_<time:HH-mm-ss-fff>
The end result I want is something like the following
["staticText:HelloWorld", "xmlNode:Node.03","date:yyy-MM-dd","time:HH-mm-ss-fff"]
You could use the following regex.
<(.*?)>
Then have a look at how groups work to retrieve the result.
Regex rx = new Regex("<(.*?)>");
string text = "<staticText:HelloWorld>_<xmlNode:Node.03>_<date:yyy-MM-dd>_<time:HH-mm-ss-fff>";
MatchCollection matches = rx.Matches(text);
Console.WriteLine(matches.Count);
foreach(Match match in matches){
var groups = match.Groups;
Console.WriteLine(groups[1]);
}
This line should be able to match the content:
<(.*?)>
It will catch the arrows at the end which you don't seem to want, but you could remove them after words without regex.
You should consider a website like https://regexr.com - it helps exponentially in writing regex by allowing you to paste your cases and see how it works with them.
Matches any string within the <>. Hope this helps.
<(.*?)>
Your pattern does not match the 3rd and the 4th part of the example data because in this part \w+\-?\.?(\d+)? the dash and the digits match only once and are not repeated.
For your example data, you might use a character class [\w.-]+to match the part after the colon to make the match a bit more broad:
<(\w+\:[\w.-]+)>
Regex demo | C# demo
Or to make it more specific, specify a pattern for either the Node.03 part and for the year month date hour etc parts using a repeated pattern.
<(\w+\:\w+(?:\.\d+|\d+(?:-\d+)+)?)>
Explanation
< Match <
( Capturing group
\w+\:\w+ Match 1+ word chars, : and 1+ word chars
(?: Non capturing group
\.\d+ Match . and 1+ digits
| Or
\d+(?:-\d+)+ Match 1+ digits and repeat 1+ times matching - and 1+ digits
)? Close non capturing group and make it optional
) Close capturing group
>
Regex demo | C# Demo

Regex to insert and replace characters in a string C#

I have a string which looks like this :-
"$.ConfigSettings.DatabaseSettings.DatabaseConnections.SqlConnectionString.0.Id"
and I want the result to look like this :-
"$.ConfigSettings.DatabaseSettings.DatabaseConnections.SqlConnectionString[0].Id"
Basically wherever there is a single digit preceded and succeeded by a period I need to change it to [digit] followed by period ie [digit]. .I have seen tons of examples where people are only replacing the regex string.
How will I do this using Regex.Replace in C#
Regex.Replace(input, #"\.(\d)(?=\.)", "[$1]")
\. - capture a "."
(\d) - then a single digit in a capturing group ($1 in the replacement)
(?= - start a positive lookahead
\. - that matches a "."
) - end the lookahead
So, it means : (match a dot followed by a digit in a capturing group) only if it is followed by a dot
So we matched ".0" and captured "0". We replace the entire match with "[$1]", where $1 refers to the first captured group.
See "Grouping Constructs in Regular Expressions" : https://msdn.microsoft.com/en-us/library/bs2twtah(v=vs.110).aspx for information about the different grouping constructs that I use in this solution.

Regex pattern in C# with empty space

I am having issue with a reg ex expression and can't find the answer to my question.
I am trying to build a reg ex pattern that will pull in any matches that have # around them. for example #match# or #mt# would both come back.
This works fine for that. #.*?#
However I don't want matches on ## to show up. Basically if there is nothing between the pound signs don't match.
Hope this makes sense.
Thanks.
Please use + to match 1 or more symbols:
#+.+#+
UPDATE:
If you want to only match substrings that are enclosed with single hash symbols, use:
(?<!#)#(?!#)[^#]+#(?!#)
See regex demo
Explanation:
(?<!#)#(?!#) - a # symbol that is not preceded with a # (due to the negative lookbehind (?<!#)) and not followed by a # (due to the negative lookahead (?!#))
[^#]+ - one or more symbols other than # (due to the negated character class [^#])
#(?!#) - a # symbol not followed with another # symbol.
Instead of using * to match between zero and unlimited characters, replace it with +, which will only match if there is at least one character between the #'s. The edited regex should look like this: #.+?#. Hope this helps!
Edit
Sorry for the incorrect regex, I had not expected multiple hash signs. This should work for your sentence: #+.+?#+
Edit 2
I am pretty sure I got it. Try this: (?<!#)#[^#].*?#. It might not work as expected with triple hashes though.
Try:
[^#]?#.+#[^#]?
The [^ character_group] construction matches any single character not included in the character group. Using the ? after it will let you match at the beginning/end of a string (since it matches the preceeding character zero or more times. Check out the documentation here

regex for capturing digits and digit ranges

i have the following string
Fat mass loss was 2121,323.222 greater for GPLC (2–2.4kg vs. 0.5kg)
i want to capture
212,323.222
2-2.24
0.5
i.e. i want the above three results from the string,
can any one help me with this regex
I noticed that your hyphen in 2–2.4kg is not really hyphen, its a unicode 0x2013 "DASH".
So, here is another regex in C#
#"[0-9]+([,.\u2013-][0-9]+)*"
Test
MatchCollection matches = Regex.Matches("Fat mass loss was 2121,323.222 greater for GPLC (2–2.4kg vs. 0.5kg)", #"[0-9]+([,.\u2013-][0-9]+)*");
foreach (Match m in matches) {
Console.WriteLine(m.Groups[0]);
}
Here is the results, my console does not support printing unicode char 2013, so its "?" but its properly matched.
2121,323.222
2?2.4
0.5
Okay I didn't notice the C# tag until now. I will leave the answer but I know that's not what you expected, see if you can do something with it. Perhaps the title should have mentioned the programming language?
Sure:
Fat mass loss was (.*) greater for GPLC \((.*) vs. (.*)kg\)
Find your substrings in \1, \2 and \3.
If for Emacs, swap all parentheses and escaped parentheses.
How about something like this:
^.*((?:\d+,)*\d+(?:\.\d+)?).*(\d+(?:\.\d+)?(?:-\d+(?:\.\d+))?).*(\d+(?:\.\d+)).*$
A little more general, I think. I'm a little concerned about .* being greedy.
Fat mass loss was 2121,323.222 greater
for GPLC (2–2.4kg vs. 0.5kg)
a generalized extractor:
/\D+?([\d\,\.\-]+)/g
explanation:
/ # start pattern
\D+ # 1 or more non-digits
( # capture group 1
[\d,.-]+ # character class, 1 or more of digits, comma, period, hyphen
) # end capture group 1
/g # trailing regex g modifier (make regex continue after last match)
sorry I don't know c# well enough for a full writeup, but the pattern should plug right in.
see: http://www.radsoftware.com.au/articles/regexsyntaxadvanced.aspx for some implementation examples.
I came out with something like this atrocity:
-?\d(?:,?\d)*(?:\.(?:\d(?:,?\d)*\d|\d))?(?:[–-]-?\d(?:,?\d)*(?:\.(?:\d(?:,?\d)*\d|\d))?)?
Out of witch -?\d(?:,?\d)*(?:\.(?:\d(?:,?\d)*\d|\d))? is repeated twice, with – in the middle (note that this is a long hyphen).
This should take care of dots and commas outside of numbers, eg: hello,23,45.2-7world - will capture 23,45.2-7.
It looks like you're trying to find all numbers in the string (possibly with commas inside the number), and all ranges of numbers such as "2-2.4". Here is a regex that should work:
\d+(?:[,.-]\d+)*
From C# 3, you can use it like this:
var input = "Fat mass loss was 2121,323.222 greater for GPLC (2-2.4kg vs. 0.5kg)";
var pattern = #"\d+(?:[,.-]\d+)*";
var matches = Regex.Matches(input, pattern);
foreach ( var match in matches )
Console.WriteLine(match.Value);
Hmm, this is a tricky question, especially because the input string contains unicode character – (EN DASH) instead of - (HYPHEN-MINUS). Therefore the correct regex to match the numbers in the original string would be:
\d+(?:[\u2013,.]\d+)*
If you want a more generic approach would be:
\d+(?:[\p{Pd}\p{Pc}\p{Po}]\d+)*
which matches dash punctuation, connecter punctuation and other punctuation. See here for more information about those.
An implementation in C# would look like this:
string input = "Fat mass loss was 2121,323.222 greater for GPLC (2–2.4kg vs. 0.5kg)";
try {
Regex rx = new Regex(#"\d+(?:[\p{Pd}\p{Pc}\p{Po}\p{C}]\d+)*", RegexOptions.IgnoreCase | RegexOptions.Multiline);
Match match = rx.Match(input);
while (match.Success) {
// matched text: match.Value
// match start: match.Index
// match length: match.Length
match = match.NextMatch();
}
} catch (ArgumentException ex) {
// Syntax error in the regular expression
}
Let's try this one :
(?=\d)([0-9,.-]+)(?<=\d)
It captures all expressions containing only :
"[0-9,.-]" characters,
must start with a digit "(?=\d)",
must finish with a digit "(?<=\d)"
It works with a single digit expression and does not include beginning or trailing [.,-].
Hope this helps.
I got the solution to my problem.
The following is the Regex that gave my desired result:
(([0-9]+)([–.,-]*))+

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