Develop Reference

Ignore nested single quotes inside of single quotes

I'm working with matching an entire string within single quotes. The problem is, these strings are dynamically generated and I need to ignore all other single quotes within the first set of quotes. I've come across other solutions that are similar but I can't seem to tweak them to my needs.
Here is what I've worked with so far:
'(?:''|[^'])*'
I would like to match essentially everything within the first and last single quotes between content: and ;
Some example text:
#bottom {
content: 'Here we have an embedded unescaped 'single' that is generated at runtime. {Let's ignore it
please'
;
}
This is the playground I've been working in:
https://regex101.com/r/ITHciu/2
Any help would be greatly appreciated.

If you absolutely have to use Regexes for this and you are certain that ; will not be inside the string you are searching for, you could try this: '[^;]*'\s*;$. It will select everything from a ' and go until a like that ends with whitesapce and a ;.
Edit: if you need the stuff between the ' and ';, you could use a group '([^;]*)'\s*;$.
However, a much cleaner solution would be to make a little parser, that will read the string char by char. It's a fun exercise if you got a little bit more time.
If nothing else, you could use that regex to correct the invalid syntax in your files. And tell the people manually writing them what the valid syntax should be.

How do I see if a string contains another string with quotes in it?

I am trying to see if a large string contains this line of HTML:
<label ng-class="choiceCaptionClass" class="ng-binding choice-caption">Was this information helpful?</label>
As you can see, this snippet has quotations in multiple places and it's causing problems when I do something like this:
Assert.IsTrue(responseContent.Contains("<label ng-class="choiceCaptionClass" class="ng - binding choice - caption">Was this information helpful?</label>"));
I've tried both of these ways of defining the string:
#"<label ng-class=""choiceCaptionClass"" class=""ng - binding choice - caption"">Was this information helpful?</label>"
and
"<label ng-class=\"choiceCaptionClass\" class=\"ng - binding choice - caption\">Was this information helpful?</label>"
But in each case the Contains() method looks for the literal string with either the double quotes or the backslashes. Is there another way I could define this string so I can correctly search for it?

Escaping the double-quotes with backslashes is the proper thing to do.
The reason your search may be failing is that the strings don't actually match. For example, in your version with backslashes, you have spaces around some of the dashes but your HTML string does not.

Try using regular expressions. I made this one for you but you can test your own regex here.
var regex = new Regex(#"<label\s+ng-class\s*=\s*""choiceCaptionClass""\s+class\s*=\s*""ng-binding choice-caption""\s*>\s*Was this information helpful\?\s*</label>", RegexOptions.IgnoreCase);
Assert.IsTrue(regex.IsMatch(responseContent));
If this is not working use the tester tool to figure it out what part of the pattern is getting off.
Hope this help!

Regular Expression for Digits and Special Characters - C#

I use Html-Agility-Pack to extract information from some websites. In the process I get data in the form of string and I use that data in my program.
Sometimes the data I get includes multiple details in the single string. As the name of this Movie "Dog Eats Dog (2012) (2012)". The name should have been "Dog Eats Dog (2012)" rather than the first one.
Above is the one example from many. In order to correct the issue I tried to use string.Distinct() method but it would remove all the duplicate characters in the string as in above example it would return "Dog Eats (2012)". Now it solved my initial problem by removing the 2nd (2012) but created a new one by changing the actual title.
I thought my problem could be solved with Regex but I have no idea as to how I can use it here. As far as I know if I use Regex it would tell me that there are duplicate items in the string according to the defined Regex code.
But how do I remove it? There can be a string like "Meme 2013 (2013) (2013)".
Now the actual title is "Meme 2013" with year (2013) and the duplicate year (2013). Even if I get a bool value indicating that the string has duplicate year, I cant think of any method to actually remove the duplicate substring.
The duplicate year always comes in the end of the string. So what should be the Regex that I would use to determine that the string actually has two years in it, like (2012) (2012)?
If I can correctly identify the string contains duplicate maybe I can use string.LastIndexOf() to try and remove the duplicate part. If there is any better way to do it please let me know.
Thanks.

The right regex is "( \(\d{4}\))\1+".
string pattern = #"( \(\d{4}\))\1+";
new Regex(pattern).Replace(s, "$1");
Example here : https://repl.it/Evcy/2
Explanation:
Capture one " (dddd)" block, and remove all following identical ones.
( \(\d{4}\)) does the capture, \1+ finds any non empty sequence of that captured block
Finally, replace the initial block and its copies by the initial block alone.

This regex will allow for any pattern of whitespace, even none, as in (2013)(2013)
`#"(\(\d{4}\))(?:\s*\1)+"`
I have a demo of it here

Regular Expression to match a quoted string embedded in another quoted string

I have a data source that is comma-delimited, and quote-qualified. A CSV. However, the data source provider sometimes does some wonky things. I've compensated for all but one of them (we read in the file line-by-line, then write it back out after cleansing), and I'm looking to solve the last remaining problem when my regex-fu is pretty weak.
Matching a Quoted String inside of another Quoted String
So here is our example string...
"foobar", 356, "Lieu-dit "chez Métral", Chilly, FR", "-1,000.09", 467, "barfoo", 1,345,456,235,231, "935.18"
I am looking to match the substring "chez Métral", in order to replace it with the substring chez Métral. Ideally, in as few lines of code as possible. The final goal is to write the line back out (or return it as a method return value) with the replacement already done.
So our example string would end up as...
"foobar", 356, "Lieu-dit chez Métral, Chilly, FR", "-1,000.09", 467, "barfoo", 1,345,456,235,231, "935.18"
I know I could define a pattern such as (?<quotedstring>\"\w+[^,]+\") to match quoted strings, but my regex-fu is weak (database developer, almost never use C#), so I'm not sure how to match another quoted string within the named group quotedstring.
FYI: For those noticing the large integer that is formatted with commas but not quote-qualified, that's already handled. As is the random use of row-delimiters (sometimes CR, sometimes LF). As other problems...

Replace with this regex
(?<!,\s*|^)"([^",]*)"
now replace it with $1
try it here
escaping " with "" it would become
(?<!,\s*|^)""([^"",]*)""

Regex between, from the last to specific end

Today my wish is to take text form the string.
This string must be, between last slash and .partX.rar or .rar
First I tried to find edge's end of the word and then the beginning. After I get that two elements I merged them but I got empty results.
String:
http://hosting.xyz/1234/15-game.part4.rar.html
http://hosting.xyz/1234/16-game.rar.html
Regex:
Begin:(([^/]*)$) - start from last /
End:(.*(?=.part[0-9]+.rar|.rar)) stop before .partX.rar or .rar
As you see, if I merge that codes I won't get any result.
What is more, "end" select me only .partX instead of .partX.rar
All what I want is:
15-game.part4.rar and 16-game.rar
What i tried:
(([^/]*)$)(.*(?=.part[0-9]+.rar|.rar))
(([^/]*)$)
(.*(?=.part[0-9]+.rar|.rar))
I tried also
/[a-zA-Z0-9]+
but I do not know how select symbols.. This could be the easiest way. But this select only letters and numbers, not - or _.
If I could select symbols..

You don't really need a regex for this as you can merely split the url on / and then grab the part of the file name that you need. Since you didn't mention a language, here's an implementation in Perl:
use strict;
use warnings;
my $str1="http://hosting.xyz/1234/15-game.part4.rar.html";
my $str2="http://hosting.xyz/1234/16-game.rar.html";
my $file1=(split(/\//,$str1))[-1]; #last element of the resulting array from splitting on slash
my $file2=(split(/\//,$str2))[-1];
foreach($file1,$file2)
{
s/\.html$//; #for each file name, if it ends in ".html", get rid of that ending.
print "$_\n";
}
The output is:
15-game.part4.rar
16-game.rar

Nothing could be simpler! :-)
Use this:
new Regex("^.*\/(.*)\.html$")
You'll find your filename in the first captured group (don't have a c# compiler at hand, so can't give you working sample, but you have a working regex now! :-) )
See a demo here: http://rubular.com/r/UxFNtJenyF

I'm not a C# coder so can't write full code here but I think you'll need support of negative lookahead here like this:
new Regex("/(?!.*/)(.+?)\.html$");
Matched Group # 1 will have your string i.e. "16-game.rar" OR "15-game.part4.rar"

Use two regexes:
start to substitute .*/ with nothing;
then substitute \.html with nothing.
Job done!