RegEx to replace string in C# - c#

I'm really not great with RegEx in C#, never really used them but I have a long string that contains a lot of html that may contain numerous text parts like
src="Folder/Uploads/fd123051-532d-4804-a0fb-fd4ce6b70f7c/cd212dd7-7600-4b3f-a7d9-9a85c85a50ca.png"
or
src="Uploads/fd123051-532d-4804-a0fb-fd4ce6b70f7c/cd212dd7-7600-4b3f-a7d9-9a85c85a50ca.png"
I want to apply a reg ex over the string if it can be done in C# so it replaces the folder path so it will change any and all to be src = filename.extension
ie.
src="Uploads/fd123051-532d-4804-a0fb-fd4ce6b70f7c/cd212dd7-7600-4b3f-a7d9-9a85c85a50ca.png"
becomes
src="cd212dd7-7600-4b3f-a7d9-9a85c85a50ca.png"
Can anyone please help?

RegEx for your replace:
src="Uploads/fd123051-532d-4804-a0fb-fd4ce6b70f7c/cd212dd7-7600-4b3f-a7d9-9a85c85a50ca.png"
Will be:
F: src="(.+?)//(.+?)//(.+?).png" [You can check "Dot Matches All"]
R: src="$1/$2/$3.png" Or you can use instead of $1 , /1 /2 /3 etc.

You can use:
src = Path.GetFileName(src);

You need substring function that will take only the part which you want from string Please go here.
Get file name from path

Related

How to replace http://locallhost with ~/ in html string

I want to replace every "http://localhost:59455/" before "Images/TestFiles/(file name)" form my C# code below.
string tags = #"<p><img class='img - fluid' src='http://localhost:59455/Images/TestFiles/1.JPG'></p><p><br></p><p><img class='img-fluid' src='http://localhost:59455/Images/TestFiles/2.JPG'></p>";
string final = Regex.Replace(tags, "http.*/Images", "~/Images");
But it always give me wrong result like below:
<p><img class='img - fluid' src='~/Images/TestFiles/2.JPG'></p>
While I expected the result like:
<p><img class='img - fluid' src='~/Images/TestFiles/1.JPG'></p><p><br></p><p><img class='img-fluid' src='~/Images/TestFiles/2.JPG'></p>
You can see, it did replace only one.
Please help.
The * is greedy and matches everything from the first http to the last /Images. Add a ? to make it lazy:
http.*?/Images
More information on greedy and lazy quantifiers on MSDN
This Regex on Regex Storm
Be careful though, your regex will also match other paths that have /Images in them, like these for example:
http://localhost:59455/Whatever/Images
http://localhost:59455/ImagesButDifferent
So you might want to make it more restrictive.

Regex to Replace the end of the Url

I have a url something that follows a pattern as below :
http://i.ebayimg.com/00/s/MTUw12323gxNTAw/$(KGr123qF,!p0F123Q~~60_12.JPG?set_id=88123231232F
I need a regex to find and replace the end of the url _12.JPG with _14.JPG. So basically i need to capture the _[numbers only].JPG pattern and replace it with my value.
var regex = new Regex(#"_\d+\.JPG");
var newUrl = regex.Replace(url, "_14.JPG");
_[0-9]+\.JPG\?
works for the sample URL. You didn't really mention whether you wanted the
?set_id=88123231232F gone or not.
Basically, you shouldn't normally be concerned with periods anywhere else in the URL. It is possible, but the additional constraint of the jpg extension should limit anything returned with not much issue.
///_(\d?\d).jpg/ig
var regex = new Regex(#"_(\d?\d).[Jj][Pp][Gg]");
That will capture one or two numbers between an underscore and .jpg
I will double check this, but it should work for both one digit and two digits.

Correction in this simple regular expression

I am new to regular expressions and the one that i have written might be a very simple one but donot know where I am wrong.
#"^([a-zA-Z._]+)#([\d]+)"
This RE is for the following string:
somename#somenumber
Now i am trying to retrieve the somename and somenumber. This is what i did:
ac.name = m.Groups[0].Value;
ac.number = m.Groups[1].Value;
Here ac.name reads the complete string, and ac.number reads somenumber. Where am I wrong in ac.name?
i guess the regex is correct, the problem is, you get the ac.name not from group 1 but group(0), which is the whole string. try this:
ac.name = m.Groups[1].Value;
ac.number = m.Groups[2].Value;
This regex is correct. I think your mistake is in somewhere else. You seem to use C#. So, you should think about the regex usage in the language.
Looking to the code sample in MSDN, you need to use 1-based indexes while accessing Groups instead of zero-based (as also Kent suggested). So, use this:
String name = m.Groups[1].Value;
String number = m.Groups[2].Value;
use this regex (\w+)#(\d+([.,]\d+)?)
Groups[1] will be contain name
Groups[2] will be contain number
I think you should move the + into the capture group:
#"^([a-zA-Z._]+)#([\d]+)"
If this is C#, try without the ^
([a-zA-Z\._]+)#([\d]+)
I just tried it out and it groups properly
Update: escaped the .
If you want only one match (and hence the ^ in original expression), use .Match instead of .Matches method. See MSDN documentation on Regular Expression Classes.

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!

Regex for a string

It would be great if someone could provide me the Regular expression for the following string.
Sample 1: <div>abc</div><br>
Sample 2: <div>abc</div></div></div></div></div><br>
As you can see in the samples provided above, I need to match the string no matter how many number of </div> occurs. If there occurs any other string between </div> and <br>, say like this <div>abc</div></div></div>DEF</div></div><br> OR <div>abc</div></div></div></div></div>DEF<br>, then the Regex should not match.
Thanks in advance.
Try this:
<div>([^<]+)(?:<\/div>)*<br>
As seen on rubular
Notes:
This only works if there are not tags in the abc part (or anything that has a < symbol).
You might want to use start and end of string anchors (^<div>([^<]+)(?:<\/div>)*<br>$ if you want your string to match the pattern exactly.
If you want to allow the abc part to be empty, use * instead of +
That being said, you should be wary of using regex to parse HTML.
In this example, you can use regex because you are parsing a (hopefully) known, regular subset of HTML. But a more robust solution (ie: an [X]HTML parser like HtmlAgilityPack) is preferred when it comes to parsing HTML.
You need to use a real parser. Things like infinitely nested tags can't be handled via regex.
You could also include a named group in the the expression, e.g.:
<div>(?<text>[^<]*)(?:<\/div>)*<br>
Implemented in C#:
var regex = new Regex(#"<div>(?<text>[^<]*)(?:<\/div>)*<br>");
Func<Match, string> getGroupText = m => (m.Success && m.Groups["text"] != null) ? m.Groups["text"].Value : null;
Func<string, string> getText = s => getGroupText(regex.Match(s));
Console.WriteLine(getText("<div>abc</div><br>"));
Console.WriteLine(getText("<div>123</div></div></div></div></div><br>"));
NullUserException's answer is good. Here are a couple of questions, and variations, depending on what you want.
Do you want to prevent anything from occurring before the open div tag? If so, keep the ^ at the beginning of the regex. If not, drop it.
The rest of this post refers to the following section of the regex:
([^<]+?)
Do you want to capture the contents of the div, or just know that it matches your form? To capture, leave it as is. If you don't need to capture, drop the parentheses from the above.
Do you want to match if there is nothing inside the div? If so change the + in the above to *
Finally, although it will work fine, you don't need the ? in the above.
I think, this regex is more flexible:
<div\b[^><]*+>(?>.*?</div>)(?:\s*+</div>)*+\s*+<br(?:\s*+/)?>
I don't include the ^ and $ in the beginning and the end of my regex because we cannot assure that your sample will always in a single line.

Categories

Resources