.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

Regex with exceptions to check incorrect punctuation

Posted By:      Posted Date: October 26, 2010    Points: 0   Category :.NET Framework

Hi to all,

I'm faced with the following problem:

I need to check a punctuation rule in a large amount of text. For this purpose, I want to find all occurances of a word which is NOT preceded by a comma.

The grammatical rule states that the words XYZ, UVW, QRS  must be preceded by a comma, exluding the cases when they are preceded by the words ABC, DEF, GHI, in which cases the comma is not necessary.

1. Lorem ipsum nam ne xyz fuisset efficiantur voluptatibus, albucius molestie neglegentur cu quo. - must be matched because xyz is NOT preceded by a comma
2. Lorem ipsum nam ne, xyz fuisset efficiantur voluptatibus, albucius molestie neglegentur cu quo. - must NOT be matched because xyz is preceded by a comma
3. Lorem ipsum nam ne abc xyz fuisset efficiantur voluptatibus, albucius molestie neglegentur cu quo. - must NOT be matched because xyz is preceded by abc and the comma is omitted correctly
4. Lorem ipsum nam ne, abc xyz fuisset efficiantur voluptatibus, albucius molestie neglegentur cu quo. - must be matched because xyz is preceded by abc but the comma is NOT omitted

Can anyone help me to construct a regex that satisfies the above conditions - with and without lookarounds, if it's possible?

Thank you very much in advance!

View Complete Post

More Related Resource Links

A call to SSPI failed: The target principal name is incorrect - How to ignore this Security Check

I find that I am getting this error since I am using the netTCPBinding. I don't get this exception when the client and server are on the same machine, but when they are on different machines, this exception occurs. If I set the identity on the end point as mentioned in the article: http://blogs.msdn.com/b/drnick/archive/2007/11/08/setting-a-user-principal-on-the-endpoint.aspx it is working fine.   So my question is , should the service end point always have an identity when using netTcpBinging? I tried setting Security.Mode = None and still I got this identity exception. is there any way through which I can ask the service to ignore the SSPI details and accept client request?   Thanks!

regex replace - but with a few exceptions.


I have a string containing HTML and I need to replace some words to be links (I know, working with regex against HTML is not accepted by all developers, but I cannot see an easy solution with any other technique) - I do this with the following code;

string lNewHTML = Regex.Replace(lOldHTML, "(\bword1\b|\bword2|word3\b)", "<a href=\"page.aspx#$1\">$1</a>", RegexOptions.IgnoreCase);

The code works, but I need to include some exceptions to the replace - e.g. I will not replace anything i an img-, li- and a-tag (including link-text and attributes like href and title) but still allow replacements in p-, td- and div-tags.

By using the following code I can avoid replacing in attributes;


But with the above code it still replaces words in e.g. links and headlines which is a no-go.

The last example I have seems to do what I need - but if my HTML-string contains more than a few characters my application crashes;


Can anyone figure out a solution to this?

How to check for space in a password regex having multiple condition

I have a requirment where in the password field should accept all keys except space, it should have atleast one number , length should be 6 to 50
I tried following but did not work
1) Regex = @"^.*(?=.{6,50})(?=.*\d)(?=.*[a-zA-Z]).*$"

2) ^(?=[^\s])(?=[^\s]{6,50})(?=[^\s]*\d)(?=[^\s]*[a-zA-Z]).*$

Following are my test input text ( test case no 2 is having space at end)

ShouldNOT 654321-4
Should NOT654321-5
S houldNOT654321-6
ShouldNOT65432 1-7
S houldNOT 654321-9

Please help.

Thanks in Advance.
Rajendra Dewani

Regards Rajendra Dewani

Using a CompareValidator to check input is a valid date

The CompareValidator can do more than just compare two controls. You can also compare it against several of the main .net data types such as Date, Integer, Double and Currency.

To do this you would set Operator="DataTypeCheck" and instead of setting the ControlToCompare or ValueToCompare attributes as you normally would you use the Type="Date" (or any of the data types I have listed above).

Check All with JQuery and a Asp.Net GridView

Display a Grid on the screen with a checkbox in each row. At the bottom of the page have "Check All" button.

Typically if I need to do anything interesting I use a template column. So my GridView will look like the one below (most other columns removed for readability). The only interesting point to note is the CssClass="ApprovalCheckBox" in the CheckBox ItemTemplate.

How to get more information about the exceptions that can happen in SharePoint 2010 projects?

In case there is an exception anywhere in the SharePoint 2010 project (most common place an exception would happen is during deployment of your SharePoint project, custom deployment configuration or custom deployment steps), there's a registry key EnableDiagnostics available for you to use.

check box control


Hi ,

I have a three check box in my web form ,i need to choose only one check box, if i choose one check box

another 2 check box automatically unchecked

can i use jquery for check box

I thought this would be simple... Trying to create a login does an ajax check before submit


I have the standard .net login control that is working.  (Still learning .net after 15yrs of classic)

What I want to do is OnButtonClick run a javascript function (to do an ajax call to the db to check if login is valid or not) and if it returns true, then submit the form normally, else don't submit. The piece that I can't figure out, is how to correctly override the default click even to hit my JS routine and then submit the form properly afterwards.

Thanks ahead of time

how to check a textbox value in jquery?



I want to perform some action when an asp.net textbox value length is greater than 1 character. And for this I wanted to know how to write this check in jquery?

I have created a check like below-

if ($('[id=txtUserInput]').val().length > 2)
{ do some work...} 

But its giving me the following error

$("[id=txtUserInput]").val() is undefined

Can anybody let me know the right way of doing this?



How to check for null/empty strings on dynamic objects?


What is the proper way to check for null or empty strings on dynamic objects? This is the only solution I've found so far:

if (admin.PasswordHash.GetType() == typeof(DBNull) || admin.PasswordHash == string.Empty)

If the field is null, the object returned is DBNull.Value, but if the field is empty string, it's return as a System.String object. This makes it impossible to do regular "admin.PasswordHash == DBNull.Value" check, as that will fail whenever the field has been set to empty string. Is my example the right (and only) way to go?

Automatically redirect to HTTPS and check if SSL is active



I've set in the web.config:

    <!-- User Authentication -->
    <authentication mode="Forms">
      <forms loginUrl="~/Page/View/Content/Login.aspx" timeout="2880" requireSSL="true" />

This works fine. If there is no ssl connection, the login form doesn't continue. But I would like to check if ssl is active (in codebehind) and, if it's possible, to automatically the user to the https page if he's currently on http. (I could do this job by manually redirect with page.response("https://url.../login.aspx"); but this is not really generic. For example if the webapp is moved to another domain it doesn't work anymore... I'm looking for something like: FormsAuthentication.RedirectWithSSL(); or so... :D)


how to check which pages of my site that my visitor visiting at the moment


 Hi all, and thanks a lot for the replies since now. I have a new question :

I prepared a simple instant messaging system for my web site and i would like to learn which visitor (registered member) is at which page of my site. 

For example : 

Uid:10000, Username:donald, NameSurname:Donald DUCK is a registered and signed in visitor.

I need the code which tells me that visitor is at which page (ie. images.aspx?imageid=143223)

Sorry for my poor english, and let me know if i should explain more clearly :)

Have a good evening...

Regex pattern for validating IPv6


Can anyone can make a regular expression pattern for validating IPv6 (not IPv4)?

Ipv6 has many formats and aliases. I tried making the pattern but written in a lot of codes (i'm not sure my code below will be 100% accepting valid formats and 100% declines invalid formats).


Handling external C++ exceptions


Hi. I'm working in a application that uses an external .Dll developed in C++ language. According the business rule, the .Dll can throws one exception if it found a error. My question is if it's possible handle or catch a exception throwed by the C++ dll? The try/catch doesn't works. Bellow there's the code I'm using to call the C++ dll.

        public extern static IntPtr LoadLibrary(string lpLibFileName);

        [DllImport("kernel32", CharSet = CharSet.Ansi)]
        public extern static IntPtr GetProcAddress(IntPtr hLibModule, string procName);

        public extern static bool FreeLibrary(IntPtr hLibModule);

        private delegate void DllMethodCallBack(string param1, string param2);

        public void CallDllMethod(string param1, string param2)

Tools for memory error check in VS2005


Dear all,

I am going to write vs2005 program with ASP.NET and C++.

As you know that C++ will involve a lot of memory error handling.

Do you know is there any tools for checking memory error in Code Behind C++??

.NET Matters: Aggregating Exceptions


Exceptions in .NET are the fundamental mechanism by which errors and other exceptional conditions are communicated. This month's column provides information about how to aggregate exceptions to help manage a variety of scenarios in which multiple exceptions might result from one operation, including scenarios involving parallelism and concurrency.

Stephen Toub

MSDN Magazine August 2009

CLR Inside Out: Handling Corrupted State Exceptions


There's a danger in using one-size-fits-all exception handling, and you need to know how to avoid it by being as specific as possible about how you handle errors.

Andrew Pardoe

MSDN Magazine February 2009

ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend