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How can I make this regular expression case insensitive?

The regular expression below evaluates email addresses in my RegularExpressionValidator. It is case-sensitive and only allows lowercase. I would like it to allow uppercase as well. I don't even understand how the thing works really, so I don't know where to begin modifying it. How do I make it case-insensitive?

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?

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ddrudik

use RegexOptions.IgnoreCase option.

mrcoulson

ASKER

You may call me a lazy programmer, but this is all handled by a RegularExpressionValidator.

<asp:RegularExpressionValidator ID="vldSenderEmailFormat" runat="server" ControlToValidate="txtSenderEmail" ErrorMessage="Please enter a valid email address in the 'Your Email' field." ValidationExpression="[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?" Display="None" />

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ddrudik

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mrcoulson

ASKER

Lord, I need to read a book on regular expressions. Let me try those!

Jeremy

mrcoulson

ASKER

Both of those evaluate false.

ddrudik

Show me the test string.

mrcoulson

ASKER

Wait a second. It could be that I wasn't paying attention and pasted them into the wrong document. Der.

Jeremy

mrcoulson

ASKER

The first one seems to work. Whew. Could you go the extra mile and explain it a little to me? Regular expressions look like massive sneezings of random characters and I'd like to understand them better.

ddrudik

I can only say that I added A-Z to the pattern in all places that you had a-z to make it case-insensitive.
I cannot say that the pattern actually will validate e-mail addresses (I would submit that validation of any/all e-mail addresses cannot be done with regex alone).

But, for some syntax starters:
[...] is a character set, any characters included within are treated as one set.
* is repeating 0 or more times.
+ is repeating 1 or more times.
. is any character
\ escapes any special characters such as . to make them match literally, such as \. would match "."
\w is a character class for [A-Za-z_]

I have a online regex tester here (PHP PCRE/.NET):
http://www.myregextester.com/

A cheatsheet:
http://regexlib.com/CheatSheet.aspx

Tutorials:
http://www.regular-expressions.info/

ddrudik

mrcoulson, is there anything else I can provide regarding the solution?

mrcoulson

ASKER

No, points are forthcoming. I really appreciate the extra effort with the explanations. I think I seriously need to do some studying in my downtime.

Thanks!

Jeremy

mrcoulson

ASKER

Thanks a ton!

ddrudik

If you are serious about learning more you might consider finding a copy of the definitive reference text on the subject:
http://regex.info/

ddrudik

Thanks for the question and the points.