What is the tilde (~) character doing in regular expressions

[ChristianB]

Hi all!

I know soapUI follows the Java style RexExp constructs, as documented here:
http://www.jdocs.com/javase/7.b12/java/ ... ttern.html
http://support.smartbear.com/viewarticle/55518/

I was looking at the regular expressions used in the Global Sensitive Information Tokens preferences:


I know and understand that the (?s) flag is used, so that whitespace matches include line breaks (DOTALL flag: http://www.jdocs.com/javase/7.b12/java/ ... L#F-DOTALL ), as was explained here: viewtopic.php?t=588

But what I don't understand is why the tilde is included in all of those regexp. It doesn't show up in either soapUI's regex documentation - or Java's.

I'd be grateful for any hints and explanations...

Best regards,

Christian

[PaulDonny]

Somebody please correct me if I am wrong (I am decent with regexp but it's been many years since I used PERL and was able to just run off expressions all day long) but I think it's essentially notifying the system that the regexp expression starts there.

[TSanchez_1]

Hello,

I did some the tilde represents a unary operation that performs logical negation on each bit. I found a stackoverflow link that may be able to help, please see below.

http://stackoverflow.com/questions/1483 ... -does-mean

Regards,
Temil

[ChristianB]

Hi Temil, I'm not sure that's it, as it appears inside the regular expression matcher. If it was in front of it (i.e. outside the delimeters), I think it would act a lot like an exclamation mark (!), turning true (1) into false (0) and vice versa, I guess...

PaulM, I don't think it's a delimiter. If it was, surely it should be on both sides of the matcher, shouldn't it?

[VinayMachamraj]

Hi Christian,

The table show two columns:

1) The token itself can either contain a plain string or a regular expression prefixed with a tilde sign (to separate it from a plain string)
2) A description that will be shown in the Security Log if the corresponding token is found.

For example on Plain String: It would be like this in those two columns,
1) abc@langTag - this not a regular expression.
2) The description to the sting I have give is a string value to a String variable or parameter.

For example on non-plain String : It would be same as the screen shot you have provided with ~ tilde sign means it is not a plain String with value it is regular expression to be followed for that string variable or parameter.

Regards,
Vinay Machamraj

[ChristianB]

Thank you, Vinay, that's extremely useful to know.

How did you find out, if you don't mind me asking?