return a partion of string

[snowingnow]

Hello, I would like to do this:
That says: if incoming string match this pattern: aaaaa~bbbb~ccccc, i would like to get the partion of ccccc, if not return as null, i am new to tcl, thanks in advance..
(a, b, c string length could be different)

 

[Bong]

It's possible that you're asking either of 2 questions. In the first case, you want to match a pattern and grab the 3rd piece of the match. That would be done with regexp as in

regexp {(a*~)(b*~)(c*)} <your string> match var1 var2 var3

The simpler question is how to split a string on "~" and find the 3rd part:

 set var3 [lindex [split <your string> ~] 2]

_________________
Bob Rashkin