GREP on words with 2 or more Z's

[Fck_]

Hi !

I need to grep a dictionary file.
Only the words that contain 2 or more z's and only 1 b needs to be listed.

Can't do it :/
Hints?

[Fck_]

Don't think it's possible =D ?

--

Well, I've found this;

cat dutch.txt | grep -i '^[^z]*[z][^z]*[z][^z]*[z][^z]*[^b]*[b]*$'

Don't know is it good .

Found it !


cat dutch.txt | grep -E 'z(.*z)+' | grep 'b'