regex - Cscope insensitive search -

i trying case insentive search in vim cscope. example:

:cs find e regexp 

should find regexp, regexp, regexp , on... how can this? i've been trying (?i) in front of expression, didn't help.

:cs find e expects egrep pattern. since egrep not case-insensitive default there's no reason expect pattern regexp match regexp, regexp, etc.

also, egrep doesn't honor (?i).

to make cscope's search (all search methods, not egrep) case-insensitive default, must add -c flag initialization command:

:cscope add cscope.out -c