suppress unzip queries

hey i have piece of code working in solaris and same code i want to deploy it in linux but in solaris its not asking for queris but in linux it is !!!!

COMMAND ==>
unzip $test/alter.war -d $webclientHome/.

OUTPUT==>

In solaris it proceeds with following traces

replace /aa/test.txt? [y]es, [n]o, [A]ll, [N]one, [r]ename: NULL
(assuming [N]one)

but in linux it doesn't !!
it WAITS in Linux for user....
replace /aa/test.txt? [y]es, [n]o, [A]ll, [N]one, [r]ename: inflating: /aa/test.txt

Iknow there is -o option to suppress unzip queries but i dont understand without using that -o option how it is working in solaris and not in Linux ?

Presumably, the two unzip commands use different code.

UnZip 5.52 of 28 February 2005, by Info-ZIP. Maintained by C. Spieler. ==> same version is present on solaris and linux machines !!!

Any idea?

The code on either could have been modified. The Linux code you can definitely get; the Solaris version, maybe, maybe not (depending on the version).

as far as i know ,
if we pipe N with command
i.e.

N | unzip $test/alter.war -d $webclientHome/.

It will show u "replace /aa/test.txt? [y]es, [n]o, [A]ll, [N]one, [r]ename: NULL
(assuming [N]one) " and proceed without waiting for user to enter anything (as obvious)

Its not the case in solaris , its just proceeding...!