Shell Programming and Scripting

       -P password
              use  password  to  decrypt  encrypted  zipfile entries (if any).
              THIS IS INSECURE!  Many  multi-user  operating  systems  provide
              ways  for  any user to see the current command line of any other
              user; even on stand-alone systems there is always the threat  of
              over-the-shoulder  peeking.   Storing  the plaintext password as
              part of a command line in an automated  script  is  even  worse.
              Whenever  possible,  use  the non-echoing, interactive prompt to
              enter passwords.  (And where security is  truly  important,  use
              strong  encryption  such  as  Pretty Good Privacy instead of the
              relatively weak encryption provided by standard  zipfile  utili-
              ties.)