$ db2 -u db2inst1 -w topSecretThe last one - no output at all - is among the most amusing.
DB21002E The parameter for option "-u" specified after the "db2" command or
in the DB2OPTIONS variable is missing or incorrect.
$ db2 -help
DB21001E The option "-h" specified after the "db2" command or in the
DB2OPTIONS variable is missing or incorrect.
$ db2 --help
$
And if you finally do get into the "db2" program and want to leave it: $ db2 ... db2 => exit DB210334E The command was processed as an SQL statement because it was not a valide Comand Line Processor command. During SQL processing it returned: SQL0104N And unexpected token "END-OF-STATEMENT" was found following "exit". Expected tokens may include: "JOIN