OLDMAINZ:orcl:/home/oracle/hru$ cat /etc/shells
/bin/sh
/bin/bash
/sbin/nologin
/bin/dash
/bin/tcsh
/bin/csh
/bin/ksh
OLDMAINZ:orcl:/home/oracle/hru$ grep oracle /etc/passwd
oracle:x:501:502::/home/oracle:/bin/bash
OLDMAINZ:orcl:/home/oracle/hru$ chsh -s /bin/ksh oracle
                                -----------------------
Changing shell for oracle.
Password:
Shell changed.
OLDMAINZ:orcl:/home/oracle/hru$ grep oracle /etc/passwd
oracle:x:501:502::/home/oracle:/bin/ksh