PERMISSIONS: I want to stress the importance of permissions for "sqlplus".
For any "Other" UNIX user other than the Owner/Group to be able to run sqlplus and access an ORACLE database , read/execute permissions are required (rx) for these 4 directories :
$ORACLE_HOME/bin , $ORACLE_HOME/lib, $ORACLE_HOME/oracore, $ORACLE_HOME/sqlplus
Environment. Set those properly:
A. ORACLE_HOME
(example: ORACLE_HOME=/u01/app/oranpgm/product/12.1.0/PRMNRDEV/
)
B. LD_LIBRARY_PATH
(example: ORACLE_HOME=/u01/app/oranpgm/product/12.1.0/PRMNRDEV/lib
)
C. ORACLE_SID
D. PATH
export PATH="$ORACLE_HOME/bin:$PATH"