Big Brother plug-ins (3) for monitoring Oracle database availability, tablespace usage and Oracle Dataguard. Straight Perl, no extra Perl modules needed - uses sqlplus for connection. One configuration file for all three plug-ins - easy to add more! Written/tested CentOS 6 against Oracle 10g and 11g databases.
The BB OS user must have the Oracle software owner's environment, at a minimum:
ORACLE_HOME, ORACLE_BASE, LD_LIBRARY_PATH (LIBPATH on some NIX), and, the PATH variable should include: $ORACLE_HOME/bin:.