Search for Oracle errors in the last $NUM lines.


NUM=1000
SIGNAL_LIST='^(...-|Error|Starting.*instance)|terminating instance'

tail -$NUM alert_${ORACLE_SID}.log | awk '
BEGIN {prev="" ; ret=1 }
/'"$SIGNAL_LIST"'/ { if ( prev !~ /'"$SIGNAL_LIST"'/ ) { print "" ; print prev;} print $0;ret=0}
{prev=$0}
END { exit ret } '


On Unix Oracle alert log is normally located in bdump/alert_{ORACLE_SID}.log