How to Alert by email when errors occur in Log file

This is a nice and simple shell script:

pass the alert log filename to the script below:

cat $1 | grep ORA- > alert.err

if [ 'cat alert.err|wc -l' -gt 0 ]
then
mail -s "$0 $1 Errors" potkin@yourcompany.com < alert.err
fi

The title of the message contains the script being executed ($0), the name of the log being searched ($1), and the lines that matched our initial search (ORA-) as the body of the message.

Based on the principles introduced in this script, a larger one can be written and scheduled to execute at periodic intervals that will search the contents of the alert log (or another file of interest) and send an e-mail if any errors exist. Then the contents of the log can be moved to another file, so that only the most recent error messages will be sent via e-mail.