Monitor Oracle Alert Log

Unix Shell Script To Monitor Oracle Alert Log:

#!/bin/ksh.
/usr/local/bin/RACT.env

export machine=`uname -n`
export script_dir=/export/home/oracle/local/scripts
export bdump=/export/home/oracle/admin/RACT/bdump
export flagfile=/export/home/oracle/admin/RACT/bdump/flag.lis

flagoldval=`cat $flagfile`
cat $bdump/alert_${ORACLE_SID}.log wc -l > $flagfile
flagnewval=`cat $flagfile`
NUM=$(($flagnewval-$flagoldval))

tail -$NUM $bdump/alert_${ORACLE_SID}.log awk
'BEGIN {prev="" ; ret=1 }
/^(...-Error)/ { if ( prev !~ /^(...-Error)/ ) { print "" ; print prev;} print $0;ret=0}
{prev=$0}
END { exit ret } '> $bdump/alert_temp10.log

if [ `cat $bdump/alert_temp10.log wc -l` -gt 0 ]
then
(echo "To: mailto:xxy@test.com/nSubject: CRITICAL: RACT: Error in alert log \n\n"; cat $bdump/alert_temp10.log)/usr/lib/sendmail xxy@test.com
else
echo "No Error"
fi

sed Unix Command

Sed:
-------------
How to use sed, a special editor for modifying files automatically. If you want to write a program to make changes in a file, sed is the tool to use.

There are a few programs that are the real workhorse in the Unix toolbox. These programs are simple to use for simple applications, yet have a rich set of commands for performing complex actions. Don't let the complex potential of a program keep you from making use of the simpler aspects. This chapter, like all of the rest, start with the simple concepts and introduces the advanced topics later on. A note on comments. When I first wrote this, most versions of sed did not allow you to place comments inside the script. Lines starting with the '#' characters are comments. Newer versions of sed may support comments at the end of the line as well.

Find more about sed at:
http://www.grymoire.com/Unix/Sed.html

Find Unix Command

FIND:
--------------
This topic covers the various options of unix command called "FIND". Following are the Table of Contents:
Introduction to find
Problems with other methods
The Simplest Example
"Using find with other commands'
Using xargs with find
Looking for files with particular names
Looking for files by type
Looking for files by sizes
Searching for old files
Searching for files by permission
Owners and groups
Find and commands
Find and Cpio
Using Find to Execute Commands
File comparisons
Expressions
Keeping find from going too far
Fast Find

The below link covers all the above listed table of contents:

http://www.grymoire.com/Unix/Find.html#uh-6

Unix Crontab

1. Crontab Restrictions
You can execute crontab if your name appears in the file /usr/lib/cron/cron.allow. If that file does not exist, you can use crontab if your name does not appear in the file /usr/lib/cron/cron.deny. If only cron.deny exists and is empty, all users can use crontab. If neither file exists, only the root user can use crontab. The allow/deny files consist of one user name per line.

2. Crontab Commands
export EDITOR=vi ;to specify a editor to open crontab file.
crontab -e Edit your crontab file, or create one if it doesn't already exist.
crontab -l Display your crontab file.
crontab -r Remove your crontab file.
crontab -v Display the last time you edited your crontab file. (This option is only available on a few systems.)

3. Crontab file
Crontab syntax :-
A crontab file has five fields for specifying day , date and time followed by the command to be run at that interval.

* * * * * command to be executed
First * indicates: min (0 - 59)
Second * indicates: hour (0 - 23)
Third * indicates: day of month (1 - 31)
Fourth * indicates: month (1 - 12)
Fifth * indicates: day of week (0 - 6) (Sunday=0)

* in the value field above means all legal values as in braces for that column. The value column can have a * or a list of elements separated by commas. An element is either a number in the ranges shown above or two numbers in the range separated by a hyphen (meaning an inclusive range).

Note: The specification of days can be made in two fields: month day and weekday. If both are specified in an entry, they are cumulative meaning both of the entries will get executed .

4. Crontab Example
A line in crontab file like below removes the tmp files from /home/someuser/tmp each day at 6:30 PM.
30 18 * * * rm /home/someuser/tmp/*

5. Crontab Environment
cron invokes the command from the user's HOME directory with the shell, (/usr/bin/sh).
cron supplies a default environment for every shell, defining:
HOME=user's-home-directory
LOGNAME=user's-login-id
PATH=/usr/bin:/usr/sbin:.
SHELL=/usr/bin/sh

Users who desire to have their .profile executed must explicitly do so in the crontab entry or in a script called by the entry.

6. Disable Email
By default cron jobs sends a email to the user account executing the cronjob. If this is not needed put the following command At the end of the cron job line .
>/dev/null 2>&1

7. Generate log file
To collect the cron execution execution log in a file :
30 18 * * * rm /home/someuser/tmp/* > /home/someuser/cronlogs/clean_tmp_dir.log

Basic Unix

This link covers basic Unix Commands to Manage Oracle Database. These commands will help the DBAs to handle Oracle Database running on Unix Servers.
http://www.math.utah.edu/lab/unix/unix-commands.html

Vi Editor Help:
http://www.cs.colostate.edu/helpdocs/vi.html