Linux Shell Scripts references –

Below sections are listing the scripts with various examples on different situations and work that a linux system administrator has to do, I have written these scripts to automate some common and reoccuring tasks, find below the list of scripts –

SCRIPT 1 : This Script will extract, check environment, do the logging and run the script on Linux server to apply the Quarterly patch provided by Oracle. Below is the reference of a script for applying a oracle weblogic patch –

#########################
#Written by Pankaj Kumar#
#Version 1.0            #
#Dated 03052024         #
#                       #
#                       #
########################
echo "Middleware Patching ----"
echo "Pass argument like sh patchapply.sh p34080315_122140_Generic.zip WLS_SPB_12.2.1.4.240405"
echo "Check JAVA Processes "
echo ""
cdate=$(date +"%d%m%y%H%M")
#cdate=$(date +"%F")
echo ""
plog=patchlogs_$cdate.log
echo ""
MW_HOME=/u01/forms/products/Middleware
JAVA_HOME=/u01/forms/products/jdk1.8.0_333
echo "##########Quarterly Patching######" >> $plog
echo "######Date $cdate ########" >> $plog
dcheckforms=$(df -TH /u01/forms/products | awk '//{print $1, $5 }' | awk '//{print $2 }'|awk 'NR==2 {print $1}' |sed s/'\G*$'//)
if [[ $dcheckforms -ge 15 ]]; then
echo "Enough Space on file system - forms"
df -TH /u01/forms/products
echo "Enough Space on file system - forms" >> $plog
echo ""
echo ""
echo "Proceeding with backups ..."
echo ""  >> $plog
echo "Proceeding with Middleware Backups " >> $plog
echo ""  >> $plog
cp -r $MW_HOME /u01/forms/products/Middleware.bkp.$cdate
cp -r $JAVA_HOME /u01/forms/products/jdk1.8.0_333.bkp.$cdate
echo ""  >> $plog
else
echo "Please increase the disk space on forms"
df -TH /u01/forms/products
echo "Installation is aborted ...."
exit 1
fi
echo ""  >> $plog
. ~/.profile
stopAll
####ENable this check
if pidof -x java > /dev/null
then
    echo "JAVA processes are already running, please stop ALL and proceed again"  >> $plog
    exit 1
fi
echo "creating /tmp/fuser"  >> $plog
touch /tmp/fuser
DOMAIN_HOME=/u01/forms/products/Middleware/user_projects/domains/cs365_domain
##export FORMS_PATH=/APPL/CRE/CRE:/APPL/CRE/CRE_SRC/Common/Lib:/u01/app/oracle/product/12.2.1/forms:/u01/app/oracle/product/12.2.1/user_projects/domains/base_domain/config/fmwconfig/components/FORMS/instances/forms1
##export REPORTS_PATH=/APPL/CRE/CRE:/APPL/CRE/CRE_SRC/Common/Lib:/u01/app/oracle/product/12.2.1/reports:/u01/app/oracle/product/12.2.1/user_projects/domains/base_domain/reports
#export TWO_TASK=ORCL
export TNS_ADMIN=$DOMAIN_HOME/config/fmwconfig/
export TERM=vt220
export ORACLE_TERM=$TERM
##. .profile
# Reports server: Adjust as required to allow forms to get the reports server name
# using "tool_env.getvar('REPORTS_SERVER_NAME', v_rep_server);"
export REPORTS_SERVER_NAME=
export NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P15
export INSTANCE_HOME=$DOMAIN_HOME/config/fmwconfig/components/OHS/instances/ohs1
##. ./.aliases
OPATCH_NO_FUSER=true
export PATH=/tmp:$PATH
patchdir=/tmp
echo ""
echo ""
cd /tmp
echo "Patch Validation check "  >> $plog
echo ""  >> $plog
echo " $1 "  >> $plog
sleep 5
if [ -f "$1" ]; then
    echo "Proceeding to apply  $1 patch .... "  >> $plog
 cd /tmp
## cp /tmp/$1 $patchdir/
## cd $patchdir
echo "OPATCH Update ... "
echo ""  >> $plog
echo "Proceeding with Patch Unzip operation "  >> $plog
echo ""  >> $plog
echo $(PWD)
echo ""
echo "y" | unzip -q $1
echo ""
echo ""
echo "cd into PATCH DIR ....... "
echo ""
echo ""
sleep 15
cd $2/tools/spbat/generic/SPBAT
. ~/.profile
./spbat.sh -phase precheck -oracle_home $ORACLE_HOME
echo ""  >> $plog
echo ""  >> $plog
opatch lsinventory | tail -n 20 >> $plog
./spbat.sh -phase apply -oracle_home $ORACLE_HOME
  echo ""
else
    echo "$1 does not exist." echo ""  >> $plog
fi
echo ""
echo ""
echo "#######################################" >> $plog
echo "Script finished at $cdate " >> $plog
echo "#######################################" >> $plog
echo ""
echo ""

SCRIPT 2 : This script is to check application parameters for webtier installation on Linux system

#!/usr/bin/bash
#RPMS check
filename="$1"
while read -r line
do
        small=`echo $line|awk -F '[:.]' '{print $1}'`
        if [ `rpm -qa|grep $small|wc -l` -lt 1 ];
                then isok='notok'
        else
                isok='ok'
        fi
        echo '\n'
        echo $line "-->" $isok
        echo "--------------------------------------------------------------"
        echo $small
    rpm -qa|grep $small
done < "$filename"
#check SHMMAX
if [ `cat /etc/sysctl.conf|grep SHMMAX|awk -F[:=] '{print $2}'` -gt 4294967295 ]; then
        echo "SHMMAX value is " `cat /etc/sysctl.conf|grep SHMMAX|awk '{print $2}'` " ---> This is OK"
else
        echo "SHMMAX value is " `cat /etc/sysctl.conf|grep SHMMAX|awk '{print $2}'` " ---> WHICH IS NOT OK"
        echo "Change the value of SHMMAX to a value higher than 4294967295 by including the following line in /etc/sysctl.conf:kernel.shmmax = value"
        echo "Activate the new SHMMAX setting by running the command:/sbin/sysctl -p"
        echo "Start the Oracle Universal Installer and install your software"
fi

#Chek /etc/hosts

if [ `cat /etc/hosts|grep 127.0.0.1|wc -l` -lt 1 ] && [ `cat /etc/hosts|grep $iphost|wc -l` -lt 1 ]; then
        echo "Modify the /etc/hosts  file to contain the following entries"
        echo "127.0.0.1      loopback localhost"
        echo "IPADDRESS  HOSTNAME   HOSTNAME.EUROPE.INTRANET"
else
        echo "/etc/hosts entries ---> OK"
fi


# Check  NPTL
if [ `getconf GNU_LIBPTHREAD_VERSION|wc -l` -lt 1 ]; then
        echo "NTPL setup is not proper ------------> NOTOK"
        echo "If you are installing Oracle HTTP Server on a Linux operating system, the operating system needs to set Native POSIX Threads Library (NPTL) as the default threads-implementation."
else
        echo "NTPL setup is ----------> OK"
        echo "----------------------------"
        getconf GNU_LIBPTHREAD_VERSION
fi


#Checking the Open File Limit
cat /etc/passwd|grep fb_| awk -F':'  '{print $1}' >> /tmp/user_list
while read -r line
do
        if [ `cat /etc/security/limits.conf|grep $line|grep soft|grep nofile |awk '{print $4}'` -ne 4096 ] && [ `cat /etc/security/limits.conf|grep $line|grep hard|grep nofile |awk '{print $4}'` -ne 65536 ] && [ `cat /etc/security/limits.d/90-nproc.conf|grep $line|grep soft|grep nproc |awk '{print $4}'` -ne 2047 ] && [ `cat /etc/security/limits.d/90-nproc.conf|grep $line|grep hard|grep nproc |awk '{print $4}'` -ne 16384 ]; then
                echo "Open File Limit are NOTOK"
                echo "As root add the following lines to  /etc/security/limits.conf"
                echo "As root add the following lines to /etc/security/limits.d/90-nproc.conf"
        else
                echo "Open File Limit are OK"
                echo "--------------------------------------------------------------------------"
                cat /etc/security/limits.conf|grep 'hard\|soft'
        fi
done < /tmp/user_list

AWK Reference -
find in a file if userid with 0 exist more then once -
awk -F: '($3 == "0") {print}' /etc/passwd

SCRIPT 3: – Linux Script to check if Answer is Yes or No, Y or N , y or n —