Shell Programming Examples

Ping all hosts in a subnet

subnet=”141.93.169
i=1
while [ $i -lt 255 ]       
do
   ping ${subnet}.${i} 2 1>/dev/null 2>&1
   if   [ $? -ne 0 ] ; then
        echo "${subnet}.${i},down"
   else echo "${subnet}.${i},up"
   fi
   i=$(expr $i + 1 )
done

sshhost

#!/bin/bash
#
# ssh-keygen -t dsa -b 8192
#
Host=`echo $0|cut -d / -f5`
echo "Logon  " `date "+%m/%d/%y %H:%M:%S"` $Host >> $HOME/logs/sshhost.log
# Use escape sequence to modify SecureCrt window title: ESC]; text CTRL-G
printf "\033];$Host\007"
Hmcs="hmc100.hmc200"
Vios="uio200.uio299.uio300.uio399"
User=""
[ ! -z $(echo "$Hmcs" | grep "$Host") ] && User="hscroot@"
[ ! -z $(echo "$Vios" | grep "$Host") ] && User="padmin@"
[ ! -z $(echo "$Host" | grep "vio")   ] && User="padmin@"
ssh $User$Host
printf "\033];`uname -n`\007"
echo "Logof  " `date "+%m/%d/%y %H:%M:%S"` $Host >> $HOME/logs/sshhost.log

copypublic.sh

#!/usr/bin/ksh
#
# Copy public key to another system. Target system is $1.
scp -pr $HOME/.ssh/id_dsa.pub $1:/tmp/
ssh $1 <<EOF
mkdir -m 700 .ssh
cat /tmp/id_dsa.pub >>.ssh/authorized_keys
chmod 600 .ssh/authorized_keys
rm /tmp/id_dsa.pub
EOF

postman

How to proces a mail

$ cat .forward
|/home/roggt/receivemail

$ cat receivemail
#!/usr/bin/ksh
echo $(date) >> aaplog
echo "0" $0  >> aaplog
echo "1" $1  >> aaplog
echo $(env)  >> aaplog
echo Extension $EXTENSION >>aaplog
cat     > aapbody
$

mksysb

Create a mksysb and remove older versions. The script runs on the NIM master and an NIM machine resource for the host to be backed up is needed. The mksysb is pulled from the NIM client.

#/usr/bin/ksh
#
# Make mksysb
#
# Arguments Hostname and Suffix
# Pick YYMMDD as suffix.
#
# Run the mksysb and cleanup older versions
#
P=/backups/mksysb/
nim -o define -t mksysb -a server=master -a source=${1} -a mk_image=yes -a mksysb_flags=ev -a location=$P${1}-${2}.mksysb ${1}-${2} >$P${1}-${2}.log 2>$P${1}-${2}.err
if [ $? = 0 ]
then
        echo NIM backup for ${1} completed successfully
        gzip $P${1}-${2}.mksysb &
else
        echo NIM backup for ${1} failed, rc=$?
fi
#
#       Remove older versions
#       Remove NIM resources and corresponding files
Versions=3      # Number of versions to keep on disk
let Arg=$Versions+1
echo Available NIM resources:
lsnim -t mksysb|grep ${1}|sort
for i in $(lsnim -t mksysb|grep ${1}|sort -r|tail -n +$Arg|awk '{print $1}')
do
#       nim -o remove -a rm_image=yes ${i}      # Image renamed by gzip to .gz
        nim -o remove ${i}
        if [ $? = 0 ]
        then
                echo NIM resource ${i} deleted
                echo Available files:
                ls -l $P${1}*
                echo Removing files:
                ls -l $P${i}*
                echo rm    $P${i}*
        else
                echo "Error during remove NIM resource ${i}, rc=$?"
        fi
done