Reading from a file

for line in $(cat /etc/passwd) do echo $line done

Iterate for a range

for number in {1..10} do echo “Current number is $number” done

Loop for values given

for planet in earth mars saturn jupiter do echo “The planet name is $planet” done

Loop for variable containing multiple values

planets=”earth mars […]

$? => Return code of previous command $0 => Name of the script itself $1-9 => Argument number 1 to 9 given to script ${10} => Argument number 10 given to script $# => Total number of arguments given to script $@ => All arguments given to script but as an individual string values “$*” […]

!/bin/bash CHECK=$0 SERVICE=$1 DATE=`date` OUTPUT=$(ps aux | grep -v grep | grep -v $CHECK |grep $1) echo $OUTPUT if [ “${#OUTPUT}” -gt 0 ] ; then echo “$DATE: $SERVICE service running, everything is fine” else echo “$DATE: $SERVICE is not running” fi

#!/bin/bash ps axho comm| grep $1 > /dev/null result=$? echo “exit code: ${result}” […]

#!/bin/bash # # ***** BEGIN LICENSE BLOCK ***** # Zimbra Collaboration Suite Server # Copyright (C) 2005, 2007, 2008 Zimbra, Inc. # # The contents of this file are subject to the Yahoo! Public License # Version 1.0 (“License”); you may not use this file except in # compliance with the License. You may obtain […]

#!/bin/bash # # apache Start the apache HTTP server. # # The variables below are NOT to be changed. They are there to make the # script more readable. NAME=apache DAEMON=/usr/sbin/$NAME PIDFILE=/var/run/$NAME.pid CONF=/etc/$NAME/httpd.conf APACHECTL=/usr/sbin/${NAME}ctl # note: SSD is required only at startup of the daemon. SSD=`which start-stop-daemon` ENV=”env -i LANG=C PATH=/bin:/usr/bin:/usr/local/bin” SHIB_HOME=/opt/shibboleth-1.3 LD_LIBRARY_PATH=${SHIB_HOME}/libexec:${SHIB_HOME}/lib export LD_LIBRARY_PATH […]