Where Online Learning is simpler!

Chapter 5 Linux Shell Scripting

Learn UNIX by examples

$ cat if-args.sh
#!/bin/sh
#	Purpose: To demonstrate the if-elif-else-statement between two integer values.
#	This values of VALUE1 AND VALUE2 are passed from the command line as $1 and $2.
#	Author:  Wahid Lutfy
#	CopyRight © MyWebUnivesity.com
#  Assign the values read from the command line to the variables VALUE1 AND VALUE2.
VALUE1=$1
VALUE2=$2
usage ()
{
echo ""
echo "Usage: $0 $VALUE1 $VALUE2"
echo "Example: if-args.sh 10 5"
echo
exit
}
compare ()
{
#  Find it the smaller value between the two numbers read from command line 
#  Then, display the result of the comparison.
if [ ${VALUE1} -eq  ${VALUE2} ]
then
echo "The value of ${VALUE1} is equal to the value of ${VALUE2}." 
elif [ ${VALUE1} -gt ${VALUE2} ]
then
echo "The value of ${VALUE1} is greater than the value of ${VALUE2}."
else
echo "The value of ${VALUE1} is smaller than the value of ${VALUE2}."
fi
}
#  If the number of arguments $# is smaller than 2, display usage. 
if [ $# -lt 2 ]
then
#  Call the usage function
usage
else
#  Call the compare function
compare
fi

Where Online Learning is simpler!

Chapter 5

Linux Shell Scripting

Type and executate the Linux commands below:

$

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