The Direct Path to Linux UBUNTU

Chapter 5

UNIX Shell Programming

Execute the shell scripts:

$ 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

Back to Chapter 5 Shell Programming