BASH - Commands - Command Line Arguments

Getting arguments directly from the command shell can be beneficial in a number of cases.

#!/bin/bash
echo "Total arguments : $#"
echo "First Argument = $1"
echo "Second Argument = $2"

Run this script with two additional parameters after its name.

./test.sh Hello Peter

NOTE: $1 is used for accessing the first argument, $2 for the second, and so on.

The $# is used for getting the total number of arguments.

Getting Arguments with Names

The below example shows how to get command-line arguments with their names.

test.sh

#!/bin/bash
 
for arg in "$@"
do
index=$(echo $arg | cut -f1 -d=)
val=$(echo $arg | cut -f2 -d=)
 
case $index in
X) x=$val;;
Y) y=$val;;
*)
esac
 
done
 
((result=x+y))
 
echo "X+Y=$result"

Run this script with two additional parameters after its name.

./test.sh X=44 Y=100

returns

X+Y=144

NOTE: The arguments here are stored inside ‘$@‘ and the script fetches them using the Linux cut command.