Bash Scripting: Variables and Subshell

It is quite easy to declare a variable in Bash shell, take an example like one below:

#! /bin/bash
myname="Kshitiz"
myage="26"
echo "My name is: $myname"
echo "my age is: $myage"

We can also store the output of a valid shell command to a variable, this process is called Subshell.

Here, a valid shell command is sent to the background and its output is then pointed by a variable. Let’s understand that by an example:

#! /bin/bash
currentpath=$(pwd)
currentdate=$(date)

echo $currrentpath
echo $currentdate

The output of the above commands is shown below:

Output of the above commands

We know that a shell runs inside an environment and that environment by default has a bunch or variables pre-defined. To access those variables, we do the ffollowing:

#! /bin/bash
echo "Listing out all the environment variables below:"
env
echo $COMPUTERNAME

The output of above command

This wraps up the utilization of variables and how variables can be used to point to a subshell output.