How to Assign One Variable to Another in Bash

Nilesh Katuwal Feb 02, 2024
  1. Declare a Variable in Bash
  2. Assign One Variable to Another in Bash
How to Assign One Variable to Another in Bash

In Bash, a variable is created by giving its reference a value. Although the built-in declare statement in Bash is not required to declare a variable directly, it is frequently used for more advanced variable management activities.

To define a variable, all you have to do is give it a name and a value. Your variables should have descriptive names that remind you of their relevance. A variable name cannot contain spaces or begin with a number.

However, it can begin with an underscore. Apart from that, any combination of uppercase and lowercase alphanumeric characters is permitted.

Declare a Variable in Bash

To create a variable in the Bash shell, you must assign a value to that variable.

Syntax:

varname=value

Here, varname is the name of the newly created variable, and value is the value assigned to the variable. A value can be null.

Let’s look at an example.

$ me=superman
$ this_year=2022

Using the echo command, we can see the value of a variable. Whenever you refer to the value of a variable, you must prefix it with the dollar symbol $, as seen below.

$ echo $me

Output:

superman

Let’s put all of our variables to work at the same time.

echo "$me $this_year"

Output:

superman 2022

Assign One Variable to Another in Bash

We can run dest=$source to assign one variable to another. The dest denotes the destination variable, and $source denotes the source variable.

Let’s assign variable a to variable b.

$ a=Ironman
$ b=$a
$ echo "a=$b"

Output:

a=Ironman

Hence, we can easily assign the value of one variable to another using the syntax above.

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