title: How to Read a variable in defined in terminal to a bash script
body: <p><br>
  I am new to shell scripting. I have a very basic question about how we read variables defined in our terminal as input to a shell scirpt. <br></p>
  
  <p>let us say i defined this variable in my terminal <br>
  a=22<br>
  if i do <code>echo $a</code> it gives 22 as output in my terminal.</p>
  
  <p>I wanted to pass this variable as a parameter to a script named input.sh</p>
  
  <pre><code>#!/bin/bash
  
  echo "Enter variable name:"
  read Input
  echo $Input
  </code></pre>
  
  <p>I ran the scirpt as ./input.sh It popped up the message as <br>
  Enter variable name:$a</p>
  
  <p>But in the output i have $a as output not 22. I wanted 22 as output. Is there a way to do this?</p>