title: Reading values from file and assigning it to variable in batch script
body: <p>I want to read the file which contains the value of some variables which are used in my batch script. 
  I have created a property file with format</p>
  
  <pre><code>key=key_value
  key=key_value
  </code></pre>
  
  <p>Now, I want to set environment variable's name as key and its value as key_value
  How can I assign?</p>
  
  <p>I have read the file but cannot separate the string "key=key_value" into two strings.
  Thanks in advance.</p>