title: Unix: What is the difference between source and export?
body: <p>I am writing a shell script, to read a file which has key=value pair and set those variables as environment variables. But I have a doubt, if I do <code>source file.txt</code> will that set the variables defined in that file as environment variable or I should read the file line by line and set it using export command ?</p>
  
  <p>Is source command in this case different than export?</p>