title: Erlang Replacing substring in string
body: <p>I want to replace occurrence substring in the string with some other text in erlang. </p>
  
  <p>Example for the question : I want to replace <em>file_name1</em> with <em>file_name2</em> text.</p>
  
  <p><strong>Input</strong> :
  /user/home/<em>file_name1</em>.txt</p>
  
  <p><strong>Output</strong> :
  /user/home/<em>file_name2</em>.txt</p>
  
  <p>Description with answer appreciated! Thanks :)</p>