title: Modify conf file with shell script
body: <p>I have a default conf file that we use over and over again in our projects. And, for each project, the file has to be modified. On more than one occasion, the person editing the conf file made time consuming mistakes.</p>
  
  <p>So, I wanted to write a shell script that can be called to modify the conf file. </p>
  
  <p>But, being new to shell scripts, I don't know how to do this. What is the appropriate *nix tool to open a text file, find a string, replace it with another and then close the text file.</p>
  
  <p>Thanks!
  Eric</p>