title: Opening New Programs using Commands in Mac OS X Terminal
body: <p>I want to open programs in Terminal by writing a single command, like what is already done for Java complilation:</p>
  
  <p><code>javac HelloWorld.java</code></p>
  
  <p>For any program I install, that functionality isn't available. For example, to open SWI-Prolog I have to type </p>
  
  <p><code>/opt/local/bin/swipl</code></p>
  
  <p>when I want to type just</p>
  
  <p><code>swipl</code></p>
  
  <p>which results in a <code>-bash: swipl: command not found</code>. How do I create this new command?</p>