title: Bash script to get its full path (use 'source' to invoke it)
body: <p>In a bash script, is there any method to get the full path of itself?</p>
  
  <pre><code>$ source ~/dev/setup.sh
  </code></pre>
  
  <p>I have tried $_, $-, $0..., but all are irrelevant.</p>
  
  <p>Thanks in advance.</p>