title: How to use ssh-add to remove identities (pem files) from the agent
body: <p>I can add pem files to my SSH agent very easily using <code>ssh-add</code>, like so:</p>
  
  <pre><code>$ ssh-add /home/jsmith/keys/mytest.pem
  </code></pre>
  
  <p>But I can't seem to remove them:</p>
  
  <pre><code>$ ssh-add -d /home/jsmith/keys/mytest.pem
  Bad key file /home/jsmith/keys/mytest.pem: No such file or directory
  </code></pre>
  
  <p>The pem file still exists though... I haven't moved or changed it in any way.  Why am I having so much trouble removing this pem file from my SSH agent that I just added a moment ago?  What's the correct way to do this?</p>
  
  <p>I want to <strong>avoid</strong> using <code>ssh-add -D</code> (with a capital "D") because that would delete all of the identities from my SSH agent, and I only want to delete the one I've specified.</p>