title: decrypt encrypted gpg file using external secret key
body: <p>I encryptd a file using <code>gpg</code>, now I want to decrypt the file.</p>
  
  <p>Is there any way to decrypt the file without need to import the secret file?</p>
  
  <p>We have the secret key in a file called <code>key.sec</code>; can we pass the secret file to <code>gpg</code> as a parameter (when we run the <code>decrypt</code> command from the <code>bash</code> command line) to use when decrypting the encrypted file? Or must we import the secret key then decrypt the encrypted files?</p>