user6975: This is strange!
The documentation on running the Bitcoin daemon on a Ubuntu machine is clear. The configuration file is supposed to be at $HOME/.bitcoin/ location. And yet, I cannot locate it! I looked for clues at /etc, /var, and /tmp too; nothing there. In fact, in one of my attempts to launch the daemon, the debug.log (created at $HOME/.bitcoin/) did call out the configuration file to be $HOME/.bitcoin/bitcoin.conf but the file itself wouldn't be listed. Permissions? - I don't know.
Can you please tell me where to look for this file?
This is on Ubuntu-16.04, 64-bit where bitcoin was installed via PPA. Yes; I am working with Bitcoin code for the first time.

user37359: The configuration file is definitely in $HOME/.bitcoin/. If you cannot see it, the most likely explanation is that you have not created it. Just use your favorite text editor to do so. As far as I can tell, bitcoind -daemon will run without bitcoin.conf being present and you will still get the message 'Using config file /home/user/.bitcoin/bitcoin.conf' in debug.log even when no file exists.

6975: <p>This is strange!</p>

<p>The <a href="https://bitcoin.org/en/developer-examples#testing-applications" rel="nofollow noreferrer">documentation</a> on running the Bitcoin daemon on a Ubuntu machine is clear. The configuration file is supposed to be at <code>$HOME/.bitcoin/</code> location. And yet, I cannot locate it! I looked for clues at <code>/etc</code>, <code>/var</code>, and <code>/tmp</code> too; nothing there. In fact, in one of my attempts to launch the daemon, the <code>debug.log</code> (created at <code>$HOME/.bitcoin/</code>) did call out the configuration file to be <code>$HOME/.bitcoin/bitcoin.conf</code> but the file itself wouldn't be listed. Permissions? - I don't know.</p>

<p>Can you please tell me where to look for this file?</p>

<p>This is on Ubuntu-16.04, 64-bit where bitcoin was installed via <a href="https://launchpad.net/~bitcoin/+archive/ubuntu/bitcoin/+packages" rel="nofollow noreferrer">PPA</a>. Yes; I am working with Bitcoin code for the first time.</p>
 37359: <p>The configuration file is definitely in <code>$HOME/.bitcoin/</code>. If you cannot see it, the most likely explanation is that you have not created it. Just use your favorite text editor to do so. As far as I can tell, <code>bitcoind -daemon</code> will run without <code>bitcoin.conf</code> being present and you will still get the message 'Using config file /home/user/.bitcoin/bitcoin.conf' in <code>debug.log</code> even when no file exists.</p>
