Assuming you are using Apache2 and the regular good old LAMP stack.
Use Case Scenario : You have the website located at <code>/var/www/html</code> and have a folder in it called PDFs where there are generated PDFs stored in there. And you want to periodically see which PDFs are located in that folder by going to <a href="https://my-domain.test/PDFs" class="autolinkedURL autolinkedURL-url" target="_blank">my-domain.test/PDFs</a> and have all the PDFs listed on which you can click on a PDF and the browser will either download it or have it viewable in the browser itself.
<pre><code class="lang-bash">cd /var/www/html/PDFs
htpasswd -c .htpasswd sammy
New password: 
Re-type new password: 
Adding password for user sammy
</code></pre>
Now create the .htacess file in PDFs to let it know that it is password protected for directory listing.
<pre><code class="lang-bash">touch .htaccess
vi .htaccess
</code></pre>
<pre><code class="lang-bash">Options +Indexes

&lt;Files *&gt;
AuthType Basic
AuthName "Authentication Required"
AuthUserFile /var/www/html/PDFs/.htpasswd
Require valid-user
</code></pre>
Now, when you goto <a href="https://my-domain.test/PDFs" class="autolinkedURL autolinkedURL-url" target="_blank">my-domain.test/PDFs</a> in the browser, you'll be prompted for a username and password - enter sammy as the username and enter the password that you set before.

Assuming you are using Apache2 and the regular good old LAMP stack.

**Use Case Scenario :** You have the website located at `/var/www/html` and have a folder in it called PDFs where there are generated PDFs stored in there. And you want to periodically see which PDFs are located in that folder by going to https://my-domain.test/PDFs and have all the PDFs listed on which you can click on a PDF and the browser will either download it or have it viewable in the browser itself.

```bash
cd /var/www/html/PDFs
htpasswd -c .htpasswd sammy
New password: 
Re-type new password: 
Adding password for user sammy
```

Now create the .htacess file in PDFs to let it know that it is password protected for directory listing.

```bash
touch .htaccess
vi .htaccess
```

```bash
Options +Indexes

<Files *>
AuthType Basic
AuthName "Authentication Required"
AuthUserFile /var/www/html/PDFs/.htpasswd
Require valid-user
```

Now, when you goto https://my-domain.test/PDFs in the browser, you'll be prompted for a username and password - enter sammy as the username and enter the password that you set before.

Using htpasswd to allow directory listing of files for a particular folder in Apache

General Ubuntu stuff - frankly speaking it's really notes to self
