Installation (In general):
First you need to be sure that you have already installed:
Go to your www directory of your web server and download and extract this software.
tar -xvzf ftp_v2.1.tar.gz
Run the installation wizard install.php in your web browser, you will notes that you must change the permissions of the config.php file.
You could do this as follow, when your web server uses the www user.
chown www config.php
That's all, the rest of the installation procedure will all be done when you follow the installation wizard step by step.
Installation for FreeBSD:
Especially for FreeBSD users there is documentation available that describes how to configure PureFTPd and how to install all those four software requirements.
Links to external documentation:
The web site of the PureFTPd developers.
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