Edit: /usr/share/doc/pure-ftpd/README.Configuration-File (1124B)
Pure-FTPd strives to remain simple to operate, and keeps the number of
knobs down to a minimum.
Virtually everything can be set using command-line switches, so that a
configuration file is not required.
For example, the '-H' switch is recommended and avoids DNS lookups.
To enable this feature, just add it right after the executable name:
/usr/local/sbin/pure-ftpd -H
Long options are also supported. This is equivalent to the previous
command:
/usr/local/sbin/pure-ftpd --dontresolve
As an alternative to command-line switches, Pure-FTPd can use a
configuration file. The set of supported features is the same no
matter what way of configuring the server is being used.
A sample configuration file named pure-ftpd.conf should have been installed
in /etc/, /usr/local/etc/ or another standard location derived from
the package installation prefix.
Tweak it according to your needs, and start the server using that file:
/usr/local/sbin/pure-ftpd /etc/pure-ftpd.conf
Note the absence of switches. In order to avoid confusion, either a
configuration file or a set of command-line switches can be used.