Command explanations
install_user=proftpd install_group=proftpd:
Specify the user and group identity for ProFTPD.
--prefix=/usr:
This installs ProFTPD in /usr
instead of /usr/local.
--sysconfdir=/etc:
This prevents the configuration files from going to
/usr/etc.
--localstatedir=/var/run:
This uses /var/run instead of
/usr/var for lock files.