Arguments can be given to unFTP either via the command line or via environment variables. To show a list of available program arguments type the following:

unftp --help

To run unFTP with everything set to the defaults:

unftp

This will start unFTP:

• with a filesystem back-end rooted at your OS temporary directory.
• the FTP control channel bound to 0.0.0.0:2121 and the data channel range set to 0.0.0.0 ports 49152..65535
• authentication being anonymous i.e. clients can specify any username and password

Now serving data from your computer's temporary directory is not very useful so lets point it to a different directory by using the --root-dir argument. In addition, lets limit the data port range a bit:

unftp \
  -v \
  --root-dir=/home/unftp/data \
  --bind-address=0.0.0.0:2121 \
  --passive-ports=50000-51000