dtcpauth —
    Manipulate POP Authorization DB
  
    dtcpauth | 
    [-d] [--delete]
      user | 
  
  
    dtcpauth | 
    [-l] [--list]
      user | ALL | 
  
  
    dtcpauth | 
    [-u] [--user]
      user [password] | 
  
The dtcpauth allows the super-user or
    master POP user to add, delete, or reset credential data for a user, or list
    which records exist. Only the super-user may initialize the database.
Under normal usage, dtcpauth prompts for a
    new secret, just like the passwd program. It then
    updates the authorization DB.
With the --user or
    -u switch, the super-user or master POP user can
    create or reset credential data for the specified user. This switch allows
    the password to be specified on the command line, which avoids the usual
    prompts and checks. This is mostly useful in a batch environment, such as in
    a script.
With the --init or
    -i switch, the super-user can create a new (or zero
    the existing) authorization DB.
With the --list or
    -l switch, the super-user or master POP user can
    verify the presence of a record for the indicated user, or list users who
    have records. Users can verify the presence of their own records with this
    switch.
With the --delete or
    -d switch, the super-user or master POP user can
    remove a user entry from the authorization DB.
dtcpauth will exit with positive value on
    errors.
  - /usr/local/etc/qpopper/pop.auth
 
  - The APOP authorization database.
 
The dtcpauth command was written by
    Hajimu UMEMOTO ⟨ume@mahoroba.org⟩.
dtcpauth was written in Ruby. :-)