dropuser [options...] [username]
Specifies the host name of the machine on which the server is running. If host begins with a slash, it is used as the directory for the Unix domain socket.
Specifies the Internet TCP/IP port or local Unix domain socket file extension on which the server is listening for connections.
Echo the queries that createdb generates and sends to the server.
Do not display a response.
Prompt for confirmation before actually removing the user.
Specifies the name of the PostgreSQL user to be removed. This name must exist in the PostgreSQL installation. You will be prompted for a name if none is specified on the command line.
The options -h, -p, and -e, are passed on literally to psql. The psql options -U and -W are available as well, but they can be confusing in this context.
dropuser removes an existing PostgreSQL user and the databases which that user owned. Only users with usesuper set in the pg_shadow table can destroy PostgreSQL users.
dropuser is a shell script wrapper around the SQL command DROP USER via the PostgreSQL interactive terminal psql. Thus, there is nothing special about removing users via this or other methods. This means that the psql must be found by the script and that a database server is running at the targeted host. Also, any default settings and environment variables available to psql and the libpq front-end library do apply.