root@foobar:/etc/postgresql/9.5/main# netstat -tulpen
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       User       Inode       PID/Program name
tcp        0      0 0.0.0.0:5432            0.0.0.0:*               LISTEN      112        44384       25831/postgres
tcp        0      0 0.0.0.0:3451            0.0.0.0:*               LISTEN      0          94839       15010/sshd
tcp6       0      0 :::5432                 :::*                    LISTEN      112        44385       25831/postgres
tcp6       0      0 :::3451                 :::*                    LISTEN      0          94848       15010/sshd

data_directory = '/mnt/whatever'         # use data in another directory
                                         # (change requires restart)
hba_file = '/etc/postgresql/9.5/main/pg_hba.conf'       # host-based authentication file
                                         # (change requires restart)
ident_file = '/etc/postgresql/9.5/main/pg_ident.conf'   # ident configuration file
                                         # (change requires restart)

root@foobar:/# netstat -tulpen
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       User       Inode       PID/Program name
tcp        0      0 0.0.0.0:3451            0.0.0.0:*               LISTEN      0          94839       15010/sshd
tcp6       0      0 :::3451                 :::*                    LISTEN      0          94848       15010/sshd