Permission denied - Line in use

Login as uucp

If you try the following and get these errors, try login as uucp:

$ cu -l /dev/ttyS0
cu: /etc/uucp/port: fopen: Permission denied
$ su -
# cu -l /dev/ttyS0
cu: creat (/var/lock/TMP00000010e9): Permission denied
cu: /dev/ttyS0: Line in use
# su - uucp
$ cu -l /dev/ttyS0
Connected.