[ 2.468149] 0000:00:03.3:
ttyS4 at I/O 0xec98 (irq = 17) is a
16550A
[ 13.514432] usb 7-2: FTDI USB Serial Device converter now
attached to
ttyUSB0
This shows that there are 3 serial ports available: ttyS0, ttyS4 and ttyUSB0 (a USB adaptor)
♦
Checking port permissions
Using the ports found above, execute the following command
♦
ls -l /dev/tty{S0, S4, USB0}↵
The permissions, given below, show that a user has to be root or a member of the dialout
group to be able to access these devices
crw-rw---- 1 root dialout 4, 64 Oct 31 06:44 /dev/ttyS0
crw-rw---- 1 root dialout 4, 68 Oct 31 06:45 /dev/ttyS4
crw-rw---- 1 root dialout 188, 0 Oct 31 07:58 /dev/ttyUSB0
♦
2.
Checking group membership
groups↵
The output will be similar to the following:
adm cdrom sudo dip plugdev users lpadmin sambashare
Notice that dialout is not in the list
♦
A user can be added to the dialout group with the following command
♦
sudo adduser $USER dialout↵
Group membership will not take effect until the next logon.
♦
3.
Linux
30
