I have a problem opening a USB port /dev/ttyUSB0
.
The device node for this port is:
crw-rw---- 1 root dialout 188, 0 juil. 25 17:18 /dev/ttyUSB0
It seems that there's a problem with groups
command and the group dialout
as:
doom@doom-PC:~$ groups
doom adm cdrom sudo dip plugdev lpadmin sambashare
doom@doom-PC:~$ whoami
doom
doom@doom-PC:~$ groups doom
doom : doom adm dialout cdrom sudo dip plugdev lpadmin sambashare
doom@doom-PC:~$ groups $USER
doom : doom adm dialout cdrom sudo dip plugdev lpadmin sambashare
As I am doom, why doesn't the groups
command show the dialout
group in its output?
And so, why I can't do this:
doom@doom-PC:~$ touch /dev/ttyUSB0
touch: cannot touch '/dev/ttyUSB0': Permission denied
Really think that both are closely related!
This is on Ubuntu 18.04 LTS.
P.S.: If I do newgrp dialout
, it works, but it is not persistent (and not user friendly).