How can I tail dmesg-CodePudding

I am using Ubuntu 20.04.3 LTS. I am trying to monitor the serial port connect with my arduino. I have seen my friend using following command (he performed it in my laptop):

tail -f {dmesg,syslog} | grep -i tty

And whenever I plugin and unplug the arduino, the terminal always keep up showing serial port name, its condition. But when I try it myself, it says that there is not such file or directory. I have search and tried following command:

tail -f var/log/dmesg

tail -f var/log/{dmesg,syslog}

But it seems like it does not show up the serial port or keep up with condition. Would you help me with any ideas?

CodePudding user response：

You can use

dmesg -W | grep -i tty

-w, --follow

Wait for new messages. This feature is supported only on systems with a readable /dev/kmsg (since kernel 3.5.0).

So Output will be something like this

rexter@rexter:/media/rexter/REXDRIVE$ dmesg -w | grep -i tty
[    0.112876] printk: console [tty0] enabled
[  332.500320] Bluetooth: RFCOMM TTY layer initialized

If you want to get only new message and want to hide the old ones then use -W

-W, --follow-new

Wait and print only new messages.

Bonus: Use -T to get the time stamp so that you can get the time when you receive the log.

Thank you :)