sysprog21
Unclear note about term emulator vs virtual console, and journalctl and dmesg
The following note about term emulator vs. console seems to suggest that in a virtual console we always see the output of printk (or pr_info, or others) in the terminal. It doesn't seem to be the case. I always have to check sudo dmesg to find whatever I print from within the module.
Furthermore the note mention journalctl, but that shows the action of insmod and rmmod that I perform, not the output of the printing functions; again, that is shown in dmesg, which is unfortunately used but not presented first, just like journalctl.
I'm still at the beginning (I've read up to chapter 5.6 "Device Drivers"), but I think this is exactly what gives value to my comment.
Should I have better understanding in the future, I'll try to improve this wording myself, if somebody will not have done it yet.
https://github.com/sysprog21/lkmpg/blob/7b38f3713a1eaa5e17d955531d04f535e8b72517/lkmpg.tex#L167-L180
Exactly, they are confusing. A pseudo{terminal,tty}, or PTY is a pair of pseudo-device endpoints which establish asynchronous, bidirectional communication IPC channel (with two ports) between two or more processes. An example using PTY is xterm-pty, which adds a PTY layer to xterm.js. For X11, xterm and rxvt are generally terminal emulators using tty, and current LKMPG does not distinguish from tty and pty though.
