I'm curious about the behavior of broadcast messages by
$ sudo wall myfile
the message from myfile
appears on all /dev/ttyN
devices (the ones to which I can switch by pressing Ctrl+Alt+fN), it also appears on the xterm
windows I have opened, but it doesn't appear on gnome-terminal
(actually I use Linux Mint with MATE, so it's mate-terminal
, but it is fork of gnome-terminal
).
There's also interesting note if I run tmux
in the xterm
: I expected that the message would appear on all terminal sessions that are running in tmux
(on all windows, and in each pane of each window), but actually the message appears just at current cursor position in the xterm
window.
If I check current controlling terminal by calling tty
, it reports different terminals for different windows in tmux: say, I have /dev/pts/11
in one tmux window and /dev/pts/12
in another one. But, broadcast message appears just once for each xterm
window, not for each terminal session opened in tmux
.
It seems to me that terminal emulator, when allocating pseudo-terminal, needs, like, "registering" it somewhere to make it able to receive broadcast messages, and so, xterm
does it, but mate-terminal
and tmux
does not. But it sounds weird since pseudo-terminal is allocated by the kernel, so, it should be "registered" automatically everywhere it needs to be.
I'd be glad if someone explain how does it work and why the behavior is that (seemingly weird).
gnome-terminal
, but not withurxvt
.mesg
?mesg "is y"
both ongnome-terminal
andurxvt
here.