XMPP Service Operators - 2020-01-07

How can I read of a stdio device in linux as root without stealing the device from a session?

I know how to write to a standard device but not rad

Read

It's like the kernel is flapping back and forth

tom, if by stdio you mean tty, you cannot. one of the two readers will win for each byte

learnt that the hard way

» <jonas’> tom, if by stdio you mean tty, you cannot. one of the two readers will win for each byte yeah, that's what it seems like. Bytes flapping between process one and process 2 despite opening the file in non-exclusive mode

Writing oddly works just fine though

Is does not appear pseudoterminals behave the same way as hardware terminals

they do

I learnt that effect with hardware terminals

ttyS0 or something

I wonder if that's the same case across other unixes like BSD or solaris

I would be surprised if not

it would be extra work to implement it the way you expect it

a lot of extra work

and extra memory consumption

possibly infinite

I see

I understand why

I just think it's odd at a superficial sense that you can very easily attach read-only to a Xsession if you are authorized

But realtime monitoring of a terminal session, that's off the table

that’s because X was meant for multiple clients from the beginning

Architecture wise I understand it

terminals on the other hand were point-to-point

Xbeing a server with clients