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tom
How can I read of a stdio device in linux as root without stealing the device from a session?
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tom
I know how to write to a standard device but not rad
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tom
Read
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tom
It's like the kernel is flapping back and forth
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jonas’
tom, if by stdio you mean tty, you cannot. one of the two readers will win for each byte
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jonas’
learnt that the hard way
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tom
» <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
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tom
Writing oddly works just fine though
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tom
Is does not appear pseudoterminals behave the same way as hardware terminals
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jonas’
they do
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jonas’
I learnt that effect with hardware terminals
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jonas’
ttyS0 or something
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tom
I wonder if that's the same case across other unixes like BSD or solaris
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jonas’
I would be surprised if not
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jonas’
it would be extra work to implement it the way you expect it
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jonas’
a lot of extra work
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jonas’
and extra memory consumption
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jonas’
possibly infinite
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tom
I see
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tom
I understand why
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tom
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
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tom
But realtime monitoring of a terminal session, that's off the table
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jonas’
that’s because X was meant for multiple clients from the beginning
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tom
Architecture wise I understand it
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jonas’
terminals on the other hand were point-to-point
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tom
Xbeing a server with clients