[systemd-devel] journalctl --since today --follow weirdness

[Colin Guthrie]

Hiya,

A colleague pointed out an oddity in journalctl --since today --follow
output.

It seems the two arguments somewhat contradict each other: one asks for
all the output for today and the other asks for all future messages, but
using them together should obviously behave in a somewhat sensible way!

What I was expecting was basically the same as what journalctl --follow
would produce, but excluding any output not from today. e.g. if the
first 5 lines of a standard journalctl -f happened to be from yesterday,
then I'd expect only the 5 lines from today to be printed and then any
further output as it happens.

What appears to happen instead is that you get the first 10 lines from
the day (i.e. after midnight) and then *all* lines from today following
that after a small delay (likely not a deliberate delay - just whatever
overhead it takes to lookup and output the data), thus taking quite some
time to page through which is definitely not what you expect from
--follow, but arguably what you would expect from --since today. It's
only the delay before full output that makes this very much feel like a
bug rather than intentional (i.e. --since having a higher precedence
than --follow's 10 line limit!)

This is with a recent version of the 208-stable branch.

Can someone confirm is this is still a problem in more recent versions?

Cheers

Col

-- 

Colin Guthrie
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http://colin.guthr.ie/

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