On 26/01/2015 23:52, Olivier Brunel wrote:
> That looks good, except that I need a default value, in case the file
> doesn't exist. If there's a way to work a default value in that case
> then that'd be fine, yes.
> ...is there a way to add a default value if FILE doesn't exist?
I will add a "-D default" option to backtick, for when the subprocess
exits nonzero. I've wanted this feature for some time, but only now
realized that I wanted it. Thanks for helping me clarify my mind. :)
> (re: misconfiguration, in what way though? It could lead to the program
> being triggered for each new line, but that doesn't mean uncontrollably
> spawning children?
Well, some services log a lot. Spawning a process for every new line
can be really, really heavy. (And I don't even want to imagine how heavy
it would be on Solaris.)
I really don't mind forking and execing, as can be proven by execline;
but potentially forking every time a daemon outputs a newline is still
really scary. I need to find the right safety guards before I implement
that.
> It might be a lot, but with a rotation every 4096 bytes one might
> already have frequent calls to the processor, no?)
Sure, with s4096, but who limits their log files to 4k ? It requires
specific configuration to do that; the admin really wanted it to
happen, it's controlled. A daemon's output matching a given regexp
- which could be .* - is a lot less predictable. And if the daemon is
spewing nothing but newlines, you could find yourself forking 4096 times
more than you're already doing with the processor...
--
Laurent
Received on Mon Jan 26 2015 - 23:12:22 UTC