== The dangerous appeal of the obvious

For reasons that do not fit into the margins of this entry, DWiki
sometimes needs to get the current Unix load average. I developed DWiki
on Linux, and getting the load average on Linux is really easy; you read
a line from _/proc/loadavg_, split it into three floating point numbers,
and you're done. So I wrote a ((get_load)) function that did that and
forgot about the whole thing.

Then [[this server http://gpu.utcc.utoronto.ca/]] got changed from Linux
to FreeBSD, and suddenly that code didn't work any more. (Because I had
been paranoid, it didn't fail explosively; I had assumed that someday
system problems might cause things to fail and coped with it.)

FreeBSD doesn't have a _/proc/loadavg_; instead it has a _getloadavg(3)_
function in the C library. I gloomily contemplated how to make a C
library call from Python, and on the off chance someone had already
written an extension module to do it I did a Google search on [python
getloadavg].

Which promptly turned up the general and supported
Python function to do just this, [[_os.getloadavg()_
http://www.python.org/doc/current/lib/os-path.html]]. This not only
solved my problem but would have saved me the effort of writing
my ((get_load)) function in the first place, if only I had thought
to look for it instead of leaping on the obvious way of getting the
load average on Linux that I already knew about.

This is the dangerous appeal of the obvious: just because I know
how to do something doesn't mean that I know the *best* way to do
something. Maybe I should keep looking slightly harder, just to
make sure.

(You could say my issue with [[rounding DoubleNegationEquivalent]] [[up
../programming/ClearPersonalIdioms]] was the same effect in action,
although it was less obvious to me then.)