t/23-Monitoring-Livestatus-BigData.t fails on BSD systems (incompatible du)

[eserte]

On my FreeBSD 10.1 smoker I see the following:

#   Failed test 'testfile: /tmp/testresult.json.data written'
#   at t/23-Monitoring-Livestatus-BigData.t line 27.
du: illegal option -- b
usage: du [-Aclnx] [-H | -L | -P] [-g | -h | -k | -m] [-a | -s | -d depth] [-B blocksize] [-I mask] [-t threshold] [file ...]

#   Failed test 'testfile has  bytes'
#   at t/23-Monitoring-Livestatus-BigData.t line 33.
failed to connect - Connection refused at t/23-Monitoring-Livestatus-BigData.t line 52.
# Looks like your test exited with 61 just after 7.
t/23-Monitoring-Livestatus-BigData.t ..............
Dubious, test returned 61 (wstat 15616, 0x3d00)
Failed 9/14 subtests

The du -b option found on Linux systems is not available here, and there does not seem to exist a replacement option.

[sni]

We can just use "-s" to get the size. However later in that test netcat will be used, no idea how portable that is :-)

[eserte]

I think netcat differs even between Linux distributions...