bash$ swrng -dd -fn STDOUT -nb 1200000000 | rngtest
rngtest 2.2
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

rngtest: starting FIPS tests...
rngtest: entropy source exhausted!
rngtest: bits received from input: 9600000000
rngtest: FIPS 140-2 successes: 479575
rngtest: FIPS 140-2 failures: 424
rngtest: FIPS 140-2(2001-10-10) Monobit: 50
rngtest: FIPS 140-2(2001-10-10) Poker: 53
rngtest: FIPS 140-2(2001-10-10) Runs: 164
rngtest: FIPS 140-2(2001-10-10) Long run: 160
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=87.049; avg=88318.678; max=19531250.000)Kibits/s
rngtest: FIPS tests speed: (min=2.034; avg=202.477; max=250.967)Mibits/s
rngtest: Program run time: 151595406 microseconds