> I believe that
> 1) Its too much trouble parsing the output everytime.

i don't buy that.  that takes very little code.  since you
have evidently already written the code, the cost
is zero.

(if you're worried about runtime, i measure parsing
time at 338ns on a core i7 920.  cf. attached digestspd.c)

> 2) Calling some function from an included library will be faster.

maybe.  are you sure that it matters?  i measure
base fork/exec latency on a 1.8ghz xeon5000 at 330µs.
(files served from the fileserver, not a ram disk.)
the attached fork.c and nop.c were used to do the
measurement.  i measure vac throughput at ~3mb/s
for small files from a brand new venti running from a
ramdisk.  the venti was tiny with 5mb isect and 100mb
arenas, and empty.  at that rate, 330µs will cost you
1038 bytes, or 0.3%.

remember that dynamic linking isn't free.  that cost
assumes that dynamic linking is free, and it is not.

- erik