Peter Jeremy wrote:
On 2008-Nov-05 17:40:11 +0400, rihad <[EMAIL PROTECTED]> wrote:
Imagine this shell pipeline:
sh prog1 | sh prog2
As given above, prog1 blocks if prog2 hasn't yet read previously written
data (actually, newline separated commands) or is busy. What I want is
for prog1 to never block:
sh prog1 | buffer | sh prog2
There's also misc/mbuffer which is supposed to be an enhancement of
misc/buffer - though I haven't used either. I have a program I wrote
to do this but it's not in a releasable state.
That thing only works for certain types of devices (tape?):
$ while :; do echo hi; sleep 1; done | mbuffer -q | cat
warning: Could not stat output device (unsupported by system)!
This can result in incorrect written data when
using multiple volumes. Continue at your own risk!
^C
$
While writing this email I tried another incantation, and buffer finally
worked!
$ while :; do echo hi; sleep 1; done | buffer -s1 -b100 | cat
hi
hi
hi
hi
hi
^C
(each line was output one second apart).
Once again thank to everybody participating!
Wouldn't such an intermediary tool be a great way to boost performance
for certain types of solutions?
I've found that for dump|restore or dump|gzip, I can get quite significant
speedups by adding a buffer that is several hundred MB in the middle.
Well, if OS buffers aren't good enough, then throwing some memory at
disk I/O surely helps ;)
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