GENERIC make buildkernel error / fails - posix_fadvise

cliftonr at volcano.org cliftonr at volcano.org
Sun Jan 22 19:43:24 UTC 2012


On 22.01.2012 13:16, Matthew Seaman wrote:
> On 22/01/2012 19:00, cliftonr at volcano.org wrote:
>> If rm had an option to take files from standard input, or if
>> there's another program I'm not aware of which does this, it
>> could serve as the right-hand side of this.
>
> xargs(1) -- generic solution to taking a list of command arguments 
> from
> a file or pipe, and building a command line from them.
...
> xargs(1) is very commonly used in pipelines with find(1).

Thanks for making it clear that my comment was unclear. :-)

I had meant a program which reads the input file list as xargs
does and operates directly on its operands as xargs does

I'm very familiar with xargs, and have used it in many a shell script.
However, it has the weakness that it will end up doing many invocations
on the executable operand, as it batches up the input into command line
arguments.  I don't know to what extent that overhead would compare to 
the
other sources of overhead discussed earlier, or the overhead of 
executing
a Perl interpreter opcode per input, but I'd guess it's higher.

I think I tried that specific comparison of xargs rm vs. perl -nle 
unlink
once, some years ago, for some kind of temp file cleanup, and found the
latter was faster.  I don't have any numbers though, and if I did 
they'd
be long out of date.
   -- Clifton

--
   Clifton Royston  --  cliftonr at iandicomputing.com / 
cliftonr at volcano.org
   Custom programming, network design, systems and network consulting 
services



More information about the freebsd-stable mailing list