flac dev - Mar 2013 - [PATCH] Change test scripts shell to bash, to avoid lack of arithmetic support in dash, which is sh on Ubuntu 10.04

Erik,

I was thinking of doing this:
export MALLOC_PERTURB_=$(awk 'BEGIN { srand(); print int(rand() * 32767 %
255 + 1) }')

Or would you prefer using 'date'?


On Tue, Mar 19, 2013 at 10:22 PM, Erik de Castro Lopo
<mle+la at mega-nerd.com>wrote:
> Jesse Weinstein wrote:
>
> > The subject line mostly says it all, but for reference, having
#!/bin/sh
> causes the following error:
> >
> > arithmetic expression: expecting primary: " % 255 + 1"
>
> Arithmetic support is actually not the issue, rather its that dash/sh
> doesn't support $RANDOM. The solution to this is to replace $RANDOM
> with $(date +%N) which is obviouslsy not all that random, but which
> is close enough to random for this usage.
>
> Since Jaren is in the process of making the scripts POSIX shell
> compliant, I think swicthing to bash is a bad idea :-).
>
> I was going to do the $RANDOM to $(date +%N) conversion after Jaren's
> POSIX patches were all applied.
>
> Cheers,
> Erik
> --
> ----------------------------------------------------------------------
> Erik de Castro Lopo
> http://www.mega-nerd.com/
> _______________________________________________
> flac-dev mailing list
> flac-dev at xiph.org
> http://lists.xiph.org/mailman/listinfo/flac-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.xiph.org/pipermail/flac-dev/attachments/20130319/03f15ffb/attachment.htm

Which I think srand actually uses 'date' as it's seed in this
case...


On Tue, Mar 19, 2013 at 10:29 PM, Jaren Stangret <sirjaren at gmail.com>
wrote:
> Erik,
>
> I was thinking of doing this:
> export MALLOC_PERTURB_=$(awk 'BEGIN { srand(); print int(rand() * 32767
%
> 255 + 1) }')
>
> Or would you prefer using 'date'?
>
>
> On Tue, Mar 19, 2013 at 10:22 PM, Erik de Castro Lopo <
> mle+la at mega-nerd.com> wrote:
>
>> Jesse Weinstein wrote:
>>
>> > The subject line mostly says it all, but for reference, having
>> #!/bin/sh causes the following error:
>> >
>> > arithmetic expression: expecting primary: " % 255 + 1"
>>
>> Arithmetic support is actually not the issue, rather its that dash/sh
>> doesn't support $RANDOM. The solution to this is to replace $RANDOM
>> with $(date +%N) which is obviouslsy not all that random, but which
>> is close enough to random for this usage.
>>
>> Since Jaren is in the process of making the scripts POSIX shell
>> compliant, I think swicthing to bash is a bad idea :-).
>>
>> I was going to do the $RANDOM to $(date +%N) conversion after
Jaren's
>> POSIX patches were all applied.
>>
>> Cheers,
>> Erik
>> --
>> ----------------------------------------------------------------------
>> Erik de Castro Lopo
>> http://www.mega-nerd.com/
>> _______________________________________________
>> flac-dev mailing list
>> flac-dev at xiph.org
>> http://lists.xiph.org/mailman/listinfo/flac-dev
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.xiph.org/pipermail/flac-dev/attachments/20130319/bf386592/attachment-0001.htm

Jaren Stangret wrote:
> Erik,
> 
> I was thinking of doing this:
> export MALLOC_PERTURB_=$(awk 'BEGIN { srand(); print int(rand() * 32767
%
> 255 + 1) }')
> 
> Or would you prefer using 'date'?
Your's is probably better and this is probably an improvement:

    awk 'BEGIN { srand(); print int(rand() * 255 + 1) }'

Awk's rand seems to be seeded by the current epoch seconds, but in this
case that doesn't matter.

Erik
-- 
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/

>
> Your's is probably better and this is probably an improvement:
>

    awk 'BEGIN { srand(); print int(rand() * 255 + 1)
}'
>

Awk's rand seems to be seeded by the current epoch seconds, but in
this
> case that doesn't matter.

Looks good to me.  I'd even go as far as implementing your nanosecond
approach as the seed for AWK's 'srand()'.  Maybe set up a tiny
function to
use whenever we want a random integer:

random_int () {

awk \

-v nanosecond_seed=$(date +%N) \

'BEGIN {

srand( nanosecond_seed )

print int ( rand() * 255 + 1 )

}'

}

Then we can just call 'random_int' in place of $RANDOM...


On Wed, Mar 20, 2013 at 1:24 AM, Erik de Castro Lopo
<mle+la at mega-nerd.com>wrote:
> Jaren Stangret wrote:
>
> > Erik,
> >
> > I was thinking of doing this:
> > export MALLOC_PERTURB_=$(awk 'BEGIN { srand(); print int(rand() *
32767 %
> > 255 + 1) }')
> >
> > Or would you prefer using 'date'?
>
> Your's is probably better and this is probably an improvement:
>
>     awk 'BEGIN { srand(); print int(rand() * 255 + 1) }'
>
> Awk's rand seems to be seeded by the current epoch seconds, but in this
> case that doesn't matter.
>
> Erik
> --
> ----------------------------------------------------------------------
> Erik de Castro Lopo
> http://www.mega-nerd.com/
> _______________________________________________
> flac-dev mailing list
> flac-dev at xiph.org
> http://lists.xiph.org/mailman/listinfo/flac-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.xiph.org/pipermail/flac-dev/attachments/20130320/69c088bd/attachment-0001.htm