UsrMove feature (was Re: FESCo meeting minutes for 2011-10-24)

MichaƂ Piotrowski mkkp4x4 at gmail.com
Tue Oct 25 18:39:25 UTC 2011


2011/10/25 Richard W.M. Jones <rjones at redhat.com>:
> On Tue, Oct 25, 2011 at 08:33:28PM +0200, Michał Piotrowski wrote:
>> 2011/10/25 Chris Adams <cmadams at hiwaay.net>:
>> > Once upon a time, Michał Piotrowski <mkkp4x4 at gmail.com> said:
>> >> I created feature page
>> >> https://fedoraproject.org/wiki/Features/F18MorePortableInterpreters
>> >
>> > I strongly object to this "feature".  /bin/sh is a Unix standard back to
>> > IIRC around 7th Edition, and there is NO good reason to break it.  The
>> > "#!/usr/bin/env foo" suggested replacement has always been a hack to
>> > work around broken systems, not something suggested for all scripts.
>>
>> What is wrong with
>> #!/usr/bin/env interpreter
>> from technical POV?
>
> This is what's wrong:
>
>  $ cat > sh.sh
>  #!/bin/sh
>  $ cat > env.sh
>  #!/usr/bin/env sh
>  $ chmod +x sh.sh env.sh
>  $ time for i in $(seq 1000); do ./sh.sh; done
>
>  real            0m2.737s
>  user            0m0.750s
>  sys             0m1.519s
>  $ time for i in $(seq 1000); do ./env.sh; done
>
>  real            0m3.677s
>  user            0m1.013s
>  sys             0m2.296s
>

Yeah, it is noticeably slower - about 0,00094s.


> Rich.
>
> --
> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
> virt-p2v converts physical machines to virtual machines.  Boot with a
> live CD or over the network (PXE) and turn machines into Xen guests.
> http://et.redhat.com/~rjones/virt-p2v
> --
> devel mailing list
> devel at lists.fedoraproject.org
> https://admin.fedoraproject.org/mailman/listinfo/devel



-- 
Best regards,
Michal

http://eventhorizon.pl/


More information about the devel mailing list