2011/10/25 Richard W.M. Jones <rjones(a)redhat.com>:
On Tue, Oct 25, 2011 at 08:33:28PM +0200, Michał Piotrowski wrote:
> 2011/10/25 Chris Adams <cmadams(a)hiwaay.net>:
> > Once upon a time, Michał Piotrowski <mkkp4x4(a)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.
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Best regards,
Michal
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