Subject: Re: ksh bugs and behaviour questions
To: <>
From: David Laight <david@l8s.co.uk>
List: tech-userlevel
Date: 01/25/2003 19:23:38
> Hmm.  Or for true slowness, you could use bash:
> 
> $ time sh -c 'for i in $(jot 10000); do /bin/echo -n; done' 
>        11.52 real         0.47 user         5.07 sys
> $ time ksh -c 'for i in $(jot 10000); do /bin/echo -n; done'
>        14.38 real         0.68 user         7.12 sys
> $ time bash -c 'for i in $(jot 10000); do /bin/echo -n; done'
>        22.95 real         1.88 user        12.71 sys
> 
> I was surprised by two things:

I'm surpised there is that much difference!
Trully odd things must be going on in ksh (I don't have bash).

$ time sh -c 'for i in $(jot 10000); do /bin/echo -n; done'
       17.82 real        14.24 user         2.16 sys
$ time sh -c 'for i in $(jot 10000); do echo -n; done'
        0.08 real         0.07 user         0.00 sys
$ time sh -c 'for i in $(jot 10000); do /rescue/echo -n; done'
        5.96 real         4.44 user         0.63 sys
$ time ksh -c 'for i in $(jot 10000); do /bin/echo -n; done'
       29.57 real        20.96 user         7.05 sys
$ time ksh -c 'for i in $(jot 10000); do echo -n; done'
        0.21 real         0.07 user         0.02 sys
$ time ksh -c 'for i in $(jot 10000); do /rescue/echo -n; done'
       16.68 real        11.55 user         4.13 sys

Clearly all the time in the shell is spent once it knows it has to
to an exec....

	David

-- 
David Laight: david@l8s.co.uk