Re: libtool optimization

[Ralf Wildenhues]

Hi Michel, Bob,

* Bob Friesenhahn wrote on Tue, Oct 21, 2008 at 05:26:58PM CEST:
>
> Current libtool still uses the shell that Autoconf chooses for it.  
> However, if you have a faster shell which actually works (e.g. dash) you 
> can specify it via the CONFIG_SHELL environment variable prior to  
> running the configure script.

Actually, you have to specify it twice, unfortunately:
  CONFIG_SHELL=/bin/bash /bin/bash ./configure [OPTIONS...]

As to which shell is best, it's not so clear as it might look at first.
dash and ksh are faster than bash for some packages, but when it comes
to large packages with many objects, the improved appending (var+=val)
implemented in bash >= 3.2 really starts to make a difference, and other
shells will be slower.

Using vendor /bin/sh on, say, some AIX releases, is asking for trouble.
That thing is seriously inefficient, in that for example the Autoconf
testsuite will take days with /bin/sh, but only a couple of hours with
a sane shell.

Cheers,
Ralf