Re: [PATCH] use test -s to speed up check for empty file

[Eric Blake]

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According to Paolo Bonzini on 10/5/2007 1:56 AM:
> This is the source of run-time performance improvements.  It uses
> "test -s" to know if there will be output from diff, and skips the
> invocation if this is not the case.  I was surprised too by the
> difference, but it's there to see.  I abstracted this into a
> shell function too.
> 
>  
> +at_diff_devnull () {

Namespace, comments...

> +  test -s "$[1]" || return 0

Is 'test -s' portable?  autoconf.texi is silent on the matter.  Would we
need a fallback?  If so, we should calculate it at the same time as we
calculate $at_diff and $at_devnull.

Otherwise, this looks okay.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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