Re: autoconf test ': >emtpy' problem under Ultrix

[Peter Eisentraut]

Akim Demaille writes:

> Peter> The reason (which is documented somewhere in the auto* manuals)
>
> I don't know where.

autoconf.texi

@node Automatic Remaking,  , Build Directories, Makefile Substitutions
@subsection Automatic Remaking

[snip]

The @file{stamp-} files are necessary because the timestamps of
@file{config.h.in} and @file{config.h} will not be changed if remaking
them does not change their contents.  This feature avoids unnecessary
recompilation.  You should include the file @file{stamp-h.in} your
package's distribution, so @code{make} will consider @file{config.h.in}
up to date.  On some old @sc{bsd} systems, @code{touch} or any command
that results in an empty file does not update the timestamps, so use a
command like @code{echo} as a workaround.

> Peter> is that on some (BSD?) systems a 'touch' of an empty file
> Peter> doesn't update the time stamp.  So in a way, yes, you're
> Peter> avoiding empty files, but it is only necessary in 'make'
> Peter> context.
>
> If someone could specify an actual system like this, I'd be happy to
> update autoconf.texi.

-- 
Peter Eisentraut      address@hidden       http://yi.org/peter-e/