Re: [PATCH 6/6] use printf as $ECHO

[Ralf Wildenhues]

Hello,

I haven't fully reviewed this patch yet; there are more issues with it.
However:

* Paolo Bonzini wrote on Sat, Nov 08, 2008 at 11:13:32AM CET:
> 
> >>  M4SH_VERBATIM([[
> > 
> > Hmm.  This is a nicer name for m4_echo, for how it is being used; maybe it 
> > is 
> > time to migrated it into the Autoconf manual (perhaps under the name 
> > AS_VERBATIM)?

A bit long, no?

> >> +AC_MSG_CHECKING([for a working printf])
> > 
> > This looks a bit confusing in configure output; would it be better to 
> > state "printf(1)" rather than "printf" (since many people think of 
> > printf(3) 
> > first)?
> 
> I'll leave this to Ralf to judge.

for a working printf command?

> >> +if test "X`printf %s $ECHO`" = "X$ECHO"; then
> >> +  ECHO='printf %s\n'
> > 
> > Just for safety, shouldn't the test use '%s\n' rather than bare %s (in 
> > other 
> > words, make our test match our usage pattern)?
> 
> _AS_ECHO_PREPARE does the same...

Here's a chance to fix both at once.  :-)

> > I may have missed something, but it seems like this patch now requires that 
> > the 
> > $ECHO solution be based on 'printf', even if a shell has a builtin 'echo' 
> > that 
> > fills the job.  Is it worth still checking whether 'echo' fits the bill, in 
> > case it can avoid the forks of lt_func_ECHO?
> 
> The point of this patch series is that apparently Autoconf now thinks
> printf is better than echo.

IIUC then this line of thinking has not yet received exposure to the
real world.  As such, I am quite concerned that this patch will break
some of the older systems.

Esp., I'm quite sure that we need the cat here-document fallback;
but it may not be necessary need to be with a restart.  Sven Mascheck's
pages contained a similar construct in a shell function (there was some
complication, I think an eval, to prevent older shells from expanding
variables too early or so); of course I can't find it there now in a
casual search.  :-/

Also, for Libtool it is pretty important to have a builtin $ECHO; this
thing can be called thousands of times in link mode, unfortunately.

Cheers,
Ralf