Re: Original stdout inside the $(shell ...) function

[Sam Kendall]

Basin,

This should do what you want:

SQLFILES := $(info finding SQLFILES...)$(shell cd "$(srcdir)" && find .
-name "*.sql")

Sam Kendall

On Tue, Apr 10, 2018 at 11:08 AM Basin Ilya <address@hidden> wrote:

> Hi David.
> I'll try to explain what I want better. The evaluation should print a
> diagnostic message and it should be printed to a file descriptor that was
> the stdout of the make program when it was started. That is, when you run
> the make command with output redirected to /dev/null, the diagnostic
> message should be suppressed as well, because it's not an error or warning:
>
>     $ make >/dev/null
>     $
>
>     $ make
>     blah blah
>     finding SQLFILES...
>     blah blah
>     ...
>     $
>
>
> Currently my message is printed to stderr and therefore always printed:
>
>     $ make >/dev/null
>     finding SQLFILES...
>     $
>
> The problem is with make, not with the shell programming. Here's an
> equivalent of my current variable assignment, rewritten for shell:
>
>     SQLFILES=`>&2 echo finding SQLFILES... && cd "${srcdir}" && find .
> -name "*.sql"`
>
> And this is how my problem would be solved, if it was shell:
>
>     exec 4>&1
>     SQLFILES=`>&4 echo finding SQLFILES... && cd "${srcdir}" && find .
> -name "*.sql"`
>
> The message is printed to the fd "4", which is the original stdout, while
> everything else is printed to fd "1", which is the stdout redirected by the
> parent shell to perform the assignment.
>
> Unfortunately, I can't find anything like "exec 4>&1" (globally) in Make.
> The only workaround I can think of is calling make from a wrapper, which
> performs the redirection.
>
>
> On 10.04.2018 17:25, David Boyce wrote:
> > This looks like a basic shell programming issue, not a make problem at
> all. Try pulling this logic out of make and running it directly in the
> shell; if it behaves correctly there but not when plugged back into make,
> then you'll have a make question. This looks more like a scoping problem.
> Here is (effectively) your original script:
> >
> > % sh -c ">&2 echo finding SQLFILES... && date" 1>1 2>2
> >
> > % head 1 2
> > ==> 1 <==
> > Tue Apr 10 07:18:56 PDT 2018
> >
> > ==> 2 <==
> > finding SQLFILES...
> >
> > And here's a variant with different scoping:
> >
> > % sh -c "(echo finding SQLFILES... && date) 1>&2" 1>1 2>2
> >
> > % head 1 2
> > ==> 1 <==
> >
> > ==> 2 <==
> > finding SQLFILES...
> > Tue Apr 10 07:19:09 PDT 2018
> >
> > It's not clear to me exactly what you want but this should illustrate
> that the issue is shell redirection.
> >
> > Personally I prefer techniques that let the shell handle verbosity
> instead of typing ad-hoc messages:
> >
> > SQLFILES := $(shell set -x; cd "$(srcdir)" && find . -name "*.sql")
> >
> > David
> >
> > On Tue, Apr 10, 2018 at 3:07 AM, Basin Ilya <address@hidden
> <mailto:address@hidden>> wrote:
> >
> >     Hi. I want to print a diagnostic message whenever my shell
> expression is evaluated. Currently, I have the following line in my
> makefile:
> >
> >         SQLFILES := $(shell >&2 echo finding SQLFILES... && cd
> "$(srcdir)" && find . -name "*.sql")
> >
> >     As you can see, the message "finding SQLFILES..." is printed to
> stderr, but I want the original stdout instead. Does GNU Make make it
> available as some other fd, say, "4"?
> >
> >     _______________________________________________
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> >
> >
>
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