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

[Basin Ilya]

Thank you Sam, that's exactly what I needed.

On 10.04.2018 18:12, Sam Kendall wrote:
> 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 
> <mailto: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> <mailto: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"?
>     >
>     >     _______________________________________________
>     >     Help-make mailing list
>     >    address@hidden <mailto:address@hidden> <mailto:address@hidden 
> <mailto:address@hidden>>
>     >     https://lists.gnu.org/mailman/listinfo/help-make 
> <https://lists.gnu.org/mailman/listinfo/help-make>
>     >
>     >
> 
>     _______________________________________________
>     Help-make mailing list
>     address@hidden <mailto:address@hidden>
>     https://lists.gnu.org/mailman/listinfo/help-make
>