I didn't get this in before the ticket was closed but thought the following might be useful.

I believe most compilers (if not all) use unit 0 as stderr, but this is not guaranteed by the standard. However, a fortran 2003 compliant compiler provides an intrinsic module 'iso_fortran_env' that contains this information in the constant error_unit. It also provides input_unit (stdin) and output_unit (stdout). So for fortran 2003 (and later) compliant compilers, the portable way to write to stderr is to use the information in this module.

Cheers,

Peter

On Mon, 19 May 2014, Einstein Toolkit wrote:

#1378: provide equivalent of fprintf(stderr, "%s\n", msg) in Fortran --------------------------+------------------------------------------------- Reporter: rhaas | Owner: Type: enhancement | Status: closed Priority: minor | Milestone: Component: Cactus | Version: development version Resolution: wontfix | Keywords: --------------------------+------------------------------------------------- Changes (by rhaas):

• status: new => closed
• resolution: => wontfix

Comment:

Ah, I did not now about unit 0 for stderr. Cactus redirects file descriptor 0 (Unix parlance, stdout) to /dev/null on the non-root processes, so writing to unit 6 (or *) did not work.

-- Ticket URL: https://trac.einsteintoolkit.org/ticket/1378#comment:8 Einstein Toolkit http://einsteintoolkit.org The Einstein Toolkit _______________________________________________ Trac mailing list Trac@einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/trac