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use warnings;
use Math::MPFR qw(:mpfr);
print "Hello world\n";
{
local(*STDOUT);
open(STDOUT, ">", "output.txt") or die $!; #line 10
$num = Math::MPFR->new(); #$num is a '@NaN@'
Rmpfr_out_str($num, 10, 0, GMP_RNDN);
close STDOUT;
}
print "Goodbye world\n";
Rmpfr_out_str (which wraps the mpfr library's mpfr_out_str function) prints directly to stdout, so I expected that output.txt would contain @NaN@ and the output to the console would look like:
Hello world
Goodbye world
However, output.txt is empty, and the console output looks like:
Hello world
@NaN@Goodbye world
Apparently, redirecting perl's stdout has had no effect on xs's stdout. I guess I would need to redirect stdout from within the XSub.
There's another issue, too, I believe. I think I really want to redirect the output to a variable (which I can return) rather than to a file. But if I replace output.txt with a variable (say, $output) then the script just errors out with No such file or directory at try.pl line 10.
I'm starting to wonder if this approach (interesting though it is) is going to lead to a practical solution.
Wouldn't I be better off requesting (politely, of course) of the mpfr developers that future releases of the mpfr library provide a function that returns the same formatted string as output by mpfr_out_str ?
Cheers,
Rob | [reply]
[d/l]
[select] |
You need to 'redirect' the underlying file descriptor, not point the filehandle STDOUT somewhere else.
Supersearch for responses from tye to STDOUT redirection questions.
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
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