C output capture test

IOCaptureTest.t

use strict;
use warnings;

use Test::More;
BEGIN { use_ok('IOCaptureTest') };

use Capture::Tiny qw/:all/;

my $output;

$output = capture {
    IOCaptureTest::c_print_with_fflush();
};

is($output, 'C Output with fflush', 'OK');

$output = capture {
    IOCaptureTest::perl_print();
};

is($output, 'Perl Output', 'OK');

$output = capture {
    IOCaptureTest::c_print();
};

is($output, 'C Output', 'NG');

done_testing();#include "EXTERN.h"

IOCaptureTest.xs

#include "perl.h"
#include "XSUB.h"

#include "ppport.h"


MODULE = IOCaptureTest> >   PACKAGE = IOCaptureTest>>   

void
c_print()
CODE:
{
    printf("C Output");
}

void
perl_print()
CODE:
{
    PerlIO_stdoutf("Perl Output");
}

void
c_print_with_fflush()
CODE:
{
    printf("C Output with fflush");
    fflush( stdout );
}

test

$ perl -Mblib -MIOCaptureTest t/IOCaptureTest.t 
ok 1 - use IOCaptureTest;
ok 2 - OK
ok 3 - OK
not ok 4 - NG
#   Failed test 'NG'
#   at t/IOCaptureTest.t line 39.
#          got: ''
#     expected: 'C Output'
1..4
# Looks like you failed 1 test of 4.
C Output