use Config;

    if($ENV{PERL_CORE}) {
        if ($Config{'extensions'} !~ /\bIO\b/) {
	    print "1..0 # Skip: IO extension not built\n";
	    exit 0;

use Test::More tests => 11;
use IO::File;
use IO::Seekable;

my $x = IO::File->new_tmpfile();
ok($x, "new_tmpfile");
print $x "ok 2\n";
my $line = <$x>;
is($line, "ok 2\n", "check we can write to the tempfile");

print $x "not ok 3\n";
my $p = $x->getpos;
print $x "ok 3\n";
$line = <$x>;
is($line, "ok 3\n", "test getpos/setpos");

$! = 0;
ok($!, "setpos(undef) makes errno non-zero");

    $Config{d_fsync} || $^O eq 'MSWin32'
        or skip "No fsync", 1;

    ok($x->sync, "sync on a writable handle")
        or diag "sync(): ", $!;

{ # [perl #64772] IO::Handle->sync fails on an O_RDONLY descriptor
       or skip "No fsync", 1;
    $^O =~ /^(?:aix|irix)$/
      and skip "fsync() documented to fail on non-writable handles on $^O", 1;
    $^O eq 'cygwin'
      and skip "fsync() on cygwin uses FlushFileBuffers which requires a writable handle", 1;
    $^O eq 'VMS'
      and skip "fsync() not allowed on a read-only handle on $^O", 1;
    open my $fh, "<", "t/io_xs.t"
       or skip "Cannot open t/io_xs.t read-only: $!", 1;
    ok($fh->sync, "sync to a read only handle")
	or diag "sync(): ", $!;

    # gh 6799
    # This isn't really a Linux/BSD specific test, but /dev/full is (I
    # hope) reasonably well defined on these.  Patches welcome if your platform
    # also supports it (or something like it)
    skip "no /dev/full or not a /dev/full platform", 3
      unless $^O =~ /^(linux|netbsd|freebsd)$/ && -c "/dev/full";
    open my $fh, ">", "/dev/full"
      or skip "Could not open /dev/full: $!", 3;
    $fh->print("a" x 1024);
    ok(!$fh->flush, "should fail to flush");
    ok($fh->error, "stream should be in error");
    ok(!$fh->error, "check clearerr removed the error");
    close $fh; # silently ignore the error

    # [GH #18019] IO::Handle->error misreported an error after successully
    # opening a regular file for reading. It was a regression in GH #6799 fix.
    ok(open(my $fh, '<', __FILE__), "a regular file opened for reading");
    ok(!$fh->error, "no spurious error reported by error()");
    close $fh;