$ perl -Mv5.10 -e'
   open my $o_fh, ">", "a" or die $!;
   open my $i_fh, "<", "a" or die $!;
   unlink "a" or die $!;
   print $o_fh "abc\n" or die $!;
   $o_fh->flush();
   chomp( my $line = <$i_fh> );
   say "<$line>";
'
<abc>