my %bufs;

sub buf_print {
   my $fh = shift @_;
   $bufs{$fh} .= join($,, @_) . $\;
   my $to_write = int( length($bufs{$fh}) / $buf_size ) * $buf_size;
   syswrite($fh, substr($bufs{$fh}, 0, $to_write, '')) if $to_write;
}

sub buf_flush {
   my $fh = shift @_;
   my $to_write = length($bufs{$fh});
   syswrite($fh, substr($bufs{$fh}, 0, $to_write, '')) if $to_write;
}