use strict ; use warnings ;

  *SUE = \127 ;

  my $a = *SUE ;
  my $b = \*SUE ;

  printf "sex(\$a) = %10s and \${\*{\$a}{SCALAR}} = %d\n", sex($a), ${*{$a}{SCALAR}} ;
  printf "sex(\$b) = %10s and \${\*{\$b}{SCALAR}} = %d\n", sex($b), ${*{$b}{SCALAR}} ;

  sub sex {
    my ($thing) = @_ ;
    my $sex = ref($thing) ;
    return $sex ? "ref:$sex" : ref(\$thing) ;
  } ;

##</code><code>##

  sex($a) =       GLOB and ${*{$a}{SCALAR}} = 127
  sex($b) =   ref:GLOB and ${*{$b}{SCALAR}} = 127

##</code><code>##

  use strict ; use warnings ;

  use IO::Handle ;
  use FileHandle ;
  use Scalar::Util qw(reftype) ;

  print "1________________________________\n",
        'open FH, ">&2" ;', "\n" ;
         open FH, ">&2" ;
    show('*FH', *FH) ;
    show('\*FH', \*FH) ;
    show('*FH{IO}', *FH{IO}) ;

  print "\n",
        "2________________________________\n",
        'open my $OUT, ">&2" ; ', "\n" ;
         open my $OUT, ">&2" ;
    show('$OUT', $OUT) ;
    show('*$OUT{IO}', *$OUT{IO}) ;

  print "\n",
        "3________________________________\n",
        'my $ih = new IO::Handle ;', "\n" ;
         my $ih = new IO::Handle ;
  print 'reftype($ih) = ', reftype($ih), "\n" ;
  print 'open $ih, ">&2" ;', "\n" ;
         open $ih, ">&2" ;
    show('$ih', $ih) ;
    show('*$ih{IO}', *$ih{IO}) ;

  print "\n",
        "4________________________________\n",
        'my $fh = new FileHandle ;', "\n" ;
         my $fh = new FileHandle ;
  print 'reftype($fh) = ', reftype($fh), "\n" ;
  print 'open $fh, ">&2" ;', "\n" ;
         open $fh, ">&2" ;
    show('$fh', $fh) ;
    show('*$fh{IO}', *$fh{IO}) ;

  sub show {
    my ($tag, $FH) = @_ ;

    my $can = $FH->can('autoflush') ? "can 'autoflush'" : "can NOT 'autoflush'" ;
    my $tst = defined(-t $FH) ? "OK" : 'undef' ;

    printf $FH "  show%-12s => %-18s fileno=%d  test=%-5s  %s\n",
               "($tag)", sex($FH), fileno($FH), $tst, $can ;
  } ;

  sub sex {
    my ($thing) = @_ ;
    my $sex = ref($thing) ;
    return $sex ? "ref:$sex" : ref(\$thing) ;
  } ;

##</code><code>##

  1________________________________
  open FH, ">&2" ;
    show(*FH)        => GLOB               fileno=4  test=OK     can NOT 'autoflush'
    show(\*FH)       => ref:GLOB           fileno=4  test=OK     can NOT 'autoflush'
    show(*FH{IO})    => ref:FileHandle     fileno=4  test=undef  can 'autoflush'

  2________________________________
  open my $OUT, ">&2" ;
    show($OUT)       => ref:GLOB           fileno=5  test=OK     can NOT 'autoflush'
    show(*$OUT{IO})  => ref:FileHandle     fileno=5  test=undef  can 'autoflush'

  3________________________________
  my $ih = new IO::Handle ;
  reftype($ih) = GLOB
  open $ih, ">&2" ;
    show($ih)        => ref:IO::Handle     fileno=6  test=OK     can 'autoflush'
    show(*$ih{IO})   => ref:FileHandle     fileno=6  test=undef  can 'autoflush'

  4________________________________
  my $fh = new FileHandle ;
  reftype($fh) = GLOB
  open $fh, ">&2" ;
    show($fh)        => ref:FileHandle     fileno=7  test=OK     can 'autoflush'
    show(*$fh{IO})   => ref:FileHandle     fileno=7  test=undef  can 'autoflush'

##</code><code>##

  open my $FH, ..... ;

##</code><code>##

  use IO::Handle ;
  open my $FH = new IO::Handle, .... ;

##</code><code>##

  $STDERR  = \*STDERR ;
  my $DATA = \*DATA ;

##</code><code>##

  $STDERR  = bless \*STDERR, 'IO::Handle' ;
  my $DATA = bless \*DATA,   'IO::Handle' ;

##</code><code>##

  no strict ;

  announce(STDERR, "Hello World\n") ;

  sub announce {
    my $FH = shift ;
    print $FH @_ ;
  } ;