printf STDERR "before: fileno(STDOUT)=%d\n", fileno(STDOUT);

open $old_stdout, ">&STDOUT" or die "open: $!";
close( STDOUT );

pipe( $smash_stdout, STDOUT );

printf STDERR "after:  fileno(STDOUT)=%d\n", fileno(STDOUT);

##</code><code>##

before: fileno(STDOUT)=1
after:  fileno(STDOUT)=6

##</code><code>##

printf STDERR "before: fileno(STDOUT)=%d\n", fileno(STDOUT);

open $old_stdout, ">&STDOUT" or die "open: $!";
# _don't_ explicitly close STDOUT here

local(*RH, *WH);
pipe RH, WH;
open STDOUT, ">&WH" or die "open: $!";

printf STDERR "after:  fileno(STDOUT)=%d\n", fileno(STDOUT);

##</code><code>##

before: fileno(STDOUT)=1
after:  fileno(STDOUT)=1

##</code><code>##

open $old_stdout, ">&STDOUT" or die "open: $!";
local(*RH, *WH);
pipe RH, WH;
open STDOUT, ">&WH" or die "open: $!";

# write something to the pipe
print "foo";
# and have some fork/exec'ed process write to the pipe (via stdout)
system('echo bar');

close WH;
my $out = <RH>;

print STDERR "got from pipe: $out";   # $out is "foobar\n"