for $foo ('a'..'c') {
    open FH,'|-', 'cat -';
    select FH;
    for $bar (1..rand 10) { write }
    $- = 0;
    close FH;
}
format FH_TOP = 
=@=
$foo
.
format FH =
 @
$bar
.
__END__
=a=
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