use IPC::Open3 qw( open3 );

open(local *CHILD_STDIN, '<', 'nul:') or die $!;
_pipe(\local *FROM_CHILD, \local *CHILD_STDOUT);
my $pid = open3('<&CHILD_STDIN', '>&CHILD_STDOUT', '>&STDERR', $cmd);
my $pipe = \*FROM_CHILD;

...

waitpid($pid, 0);