if(fork()){
                #read
}else{
                my $so_fd=fileno($w_stdout);
                my $se_fd=fileno($w_stderr);
                my $si_fd=fileno($r_stdin);
#
# fd3 must be $w_fd3, so backup current fd3, and reopen 3 to $w_fd3
#
                my $old3=dup(3);
                my $new3=dup2(fileno($w_fd3), 3);
#
# then if any of the other fd's we were going to use was 3, change it 
+to the backup fd
#
                for my $i ($so_fd, $se_fd, $si_fd){
                        if ($i == 3){
                                $i=$old3;
                        }
                }
                open STDOUT, ">&$so_fd";
                open STDERR, ">&$se_fd";
                open STDIN, "<&$si_fd";
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