Here&’s a safe backtick or pipe open for read:

           # add error processing as above
           $pid = open(KID_TO_READ, "-|");

           if ($pid) {   # parent
               while (<KID_TO_READ>) {
                   # do something interesting
               }
               close(KID_TO_READ) || warn "kid exited $?";

           } else {      # child
               ($EUID, $EGID) = ($UID, $GID); # suid only
               exec($program, @options, @args)
                   || die "can&’t exec program: $!";
               # NOTREACHED
           }