perl -we "print tell DATA"
  Name "main::DATA" used only once: possible typo at -e line 1.
  tell() on unopened filehandle DATA at -e line 1.
  -1

perl -we "print tell DATA;__DATA__" -e"aaa" -e "bbb"                    # uh?! no error!
  0

perl -we "print tell DATA;__DATA__" -e"aaa" -e "bbb" -MO=Deparse
  BEGIN { $^W = 1; }
  print tell DATA;
  __DATA__
  -e syntax OK