PRINT CountLines(COMMAND$)

FUNCTION CountLines (F$)
  IF NOT EXIST(F$) THEN EXIT FUNCTION
  DIM RAW RC = 0 AS ULONG
  DIM RAW C  = 0
  DIM RAW NL = 10
  OPEN F$ FOR BINARY AS FP9
  WHILE NOT EOF(FP9)
    C = GETC(FP9)
    IF C = NL THEN
      INCR RC
    END IF
  WEND
  CLOSE FP9
  FUNCTION = RC
END FUNCTION

Result:

Result not displayed for this example.