Futurebasic/Language/Reference/lof

Description
If  is the ID number of an open file,   returns the total number of records in the file. If  equals   or   (and the specified device is open),   returns the total number of records currently in the device's input buffer. If there is a "partial" record at the end of the file (or input buffer), it is included in the count.

The returned record count is based on the record length given in, if it's specified. If this parameter is omitted,  uses the record length that was specified in the   statement when the file or the port was opened. If  is omitted and no record length was specified in the   statement, a default record length of 256 is used.

To determine the total number of bytes in the file or in the serial input buffer, use.