FILE_POSITION
Syntax |
where = FILE_POSITION(#channel) |
Location |
DJToolkit 1.16 |
This function will tell you exactly where you are in the file that has been opened, to a directory device, as #channel, if the result returned is negative it is a QDOS error code. If the file has just been opened, the result will be zero, if the file is at the very end, the result will be the same as calling FILE_LENGTH(#channel) - 1, files start at byte zero remember.
EXAMPLE
1500 DEFine FuNction OPEN_APPEND(f$)
1510 LOCal ch, fp
1515 :
1520 REMark Open a file at the end, ready for additional
1530 REMark data to be appended.
1540 REMark Returns the channel number. (Or error)
1545 :
1550 ch = DJ_OPEN(f$)
1560 IF ch < 0 THEN
1570 PRINT "Error: " & ch & " Opening file: " & f$
1580 RETurn ch
1590 END IF
1595 :
1600 MOVE_POSITION #ch, 6e6
1610 fp = FILE_POSITION(#ch)
1620 IF fp < 0 THEN
1630 PRINT "Error: " & fp & " reading file position on: " & f$
1640 CLOSE #ch
1650 RETurn fp
1660 END IF
1665 :
1670 PRINT "File position set to EOF at: " & fp & " on file: " &f$
1680 RETurn ch
1690 END DEFine
CROSS-REFERENCE