INT 21 - DOS 2+ - "LSEEK" - SET CURRENT FILE POSITION
AH = 42h
AL = origin of move
00h start of file
01h current file position
02h end of file
BX = file handle
CX:DX = offset from origin of new file position
Return: CF clear if successful
DX:AX = new file position in bytes from start of file
CF set on error
AX = error code (01h,06h) (see AH=59h)
Notes:  for origins 01h and 02h, the pointer may be positioned before the
start of the file; no error is returned in that case, but subsequent
attempts at I/O will produce errors
if the new position is beyond the current end of file, the file will
be extended by the next write (see AH=40h)
SeeAlso: INT 2F/AX=1228h

See also: 2124

2142 - DOS 2+ - "LSEEK" - SET CURRENT FILE POSITION