Dlock(2)                  Mar. 8, 1992                   Dlock(2)



NAME
     Dlock - lock or unlock a BIOS disk device

SYNOPSIS
     LONG Dlock( WORD mode, WORD drv );

DESCRIPTION
     Dlock is used to lock or unlock the BIOS device indicated by
     drv.   No  GEMDOS  file operations are permitted on a locked
     drive. Thus, the Dlock call provides a  mechanism  for  disk
     formatters  or  re-organizers  to  lock  out other processes
     while low-level BIOS or XBIOS operations are in progress  on
     the device.

     If mode is 1, the drive is locked; if it is 0 then the drive
     is  unlocked  and may be used again by other programs.  If a
     process terminates while holding a lock  on  a  drive,  that
     drive is automatically unlocked.

     A lock operation followed immediately by an unlock  is  very
     similar  to  a  media change, except that the lock operation
     will fail if there are open files that refer  to  the  indi-
     cated drive.

RETURNS
     0 if the lock/unlock operation was successful

     EACCDN if mode is 1 and either open files exist on the drive
     or  another  process has already locked the drive,or if mode
     is 0 and the drive was locked by a different process

     EDRIVE if drv is not a valid BIOS device number

SEE ALSO
     Fxattr(2)

NOTES
     Note that Dlock operates on  BIOS  devices,  which  may  not
     always  be  in 1-1 correspondence with GEMDOS drive letters.
     For this reason, to lock GEMDOS drive A: (for example),  the
     programmer  should  call  Fxattr on the root directory of A:
     ("A:\") and then use the dev field of the structure returned
     in  order  to determine the BIOS device corresponding to the
     GEMDOS drive.











Version 0.93  Last change: MiNT Programmer's Manual             1