EXFAT.UTIL(8)             BSD System Manager's Manual            EXFAT.UTIL(8)

NAME
     exfat.util -- ExFAT file system utility

SYNOPSIS
     exfat.util -p device removable writable
     exfat.util -k device
     exfat.util -s device
     exfat.util -m device directory removable writable nosuid nodev
     exfat.util -u device

DESCRIPTION
     The exfat.util command supports the probing of ExFAT file systems, and
     getting or setting a volume UUID.

     Options:

     -p device removable writable
             Probe the device to determine whether it contains an ExFAT file
             system.  The removable and writable arguments are ignored for
             compatibility with other file system utilities.  If the device
             appears to contain an ExFAT file system, the exit status is 255.
             If the file system contains a label (volume name), that name is
             written to standard output.  If the device does not appear to
             contain an ExFAT file system, the exit status is 254.  An exit
             status of 252 indicates that an I/O error occurred.

     -k device
             Return the volume UUID of the ExFAT file system on device.  If
             the device appears to contain an ExFAT file system, the volume's
             UUID is written to standard output (as formatted by
             uuid_unparse(3)), and the exit status is 253.  If the root direc-
             tory contains a Volume GUID entry, that GUID is the value
             returned; otherwise, the 32-bit volume serial number stored in
             the boot sector is converted to a UUID and returned.  If the
             device does not appear to contain an ExFAT file system, the exit
             status is 254.  An exit status of 252 indicates that an I/O error
             occurred.

             device may be mounted or unmounted.  If it is mounted, the UUID
             is obtained through the file system using the getattrlist(2)
             call.  If the device is not mounted, exfat.util reads from the
             device directly.

     -s device
             Set a new UUID for the ExFAT file system on device, which must
             not be mounted.  This generates a new UUID using uuid_generate(3)
             and stores that UUID in a Volume GUID entry in the root directory
             (creating one if one does not exist, or updating an existing
             entry).  If the UUID is successfully set, the exit status is 253.
             If the device does not appear to contain an ExFAT file system,
             the exit status is 254.  An exit status of 252 indicates that
             device was already mounted, or an I/O error occurred.

     -m device directory removable writable nosuid nodev
             Deprecated.  Mount the ExFAT file system from device onto
             directory.  The removable argument should be either removable if
             the device is removable, or fixed otherwise.  The actual argument
             value is currently ignored.  The writable argument must be either
             readonly or writable which mounts the volume read-only or
             read/write, respectively.  The nosuid argument must be either
             suid or nosuid.  That argument is passed as a mount option.  The
             nodev argument must be either dev or nodev.  That argument is
             passed as a mount option.

     -u device
             Deprecated.  Unmount the file system on device.  If the unmount
             is successful, the exit status is 253.

FILES
     The exfat.util command is installed in the
     /System/Library/Filesystems/exfat.fs/Contents/Resources directory, which
     is typically not in a shell's search path.

COMPATIBILITY
     The -m and -u options are deprecated.  The preferred way to mount an
     ExFAT volume is to let diskarbitrationd(8) mount it automatically when
     the device is discovered, or use the diskutil(8) command to explicitly
     mount a device.  You may also use the mount(8) or mount_exfat(8) commands
     directly.  The preferred way to unmount an ExFAT volume is with the
     diskutil(8) command.  Note that using the umount(8) command usually will
     not work because various process are likely to have open files, which
     will prevent the unmount.  The diskutil(8) command will send a notifica-
     tion that causes many such processes to close their open files so that
     the unmount will succeed.

SEE ALSO
     mount_exfat(8), fsck_exfat(8), diskarbitrationd(8,) diskutil(8), uuid(3,)
     uuid_unparse(3), uuid_generate(3), getattrlist(2)

HISTORY
     The exfat.util utility first appeared in Mac OS X 10.6.3.

BUGS
     The choice of non-zero exit status to indicate success was an unfortunate
     design decision.

     The -u option usually does not work since several processes in Mac OS X
     leave files open on mounted volumes, thus preventing the unmount.  The
     diskutil(8) command is preferred for unmounting.

Darwin                         January 19, 2010                         Darwin