mount_msdos



MOUNT_MSDOS(8)          OpenBSD System Manager's Manual         MOUNT_MSDOS(8)


NAME

     mount_msdos - mount an MS-DOS file system


SYNOPSIS

     mount_msdos [-9lsx] [-g gid] [-m mask] [-o options] [-u uid] special node


DESCRIPTION

     The mount_msdos command attaches the MS-DOS file system residing on the
     device special to the global file system namespace at the location
     indicated by node.  This command is invoked by mount(8) when using the
     syntax

         mount [options] -t msdos special node

     The special device must correspond to a partition registered in the
     disklabel(5).

     This command is normally executed by mount(8) at boot time, but can be
     used by any user to mount an MS-DOS file system on any directory that
     they own (provided, of course, that they have appropriate access to the
     device that contains the file system).

     The options are as follows:

     -9      Ignore the special Windows 95/98 directory entries even if
             deleting or renaming a file.  This forces -s.

     -g gid  Set the group of the files in the file system to gid.  The
             default group is the group of the directory on which the file
             system is being mounted.

     -l      Force listing and generation of Windows 95/98 long filenames and
             separate creation/modification/access dates.

             If neither -s nor -l are given, mount_msdos searches the root
             directory of the file system to be mounted for any existing
             Windows 95/98 long filenames.  If no such entries are found, -s
             is the default.  Otherwise -l is assumed.

     -m mask
             Specify the maximum permissions for files and directories in the
             file system.  Only the nine low-order bits of mask are used.

     -o options
             Use the specified mount options, as described in mount(8).

     -s      Force behaviour to ignore and not generate Windows 95/98 long
             filenames.

             If neither -s nor -l are given, mount_msdos searches the root
             directory of the file system to be mounted for any existing
             Windows 95/98 long filenames.  If no such entries are found, -s
             is the default.  Otherwise -l is assumed.

     -u uid  Set the owner of the files in the file system to uid.  The
             default owner is the owner of the directory on which the file
             system is being mounted.

     -x      If a directory is readable, it inherits the x attribute as well.

     File permissions for FAT file systems are imitated, since the file system
     has no real concept of permissions.  The default mask is taken from the
     directory on which the file system is being mounted, except when the -m
     option is used.  FAT does have a ``read only'' mode, in which the
     writable bit is unset.  If such files are found, they are marked non-
     writable; it can be set using chmod -w or unset using chmod +w.

     File modes work the same way for directories.  However if a directory is
     mounted with -x, it will inherit the executable bit if it is readable.
     This can be useful for making files non-executable and directories
     executable: using -x -m 644 will in most cases give permissions of 755
     for directories and 644 for files.  See chmod(1) for more information
     about octal file modes.


SEE ALSO

     chmod(1), mount(2), disklabel(5), fstab(5), disklabel(8), mount(8),
     umount(8)


HISTORY

     The mount_msdos utility first appeared in NetBSD 0.9.  Its predecessor,
     the mount_pcfs utility, appeared in NetBSD 0.8, and was abandoned in
     favor of the more aptly named mount_msdos.


CAVEATS

     The maximum file size supported by the MS-DOS file system is one byte
     less than 4GB.  This is a FAT file system limitation, documented by
     Microsoft in Knowledge Base article 314463.

     The MS-DOS file system (even with long filenames) does not support
     filenames with trailing dots or spaces.  Any such characters will be
     silently removed before the directory entry is written.  This too is a
     FAT file system limitation.

     The use of the -9 flag could result in damaged file systems, albeit the
     damage is in part taken care of by procedures similar to the ones used in
     Windows 95/98.

     The default handling for -s and -l will result in empty file systems
     being populated with short filenames only.  To generate long filenames on
     empty DOS file systems use -l.

     Note that Windows 95/98 handles only access dates, but not access times.

OpenBSD 5.4                    October 14, 2010                    OpenBSD 5.4

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