mtools - utilities to access DOS disks in Unix.
Introduction
Mtools is a public domain collection of tools to allow
Unix systems to manipulate MS-DOS files: read, write, and
move around files on an MS-DOS filesystem (typically a
floppy disk). Where reasonable, each program attempts to
emulate the MS-DOS equivalent command. However, unneces
sary restrictions and oddities of DOS are not emulated.
For instance, it is possible to move subdirectories from
one subdirectory to another.
Mtools is sufficient to give access to MS-DOS filesystems.
For instance, commands such as mdir a: work on the a:
floppy without any preliminary mounting or initialization
(assuming the default `/etc/mtools.conf' works on your
machine). With mtools, one can change floppies too with
out unmounting and mounting.
Where to get mtools
Mtools can be found at the following places (and their
mirrors):
http://mtools.linux.lu/mtools-3.9.8.tar.gz
ftp://www.tux.org/pub/knaff/mtools/mtools-3.9.8.tar.gz
ftp://ibiblio.unc.edu/pub/Linux/utils/disk-management/mtools-3.9.8.tar.gz
Before reporting a bug, make sure that it has not yet been
fixed in the Alpha patches which can be found at:
http://mtools.linux.lu/
ftp://www.tux.org/pub/knaff/mtools
These patches are named mtools-version-ddmm.taz, where
version stands for the base version, dd for the day and mm
for the month. Due to a lack of space, I usually leave
only the most recent patch.
There is an mtools mailing list at mtools @ tux.org .
Please send all bug reports to this list. You may sub
scribe to the list by sending a message with 'subscribe
mtools @ tux.org' in its body to majordomo @ tux.org .
(N.B. Please remove the spaces around the "@" both times.
I left them there in order to fool spambots.) Announce
ments of new mtools versions will also be sent to the
mailing list is archived at http://www.tux.org/hyper
mail/mtools/latest
Common features of all mtools commands
Options and filenames
MS-DOS filenames are composed of a drive letter followed
by a colon, a subdirectory, and a filename. Only the file
name part is mandatory, the drive letter and the subdirec
tory are optional. Filenames without a drive letter refer
to Unix files. Subdirectory names can use either the '/'
or '\' separator. The use of the '\' separator or wild
cards requires the names to be enclosed in quotes to pro
tect them from the shell. However, wildcards in Unix file
names should not be enclosed in quotes, because here we
want the shell to expand them.
The regular expression "pattern matching" routines follow
the Unix-style rules. For example, `*' matches all MS-DOS
files in lieu of `*.*'. The archive, hidden, read-only
and system attribute bits are ignored during pattern
matching.
All options use the - (minus) as their first character,
not / as you'd expect in MS-DOS.
Most mtools commands allow multiple filename parameters,
which doesn't follow MS-DOS conventions, but which is more
user-friendly.
Most mtools commands allow options that instruct them how
to handle file name clashes. See section name clashes, for
more details on these. All commands accept the -V flags
which prints the version, and most accept the -v flag,
which switches on verbose mode. In verbose mode, these
commands print out the name of the MS-DOS files upon which
they act, unless stated otherwise. See section Commands,
for a description of the options which are specific to
each command.
Drive letters
The meaning of the drive letters depends on the target
architectures. However, on most target architectures,
drive A is the first floppy drive, drive B is the second
floppy drive (if available), drive J is a Jaz drive (if
available), and drive Z is a Zip drive (if available). On
those systems where the device name is derived from the
SCSI id, the Jaz drive is assumed to be at Scsi target 4,
and the Zip at Scsi target 5 (factory default settings).
On Linux, both drives are assumed to be the second drive
on the Scsi bus (/dev/sdb). The default settings can be
changes using a configuration file (see section
Current working directory
The mcd command (`mcd') is used to establish the device
and the current working directory (relative to the MS-DOS
filesystem), otherwise the default is assumed to be A:/.
However, unlike MS-DOS, there is only one working direc
tory for all drives, and not one per drive.
VFAT-style long file names
This version of mtools supports VFAT style long filenames.
If a Unix filename is too long to fit in a short DOS name,
it is stored as a VFAT long name, and a companion short
name is generated. This short name is what you see when
you examine the disk with a pre-7.0 version of DOS.
The following table shows some examples of short names:
Long name MS-DOS name Reason for the change
--------- ---------- ---------------------
thisisatest THISIS~1 filename too long
alain.knaff ALAIN~1.KNA extension too long
prn.txt PRN~1.TXT PRN is a device name
.abc ABC~1 null filename
hot+cold HOT_CO~1 illegal character
As you see, the following transformations happen to
derive a short name:
* Illegal characters are replaced by underscores. The
illegal characters are ;+=[]',\"*\\<>/?:|.
* Extra dots, which cannot be interpreted as a main
name/extension separator are removed
* A ~n number is generated,
* The name is shortened so as to fit in the 8+3 limi
tation
The initial Unix-style file name (whether long or short)
is also called the primary name, and the derived short
name is also called the secondary name.
Example:
mcopy /etc/motd a:Reallylongname
Mtools creates a VFAT entry for Reallylongname, and uses
REALLYLO as a short name. Reallylongname is the primary
mcopy /etc/motd a:motd
Motd fits into the DOS filename limits. Mtools doesn't
need to derivate another name. Motd is the primary name,
and there is no secondary name.
In a nutshell: The primary name is the long name, if one
exists, or the short name if there is no long name.
Although VFAT is much more flexible than FAT, there are
still names that are not acceptable, even in VFAT. There
are still some illegal characters left (\"*\\<>/?:|), and
device names are still reserved.
Unix name Long name Reason for the change
--------- ---------- ---------------------
prn prn-1 PRN is a device name
ab:c ab_c-1 illegal character
As you see, the following transformations happen if a
long name is illegal:
* Illegal characters are replaces by underscores,
* A -n number is generated,
Name clashes
When writing a file to disk, its long name or short name
may collide with an already existing file or directory.
This may happen for all commands which create new direc
tory entries, such as mcopy, mmd, mren, mmove. When a name
clash happens, mtools asks you what it should do. It
offers several choices:
overwrite
Overwrites the existing file. It is not possible to
overwrite a directory with a file.
rename
Renames the newly created file. Mtools prompts for
the new filename
autorename
Renames the newly created file. Mtools chooses a
name by itself, without prompting
skip Gives up on this file, and moves on to the next (if
any)
the prompt. If you use a lower case letter, the action
only applies for this file only, if you use an upper case
letter, the action applies to all files, and you won't be
prompted again.
You may also chose actions (for all files) on the command
line, when invoking mtools:
-D o Overwrites primary names by default.
-D O Overwrites secondary names by default.
-D r Renames primary name by default.
-D R Renames secondary name by default.
-D a Autorenames primary name by default.
-D A Autorenames secondary name by default.
-D s Skip primary name by default.
-D S Skip secondary name by default.
-D m Ask user what to do with primary name.
-D M Ask user what to do with secondary name.
Note that for command line switches lower/upper differen
tiates between primary/secondary name whereas for interac
tive choices, lower/upper differentiates between just-
this-time/always.
The primary name is the name as displayed in Windows 95 or
Windows NT: i.e. the long name if it exists, and the short
name otherwise. The secondary name is the "hidden" name,
i.e. the short name if a long name exists.
By default, the user is prompted if the primary name
clashes, and the secondary name is autorenamed.
If a name clash occurs in a Unix directory, mtools only
asks whether to overwrite the file, or to skip it.
Case sensitivity of the VFAT filesystem
The VFAT filesystem is able to remember the case of the
filenames. However, filenames which differ only in case
are not allowed to coexist in the same directory. For
example if you store a file called LongFileName on a VFAT
filesystem, mdir shows this file as LongFileName, and not
as Longfilename. However, if you then try to add LongFile
name to the same directory, it is refused, because case is
The VFAT filesystem allows to store the case of a filename
in the attribute byte, if all letters of the filename are
the same case, and if all letters of the extension are the
same case too. Mtools uses this information when display
ing the files, and also to generate the Unix filename when
mcopying to a Unix directory. This may have unexpected
results when applied to files written using an pre-7.0
version of DOS: Indeed, the old style filenames map to all
upper case. This is different from the behavior of the old
version of mtools which used to generate lower case Unix
filenames.
high capacity formats
Mtools supports a number of formats which allow to store
more data on disk as usual. Due to different operating
system abilities, these formats are not supported on all
OS'es. Mtools recognizes these formats transparently where
supported.
In order to format these disks, you need to use an operat
ing system specific tool. For Linux, suitable floppy tools
can be found in the fdutils package at the following loca
tions~:
ftp://www.tux.org/pub/knaff/fdutils/.
ftp://ibiblio.unc.edu/pub/Linux/utils/disk-management/fdutils-*
See the manpages included in that package for further
detail: Use superformat to format all formats except XDF,
and use xdfcopy to format XDF.
More sectors
The oldest method of fitting more data on a disk is to use
more sectors and more cylinders. Although the standard
format uses 80 cylinders and 18 sectors (on a 3 1/2 high
density disk), it is possible to use up to 83 cylinders
(on most drives) and up to 21 sectors. This method allows
to store up to 1743K on a 3 1/2 HD disk. However, 21 sec
tor disks are twice as slow as the standard 18 sector
disks because the sectors are packed so close together
that we need to interleave them. This problem doesn't
exist for 20 sector formats.
These formats are supported by numerous DOS shareware
utilities such as fdformat and vgacopy. In his infinite
hybris, Bill Gate$ believed that he invented this, and
called it `DMF disks', or `Windows formatted disks'. But
in reality, it has already existed years before! Mtools
Unix PC.
Bigger sectors
By using bigger sectors it is possible to go beyond the
capacity which can be obtained by the standard 512-byte
sectors. This is because of the sector header. The sector
header has the same size, regardless of how many data
bytes are in the sector. Thus, we save some space by using
fewer, but bigger sectors. For example, 1 sector of 4K
only takes up header space once, whereas 8 sectors of 512
bytes have also 8 headers, for the same amount of useful
data.
This method allows to store up to 1992K on a 3 1/2 HD
disk.
Mtools supports these formats only on Linux.
2m
The 2m format was originally invented by Ciriaco Garcia de
Celis. It also uses bigger sectors than usual in order to
fit more data on the disk. However, it uses the standard
format (18 sectors of 512 bytes each) on the first cylin
der, in order to make these disks easyer to handle by DOS.
Indeed this method allows to have a standard sized boot
sector, which contains a description of how the rest of
the disk should be read.
However, the drawback of this is that the first cylinder
can hold less data than the others. Unfortunately, DOS can
only handle disks where each track contains the same
amount of data. Thus 2m hides the fact that the first
track contains less data by using a shadow FAT. (Usually,
DOS stores the FAT in two identical copies, for additional
safety. XDF stores only one copy, and it tells DOS that
it stores two. Thus the same that would be taken up by the
second FAT copy is saved.) This also means that your
should never use a 2m disk to store anything else than a
DOS fs.
Mtools supports these format only on Linux.
XDF
XDF is a high capacity format used by OS/2. It can hold
1840 K per disk. That's lower than the best 2m formats,
but its main advantage is that it is fast: 600 millisec
onds per track. That's faster than the 21 sector format,
and almost as fast as the standard 18 sector format. In
order to access these disks, make sure mtools has been
compiled with XDF support, and set the use_xdf variable
piling mtools, and `misc variables', for details on how to
do this. Fast XDF access is only available for Linux ker
nels which are more recent than 1.1.34.
Mtools supports this format only on Linux.
Caution / Attention distributors: If mtools is compiled on
a Linux kernel more recent than 1.3.34, it won't run on an
older kernel. However, if it has been compiled on an older
kernel, it still runs on a newer kernel, except that XDF
access is slower. It is recommended that distribution
authors only include mtools binaries compiled on kernels
older than 1.3.34 until 2.0 comes out. When 2.0 will be
out, mtools binaries compiled on newer kernels may (and
should) be distributed. Mtools binaries compiled on ker
nels older than 1.3.34 won't run on any 2.1 kernel or
later.
Exit codes
All the Mtools commands return 0 on success, 1 on utter
failure, or 2 on partial failure. All the Mtools commands
perform a few sanity checks before going ahead, to make
sure that the disk is indeed an MS-DOS disk (as opposed
to, say an ext2 or minix disk). These checks may reject
partially corrupted disks, which might otherwise still be
readable. To avoid these checks, set the MTOOLS_SKIP_CHECK
environmental variable or the corresponding configuration
file variable (see section global variables)
Bugs
An unfortunate side effect of not guessing the proper
device (when multiple disk capacities are supported) is an
occasional error message from the device driver. These
can be safely ignored.
The fat checking code chokes on 1.72 Mb disks mformatted
with pre-2.0.7 mtools. Set the environmental variable
MTOOLS_FAT_COMPATIBILITY (or the corresponding configura
tion file variable, `global variables') to bypass the fat
checking.
See also
floppyd_installtest mattrib mbadblocks mcd mcopy mdel
mdeltree mdir mdu mformat minfo mkmanifest mlabel mmd
mmount mmove mrd mren mtoolstest mtype
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