pcfs(7FS) File Systems pcfs(7FS)NAMEpcfs - DOS formatted file system
SYNOPSIS
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/fs/pc_fs.h>
int mount(const char *spec, const char *dir, int mflag, "pcfs",
struct pcfs_args, struct *pc_argp, sizeof(struct pcfs_args));
DESCRIPTIONpcfs is a file system type that enables direct access to files on DOS
formatted disks from within the SunOS operating system.
Once mounted, pcfs provides standard SunOS file operations and seman‐
tics. Using pcfs, you can create, delete, read, and write files on a
DOS formatted disk. You can also create and delete directories and list
files in a directory.
pcfs supports FAT12 (floppies) and FAT16 and FAT32 file systems.
The pcfs file system contained on the block special file identified by
spec is mounted on the directory identified by dir. spec and dir are
pointers to pathnames. mflag specifies the mount options. The MS_DATA
bit in mflag must be set. Mounting a pcfs file system requires a
pointer to a structure containing mount flags and local timezone infor‐
mation, *pc_argp:
struct pcfs_args {
int timezone; /* seconds west of Greenwich */
int daylight; /* type of dst correction */
int flags;
};
The information required in the timezone and daylight members of this
structure is described in ctime(3C). flags can contain the
PCFS_MNT_FOLDCASE flag. Fold names read from the file system to lower‐
case.
Mounting File Systems
Use the following command to mount pcfs from diskette:
mount -Fpcfs device-special directory-name
You can use:
mount directory-name
if the following line is in your /etc/vfstab file:
device-special - directory-namepcfs − no rw
Use the following command to mount pcfs from non-diskette media:
mount -Fpcfs device-special:logical-drive directory-name
You can use:
mount directory-name
if the following line is in your /etc/vfstab file:
device-special:logical_drive − directory-name pcfs − no rw
device-special specifies the special block device file for the diskette
(/dev/disketteN) or the entire hard disk (/dev/dsk/cNtNdNp0 for a SCSI
disk, and /dev/dsk/cNdNp0 for IDE disks) or the PCMCIA pseudo-floppy
memory card (/dev/dsk/cNtNdNsN).
logical-drive specifies either the DOS logical drive letter (c through
z) or a drive number (1 through 24). Drive letter c is equivalent to
drive number 1 and represents the Primary DOS partition on the disk;
drive letters d through z are equivalent to drive numbers 2 through 24,
and represent DOS drives within the Extended DOS partition. Note that
device-special and logical-drive must be separated by a colon.
directory-name specifies the location where the file system is mounted.
For example, to mount the Primary DOS partition from a SCSI hard disk,
use:
mount -Fpcfs /dev/dsk/cNtNdNp0:c /pcfs/c
To mount the first logical drive in the Extended DOS partition from an
IDE hard disk, use:
mount -Fpcfs /dev/dsk/cNdNp0:d /pcfs/d
To mount a DOS diskette in the first floppy drive when Volume Manage‐
ment is not running (see vold(1M)) use:
mount -Fpcfs /dev/diskette /pcfs/a
If Volume Management is running, run volcheck(1) to automatically mount
the floppy and some removable disks.
To mount a PCMCIA pseudo-floppy memory card, with Volume Management not
running (or not managing the PCMCIA media), use:
mount -Fpcfs /dev/dsk/cNtNdNsN /pcfs
Conventions
Files and directories created through pcfs must comply with either the
DOS short file name convention or the long file name convention intro‐
duced with Windows 95. The DOS short file name convention is of the
form filename[.ext], where filename generally consists of from one to
eight upper-case characters, while the optional ext consists of from
one to three upper-case characters.
The long file name convention is much closer to Solaris file names. A
long file name can consist of any characters valid in a short file
name, lowercase letters, non-leading spaces, the characters +,;=[], any
number of periods, and can be up to 255 characters long. Long file
names have an associated short file name for systems that do not sup‐
port long file names (including earlier releases of Solaris). The short
file name is not visible if the system recognizes long file names. pcfs
generates a unique short name automatically when creating a long file
name.
Given a long file name such as This is a really long filename.TXT, the
short file name will generally be of the form THISIS~N.TXT, where N is
a number. The long file name will probably get the short name THI‐
SIS~1.TXT, or THISIS~2.TXT if THISIS~1.TXT already exits (or THI‐
SIS~3.TXT if both exist, and so forth). If you use pcfs file systems on
systems that do not support long file names, you may want to continue
following the short file name conventions. See EXAMPLES.
When creating a file name, pcfs creates a short file name if it fits
the DOS short file name format, otherwise it creates a long file name.
This is because long file names take more directory space. Because the
root directory of a pcfs file system is fixed size, long file names in
the root directory should be avoided if possible.
When displaying file names, pcfs shows them exactly as they are on the
media. This means that short names are displayed as uppercase and long
file names retain their case. Earlier versions of pcfs folded all names
to lowercase, which can be forced with the PCFS_MNT_FOLDCASE mount
option. All file name searches within pcfs, however, are treated as if
they were uppercase, so readme.txt and ReAdMe.TxT refer to the same
file.
To format a diskette or a PCMCIA pseudo-floppy memory card in DOS for‐
mat in the SunOS system, use either the fdformat -d or the DOS FORMAT
command.
Boot Partitions
On x86 systems, hard drives may contain an fdisk partition reserved for
the Solaris boot utilities. These partitions are special instances of
pcfs. You can mount an x86 boot partition with the command:
mount -Fpcfs device-special:boot directory-name
or you can use:
mount directory-name
if the following line is in your /etc/vfstab file:
device-special:boot − directory-name pcfs − no rw
device-special specifies the special block device file for the entire
hard disk (/dev/dsk/cNtNdNp0)
directory-name specifies the location where the file system is mounted.
All files on a boot partition are owned by super-user. Only the super-
user may create, delete, or modify files on a boot partition.
EXAMPLES
Example 1 Sample Displays of File Names
If you copy a file financial.data from a UNIX file system to pcfs, it
displays as financial.data in pcfs, but may show up as FINANC~1.DAT in
systems that do not support long file names.
The following are legal long file names. They are also illegal short
file names:
test.sh.orig
data+
.login
Other systems that do not support long file names may see:
TESTSH~1.ORI
DATA~1
LOGIN~1
The short file name is generated from the initial characters of the
long file name, so differentiate names in the first few characters. For
example, these names:
WorkReport.January.Data
WorkReport.February.Data
WorkReport.March.Data
result in these short names, which are not distinguishable:
WORKRE~1.DAT
WORKRE~2.DAT
WORKRE~13.DAT
These names, however:
January.WorkReport.Data
February.WorkReport.Data
March.WorkReport.Data
result in the more descriptive short names:
JANUAR~1.DAT
FEBRUA~1.DAT
MARCHW~1.DAT
FILES
/usr/lib/fs/pcfs/mount pcfs mount command
/usr/kernel/fs/pcfs 32-bit kernel module
SEE ALSOchgrp(1), chown(1), dos2unix(1), eject(1), fdformat(1), unix2dos(1),
volcheck(1), mount(1M), mount_pcfs(1M), vold(1M), ctime(3C), vfstab(4),
pcmem(7D)WARNINGS
Do not physically eject a DOS floppy while the device is mounted as
pcfs. If Volume Management is managing a device, use the eject(1) com‐
mand before physically removing media.
When mounting pcfs on a hard disk, make sure the first block on that
device contains a valid fdisk partition table.
Because pcfs has no provision for handling owner-IDs or group-IDs on
files, chown(1) or chgrp(1) may generate various errors. This is a lim‐
itation of pcfs, but it should not cause problems other than error mes‐
sages.
NOTES
Only the following characters are allowed in pcfs short file names and
extensions:
0-9
A-Z
$#&@!%()-{}<>`_^~|'
SunOS and DOS use different character sets and have different require‐
ments for the text file format. Use the dos2unix(1) and unix2dos(1)
commands to convert files between them.
pcfs offers a convenient transportation vehicle for files between Sun
workstations and PCs. Because the DOS disk format was designed for use
under DOS, it does not operate efficiently under the SunOS system and
should not be used as the format for a regular local storage. Instead,
use ufs for local storage within the SunOS system.
Although long file names can contain spaces (just as in UNIX file
names), some utilities may be confused by them.
This implementation of pcfs conforms to the behavior exhibited by Win‐
dows 95 version 4.00.950.
BUGSpcfs should handle the disk change condition in the same way that DOS
does, so you do not need to unmount the file system to change floppies.
SunOS 5.10 10 Feb 2009 pcfs(7FS)
