NAME

pcfs, PCFS − DOS formatted filesystem

DESCRIPTION

PCFS is a filesystem type that allows users direct access to files on DOS formatted disks from within the SunOS operating system.  Once mounted, a PCFS filesystem provides standard SunOS file operations and semantics.  That is, users can create, delete, read and write files on an DOS formatted disk.  They can also create/delete directories and list files in a directory. 

PCFS filesystems are mounted with the command:

mount −F pcfs  device-special directory-name

or, if

/dev/diskette-/pcfspcfs - no -

is in your /etc/vfstab, you can use the following mount command:

mount /pcfs

Files and directories created through PCFS have to comply with the DOS file name convention, which is of the form filename[.ext], where filename consists of from one to eight upper-case characters, while the optional ext consists of from one to three upper-case characters.  PCFS converts all the lower-case characters in a file name to upper-case, and chops off any extra characters in filename or ext. When displaying file names, PCFS only shows them in lower-case. 

One can use either the DOS FORMAT command, or

fdformat −d

command in the SunOS system to format a diskette in DOS format. 

EXAMPLES

If you copy a file

financial.data

from a UNIX filesystem to a PCFS filesystem, it will show up as

FINANCIA.DAT

on the DOS disk. 

The following file names

.login

test.sh.orig

data+

are considered illegal in DOS, therefore can not be created through PCFS. 

SEE ALSO

eject(1), mount(1M), vfstab(4)

NOTES

The following are all the legal characters that are allowed in file names or extensions in PCFS:

0-9, a-z, A-Z, and $#&@!%()-{}<>‘_\^~|’

Since SunOS and DOS operating systems use different character sets, and have different requirements for the text file format, one can use

dos2unix

or

unix2dos

command to convert files between them. 

PCFS offers a convenient transportation vehicle for files between workstations and PC’s.  Since the DOS disk format was designed for use under DOS, it is quite inefficient to operate under the SunOS system.  Therefore, it should not be used as the format for a regular local storage. Use ufs for local storage within the SunOS system. 

WARNINGS

It is not recommended to physically eject an DOS floppy while the device is still mounted as a PCFS filesystem. 

Since PCFS truncates any extra characters in file names and extensions like DOS, be careful when copying files from a UNIX filesystem to a PCFS filesystem.  For instance, the following two files

test.data1 test.data2

in a UNIX filesystem will get copied to the same file

TEST.DAT

in PCFS. 

BUGS

PCFS should handle the disk change condition like DOS, so that the user does not need to unmount the filesystem to change floppies.  Also, PCFS currently cannot be exported as a NFS filesystem. 

Sun Microsystems  —  Last change: 28 July 1992