<
operating system> (IFS or "
File System Driver", "FSD") An
API that allows you to extend
OS/2 to access files stored
on disk in formats other than
FAT and
HPFS, and access
files that are stored on a
network file server.
For example an IFS could provide programs running under OS/2
(including DOS and Windows programs) with access to files
stored under
Unix using the
Berkeley fast file system.
The other variety of IFS (a "remote
file system" or
"redirector") allows
file sharing over a
LAN, e.g. using
Unix's
Network File System protocol. In this case, the
IFS passes a program's
file access requests to a remote
file
server, possibly also translating between different
file
attributes used by OS/2 and the remote
system.
Documentation on the IFS API has been available only by
special request from IBM.
An IFS is structured as an ordinary 16-bit
DLL with entry
points for opening, closing, reading, and writing files, the
swapper,
file locking, and
Universal Naming Convention. The
main part of an IFS that runs in
ring 0 is called by the
OS/2
kernel in the context of the caller's process and
thread. The other part that runs in ring 3 is a utility
library with entry points for FORMAT, RECOVER, SYS, and
CHKDSK.
EDM/2 article (http://edm2.com/0103/).
(1999-04-07)