Computer Dictionary Online

installable file system definition

<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.

(1999-04-07)

installed user base definition

user base

installer definition

<operating system> A utility program to ease the installation of another, probably larger, application. It is also possible for hardware to have an installer accompany it, to install any low level device drivers required.

The installer commonly asks the user to enter desired configuration options for the main program or hardware, and sets up various initialisation files accordingly, as well as copying the main program to a hard disc.

Some badly designed operating systems require applications to provide an uninstaller because of the number of different files modified or created during the installation process.

(1998-02-09)