Xref: utzoo comp.unix.internals:2382 comp.unix.sysv386:6148 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!casbah.acns.nwu.edu!nucsrl!igloo!ddsw1!olsa99!zeusa!hendrik From: hendrik@zeusa.UUCP (Hendrik Vermooten) Newsgroups: comp.unix.internals,comp.unix.sysv386 Subject: SCO UNIX *double* device driver Message-ID: <905@zeusa.UUCP> Date: 19 Mar 91 11:28:37 GMT Organization: ZEUS software, Verwoerdburg Lines: 38 SCO Xenix/UNIX, PC type hardware. In short, the problem is the following: I need to "channel" all I/O going to and from a device, through my own handler routine (this routine itself uses hardware to do its job). Examples of this application : Disk Mirroring, Disk Encryption, UNIX disk I/O monitoring, maybe even compression. A picture tells a thousand words: NORMAL DISK ============== ============== INPUT & <---- | MY DEVICE | <------------- | ACTUAL | OUTPUT ----> | & DRIVER | -------------> | DISK DRV | ============== ============== All normal disk I/O must go through MYDRIVER software that uses hardware to do it's job (so must itself be a device driver?) to the STANDARD disk device driver. I don't want to change the disk device driver, because I don't want to have to support all the different types of disks out there! At first this seemed like a perfect application for STREAMS, but I cannot find enough documentation to clearly indicate that what I need to do is possible using STREAMS. ----------------------------------------------------------------------- Jaco Oosthuyzen, ZEUS systems TEL +27 12 64-5507, FAX +27 12 64-8382 Bang: ..!uunet!ddsw1!olsa99!zeusa!jaco or jaco@zeusa.UUCP ----------------------------------------------------------------------- -- -------- Opinions expressed here are my own when not inebriated ---------- Hendrik Vermooten, ZEUS software TEL +27 12 64-5507, FAX +27 12 64-8382 Bang: ..!uunet!ddsw1!olsa99!zeusa!hendrik or hendrik@zeusa.UUCP --- Confucious say: he who use GNU Emacs GNUs he's on to a GNUd thing ----