6500stom@hub.UUCP (12/24/89)
What do the bits in VCBAtrb field mean? IV-177 sez that: 0-4 something about inconsistencies 6 set if volume is busy 7 set if volume is locked by hardware 15 set if volume is looked by software When I checked out my HDs and floppy I found that bit 6 was always set and bit 5 was set only on my HDs. Bit 9 was set only on my floppy. The reason I want to know this stuff is because I'm trying to write a substitute for SFDialog and I need to know if I can eject a volume. Does anyone know how to detect when a volume is mounted or dismounted without watching disk insert events or scanning the volume indexes? Does anyone know where SFDialog gets the volume's SICNs? How do you know if your talking to a floppy or an HD? Is it a good idea to use the mod date to see if a volume has changed? If Finder checks the mod date why doesn't it do it more often? Thanx in advance. / Josh Pritikin T It takes real genus to see \ | Internet: 6500stom@ucsbuxa.ucsb.edu | the obvious. | | AppleLink: Josh.P | Just don't say no if they | \ GEnie: J.Pritikin ! don't ask you. /
keith@Apple.COM (Keith Rollin) (12/26/89)
In article <3412@hub.UUCP> 6500stom@hub.UUCP writes: >What do the bits in VCBAtrb field mean? IV-177 sez that: > 0-4 something about inconsistencies > 6 set if volume is busy > 7 set if volume is locked by hardware > 15 set if volume is looked by software > >When I checked out my HDs and floppy I found that bit 6 was always >set and bit 5 was set only on my HDs. Bit 9 was set only on my >floppy. > >The reason I want to know this stuff is because I'm trying to write >a substitute for SFDialog and I need to know if I can eject a volume. > >Does anyone know how to detect when a volume is mounted or dismounted >without watching disk insert events or scanning the volume indexes? >Does anyone know where SFDialog gets the volume's SICNs? How do you >know if your talking to a floppy or an HD? Is it a good idea to use >the mod date to see if a volume has changed? If Finder checks the >mod date why doesn't it do it more often? Josh, You can find out if a volume is ejectable or not by using the control call described in Inside Mac V, p.470-471. Control call #23 returns, among other things, a bit that says whether or not a volume is ejectable. If the driver does not support this call number, then you can fall back on the information on page II-128, where it discusses the 4 bytes that preceed the drive queue entry. If you have access to our Q&A stack, then you can find all of this information in there. Standard File hardcodes its icons. They are not SICNs or anything like that at all. They are DC.W's embedded in the source code. It determines which one to use by looking at the size of the drive. If it's over some arbitrary limit like 2 meg, then it uses the hard disk icon. Otherwise, it uses the floppy drive icon. I don't know about the mod date business. It seems to me that updating of the modification date is inconsistant. For instance, say you have folder B within folder A which is on hard disk H. Also say that you add a file to folder B. The mod date for folder B will reflect the date/time when you added the file, but the mod date for folder A will not. I don't know how this affects the mod date for hard disk H without playing around with it some. Please be careful how you use your standard file replacement. Remember that MultiFinder patches StdFile so that it can fake an already running application into opening a document that is double-clicked on in the Finder. If you don't replease the actual PACK resource and call the normal PACK traps for StdFile, your application will not take advantage of this hack...uh, feature. -- ------------------------------------------------------------------------------ Keith Rollin --- Apple Computer, Inc. --- Developer Technical Support INTERNET: keith@apple.com UUCP: {decwrl, hoptoad, nsc, sun, amdahl}!apple!keith "Argue for your Apple, and sure enough, it's yours" - Keith Rollin, Contusions