Re: [Libcdio-devel] OSX SCSI MMC commands via PLScsi?

[Steven M. Schultz]

On Sat, 25 Mar 2006, R. Bernstein wrote:

> I came across this interesting link to a program called PLScsi
>   http://members.aol.com/plscsi/mac/
> 
> But the usual OSX caveat applies. From http://members.aol.com/plscsi/mac/
> 
>    Second nastiest remaining technical issue are the significant side
>    effects of the open/ close in the launch-open-ioctl-close-exit
>    sequence that's fundamental to the idea of plscsi at the command
>    line.  In Mac OS X, open works only if preceded by diskutil unmount
>    (that's "unmount" not "umount"), and close provokes automount, ouch.

        That sounds very much like the same problem that has come up in the
        past - that of getting an 'exclusive access reservation'.  Without
        that you need to be the owner of the device, issue an unmount, do your
        command, but then the kernel/system goes and remounts the device  when
        the program closes.

        Maybe not 100% the same thing but it sure sounds similar/familiar.

        OSX is an interesting system but its I/O model sure strikes me as
        being baroque - not as nice as BSDi ;)

        Cheers,
        Steven Schultz