arden@creed.UUCP (Bruce Arden) (03/27/85)
I have a program that needs to keep a file open for a long time. How can I be sure that someone hasn't changed the disk since I opened the file? I noticed a 'MEDIA CHECK' command for device drivers, but I can't find any system call to do this check. I am using mostly 'Xenix compatible' system calls under PCDOS 2.0. -- Bruce Arden ..!mcvax!ukc!stc-a!creed!arden
nather@utastro.UUCP (Ed Nather) (03/28/85)
> I have a program that needs to keep a file open for a long time. > How can I be sure that someone hasn't changed the disk since I > opened the file? > > Bruce Arden > ..!mcvax!ukc!stc-a!creed!arden If the disk in question has a file on it you can be sure has a unique name (perhaps you could write one on it you're sure would be unique) then you can search the disk for its existence. In a .bat file, the "If exist filename ..." does that job. Apparently DOS does it that way -- you can swap disks around if they have the same directory names, and are "in" a subdirectory -- and DOS will leave you there, on the new disk, if it hasn't seen you refer to that drive and been unable to find the path it last saw. -- Ed Nather Astronony Dept, U of Texas @ Austin {allegra,ihnp4}!{noao,ut-sally}!utastro!nather