Programming Forums > Application Development > C++

DiSA · Sep 24th, 2004, 5:36 PM

quite an odd question...
Does anyone know how can i get the start cluster(first cluster of cluster chain) number of a particular file in a fat32 filesystem running under windows? Is this possible at all? or windows won't let me...?
i'd appreciate any comments, suggestions... thanks!

Ashcroft · Sep 24th, 2004, 6:10 PM

Been a while since I did low level code like that but you want the 0x21 "OS" interrupts, there are some other BIOS interupts (0x25, 0x26) but they will not be nearly as portable as these.

http://msdn.microsoft.com/library/default..../fat32_70z4.asp

DiSA · Sep 25th, 2004, 4:28 PM

thanks a lot, i'll take a look. but i think this is only for win 9x, and i'm wornking under nt, think i forgott to say that...

kurifu · Sep 27th, 2004, 2:15 PM

I do not think that windows exports API functions that will grant you low level access to the Disk... as of Windows 2000 you can not even get low level access to the disk without making Windows Angry. Windows will lock it on you, you actually have to reboot and execute your program in the startup so that you can bypass Windows in those circumstances.

DiSA · Sep 27th, 2004, 3:09 PM

rebooting is not an option... but i've found something in windows sdk, DeviceIoControl with FSCTL_GET_RETRIEVAL_POINTERS, I think that may be the solution, i have to give it a try...
Thanks!

Berto · Sep 28th, 2004, 2:11 AM

I would of thought you could read from it but i would doubt you can write direct to it without windows's permission.

DiSA · Sep 28th, 2004, 7:49 AM

you may be right, but I just need to read it... so it doesn't matter to me
thanks

Sep 27th, 2004, 2:15 PM	#4
kurifu Expert Programmer Join Date: Jul 2004 Location: Halifax, Nova Scotia (Canada) Posts: 784 Rep Power: 5	I do not think that windows exports API functions that will grant you low level access to the Disk... as of Windows 2000 you can not even get low level access to the disk without making Windows Angry. Windows will lock it on you, you actually have to reboot and execute your program in the startup so that you can bypass Windows in those circumstances. __________________ Clifford Matthew Roche <geek@cliffordroche.com> Web Hosting: http://www.crd-hosting.com Consulting: http://www.crdev-consulting.com

Sep 28th, 2004, 2:11 AM	#6
Berto Programming Guru Join Date: Aug 2004 Posts: 1,022 Rep Power: 6	I would of thought you could read from it but i would doubt you can write direct to it without windows's permission. __________________ "Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT'S relativity." - Albert Einstein

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Sep 24th, 2004, 5:36 PM	#1
DiSA Newbie Join Date: Sep 2004 Posts: 4 Rep Power: 0	quite an odd question... Does anyone know how can i get the start cluster(first cluster of cluster chain) number of a particular file in a fat32 filesystem running under windows? Is this possible at all? or windows won't let me...? i'd appreciate any comments, suggestions... thanks!

Sep 24th, 2004, 6:10 PM	#2
Ashcroft Programmer Join Date: Sep 2004 Posts: 38 Rep Power: 0	Been a while since I did low level code like that but you want the 0x21 "OS" interrupts, there are some other BIOS interupts (0x25, 0x26) but they will not be nearly as portable as these. http://msdn.microsoft.com/library/default..../fat32_70z4.asp

Sep 25th, 2004, 4:28 PM	#3
DiSA Newbie Join Date: Sep 2004 Posts: 4 Rep Power: 0	thanks a lot, i'll take a look. but i think this is only for win 9x, and i'm wornking under nt, think i forgott to say that...

Sep 27th, 2004, 3:09 PM	#5
DiSA Newbie Join Date: Sep 2004 Posts: 4 Rep Power: 0	rebooting is not an option... but i've found something in windows sdk, DeviceIoControl with FSCTL_GET_RETRIEVAL_POINTERS, I think that may be the solution, i have to give it a try... Thanks!

Sep 28th, 2004, 7:49 AM	#7
DiSA Newbie Join Date: Sep 2004 Posts: 4 Rep Power: 0	you may be right, but I just need to read it... so it doesn't matter to me thanks

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Programming Forums > Application Development > C++

Low Level Hd Access