Comparing drive sizes

[shadow]

Ok so i used GetDiskFreeSpaceEx and StrFormatByteSize64 to get a drive size.  Then I used StrTrim to cut off the space and the GB/MB/KB ending.  Now I am left with a number like 3.02 .  Now I want to compare this with a number so that I can prevent a file from being installed on a drive that's too small.  lstrcmp doesn't seem to function properly for this.  What can I do to make sure when mainbuffer1 is less than minsize, it gives an error?  Minsize is in GB.

Code Select Expand


.data
minsize db "18.00",0
kb db " K",0
mb db " M",0
gb db " GB",0

.data?
mainbuffer db 4000 DUP (?)
mainbuffer1 db 4000 DUP (?)

.code

invoke GetDiskFreeSpaceEx,addr mainbuffer,addr size1,NULL,NULL
invoke StrFormatByteSize64, size1, size1+4, ADDR mainbuffer1, SIZEOF size1
invoke SetDlgItemText,hWin,IDC_EDT2,addr mainbuffer1
invoke StrTrim,addr mainbuffer1,addr kb ;*****if StrFormatByteSize64 outputs in KB, the drive is too small*****
.if eax==1
invoke MessageBox,hWin,addr smallt,addr smallc,MB_OK+MB_ICONERROR
ret
.endif
invoke StrTrim,addr mainbuffer1,addr mb ;*****if StrFormatByteSize64 outputs in MB, the drive is too small*****
.if eax==1
invoke MessageBox,hWin,addr smallt,addr smallc,MB_OK+MB_ICONERROR
ret
.endif
invoke StrTrim,addr mainbuffer1,addr gb
.if eax==1 ; *****StrFormatByteSize64 Gives us a GB output..*****
invoke lstrcmp,addr mainbuffer1,addr minsize ;*****"<space>GB" is now cut out of mainbuffer1... compare it with minsize*****
.if eax==-1 ;####PROBLEM  eax is always positive no matter what size mainbuffer1 is or minsize####
invoke MessageBox,hWin,addr smallt,addr smallc,MB_OK+MB_ICONERROR
ret
.else
jmp sizeok
.endif
invoke MessageBox,hWin,addr smallt,addr smallc,MB_OK+MB_ICONERROR
.endif
sizeok:
; and out...


I have a feeling lstrcmp doesn't like decimal points. 
hmm... thanks in advance folks!  :wink

[Rifleman]

shadow,
Convert the number to a string then do your compare and all will work well.

PBrennick

[shadow]

how do I convert it to a string?

[farrier]

shadow,

Unless you need to compare the strings, compare the raw numbers:

Code Select Expand


struct DISKSIZE
.dwLowSize dd ?
.dwHighSize dd ?
ends

avail_bytes DISKSIZE
total_bytes DISKSIZE
free_bytes DISKSIZE
file_bytes DISKSIZE


invoke GetDiskFreeSpaceEx, [edi], avail_bytes, total_bytes, free_bytes
invoke GetFileSizeEx, [hYourFile], file_bytes
mov eax, [avail_bytes.dwHighSize]
cmp eax, [file_bytes.dwHighSize] ;avail - file
ja .enough_room
jb .not_enough
mov eax, [avail_bytes.swLowSize]
cmp eax, [avail_bytes.dwLowSize] ;avail - file
jae .enough_room
.not_enough:


hth,

farrier

ps. Don't you wish we all had 64 bit registers!

[shadow]

I have never used struct before.  where does

Code Select Expand

avail_bytes  DISKSIZE
total_bytes DISKSIZE
free_bytes DISKSIZE
file_bytes DISKSIZE go? hmmm that totally confused me  :red  I'll bet i have a few juicy 64 bit registers in this AMD 3500 here...  If only  I could use them :(.

[farrier]

shadow,

Use:

Code Select Expand

DISKSIZE struc
   dwLowSize dd ?
   dwHighSize dd ?
DISKSIZE ends

instead!  I posted FASM code by mistake.

farrier

[shadow]

hehe i got that one from the MASM documentation on STRUCT... Now that I've gotten some sleep... did you mean

Code Select Expand

avail_bytes dd DISKSIZE
total_bytes dd DISKSIZE
free_bytes dd DISKSIZE
file_bytes dd DISKSIZE
?

[Mark Jones]

No Shadow,

Code Select Expand


DISKSIZE struc
   dwLowSize dd ?
   dwHighSize dd ?
DISKSIZE ends

.data?
avail_bytes DISKSIZE<>
total_bytes DISKSIZE<>
free_bytes DISKSIZE<>
file_bytes DISKSIZE<>

.code


[farrier]

Thanks Mark! :red

farrier

[shadow]

I'm understanding the idea behind this now, the high and low parts of the 64 bit qword value are 32bits each.  :U   The size I want to compare with the drive size is 19330000000 bytes; the sum of 30 seperate files. 19330000000 doesn't fit into any 32 bit registers.  How do I get 19330000000 into file_bytes?  :'(

[Jeff]

theres a number of ways to approach this.  the size would require about 10 bytes.  for starters, you could use the TBYTE (10 byte) type.

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.data?
avail_bytes TBYTE ?
total_bytes TBYTE ?
free_bytes TBYTE ?
file_bytes TBYTE ?
to make things a wee bit easier for you, you could make a few adjustments to the structure:

Code Select Expand

DISKSIZE struc
   dwLowSize dd ?
   dwHighSize dd ?
   wHighHighSize word ?       ;doubleword might be wise
DISKSIZE ends

.data?
avail_bytes DISKSIZE <>
total_bytes DISKSIZE <>
free_bytes DISKSIZE <>
file_bytes DISKSIZE <>

.codesame size but easier to get at the numbers a bit

it can be as large as you want, its just a matter of coding the manipulation (80bit addition, multiplication, etc)
sorry, bad advice, please ignore

[shadow]

hmm I think it has more to do with how I am actually moving the data into file_bytes.

Code Select Expand



.data
size12 db "19330000000",0

.data?
DISKSIZE struc
   dwLowSize dd ?
   dwHighSize dd ?
   dwHighHighSize dword ?
DISKSIZE ends


.data?
avail_bytes DISKSIZE <>
total_bytes DISKSIZE <>
free_bytes DISKSIZE <>
file_bytes DISKSIZE <>

mainbuffer db 4000 DUP (?)
mainbuffer1 db 4000 DUP (?)

.code
invoke GetDiskFreeSpaceEx,addr mainbuffer,addr avail_bytes,addr total_bytes,addr free_bytes

;--

invoke lstrcpy,addr file_bytes,addr size12 ;doesn't seem to work...
;I tried mov too, but registers aren't big enough.

;--

mov eax, [avail_bytes.dwHighSize]
cmp eax, [file_bytes.dwHighSize] ;avail - file
ja enough_room
jb not_enough
mov eax, [avail_bytes.dwLowSize]
cmp eax, [avail_bytes.dwLowSize] ;avail - file
jae enough_room



not_enough:
invoke MessageBox,hWin,addr smallt,addr smallc,MB_OK+MB_ICONERROR
ret

enough_room:

ret


[Jeff]

oh im sorry, the API was coded specifically using ULARGE_INTEGER structures.  i thought you were going to code the changes.

[edit]
whoa i really screwed up really sorry.  the structure that you had was sufficient.  take out the dwHighHighSize part.  if you want to manipulate the numbers for avail_bytes, total_bytes, etc, you have to work with them 32bits at a time.

[shadow]

It's alright!  Everyone makes mistakes  :red  Do I have to split 19330000000 into 32 bit chunks to copy it to avail_bytes?  How would I do that?  Hmmm... I never thought writing an installer program would be so difficult!  I'm leanring a lot though!  thanks folks!

[Jeff]

so sorry again.  :)  let me try this again.

I'm understanding the idea behind this now, the high and low parts of the 64 bit qword value are 32bits each. :U The size I want to compare with the drive size is 19330000000 bytes; the sum of 30 seperate files. 19330000000 doesn't fit into any 32 bit registers. How do I get 19330000000 into file_bytes? :'(

size12 is a number string.  to make things easier, you should convert this to a "DISKSIZE number".  i dont know what API functions to use but you can always use the windows calculator (one of our best friends).  ;)

according to the calculator, 19330000000 is 00000004 80286480 in hex. so in code, you could use this:

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.data
size12 DISKSIZE <80286480h,00000004h>    ;low 32bits first since little endian, then high 32bits

i hope ive redeemed myself.  :)