String value compare question

[LCF-AT]

Hi guys,

I have a short question again.I build a listview and show filenames & filedates into etc and now wanna add a sort function for the datetime.So it means I have to compare the datetime strings.How can I do this on a easy way?My format I use is this..like in explorer

03/12/2016 20:15:30
23/11/2015 21:05:32

Day,Month,Year,time.So can I compare it maybe at once anyhow?

greetz

[kao]

Best solution would be to compare actual datetimes, not strings..  

One of the most common solutions is to store date value in LVITEM lParam field - this value is sent to your sorting function. See https://msdn.microsoft.com/en-us/library/windows/desktop/bb774760(v=vs.85).aspx and http://masm32.com/board/index.php?topic=610.0 and http://win32assembly.programminghorizon.com/tut31.html

[LCF-AT]

Hi kao,

thanks so far.Problem is I have already the strings as I did post above.Now I don't wanna change them back etc.So can I not compare both strings with wsprint API with any pattern etc?So if not then I have to handle and check the entrys manually (Year to hex x2 compare which is higher.If same check next entry of month etc).

greetz

[kao]

Yes, you can also scratch your left ear with your right foot. However, it's gonna be terribly uncomfortable. :-)

[cob_258]

if the date format was YYYY/MM/DD strcmp would work fine, try to split it (the date) and concatenate it backward (I don't know which language you're using, so I'm not sure if this will help you)

[kao]

@cob_258: LCF-AT is hardcore and uses only assembly.

@LCF-AT: Something like this could work - but it's a very inefficient and horrible hack that relies on your specific time formatting: http://pastebin.com/UtUDTJLs

[cob_258]

@kao @LCF-AT not sure about this information but maybe setting direction flag to 1 may cause strcmp to work backward, I say this because once this API was crashing when I used STD instruction just before calling it

EDIT : the API is lstrcmp not strcmp (my bad), I tested it under win8.1 x64 and it seems that it has been fixed

Edited April 7, 2016 by cob_258

[TheProxy RE]

https://msdn.microsoft.com/en-us/library/system.datetime.compare(v=vs.110).aspx

and to parse datetime fro mstring
 

string dateTime = "01/08/2008 14:50:50.42";
DateTime dt = Convert.ToDateTime(dateTime);

Edited April 7, 2016 by TheProxy RE

[cob_258]

@LCF-AT since your're using asm (and I didn't  code in asm for a long time) I've written this function that compares date (only) in the format you use

DateCompareBackward.rar

[LCF-AT]

Hey guys,

thanks for your help so far so I will check the asm codes you did posted. Hey kao,your example code does look almost as mine I tried to build yestersay.Many compare command.

Thanks again so far guys and till later.

PS: I also tried to use the time "DateTime.inc" with some functions I found inside like "StringToDateTime" etc but WinASM does show me a external error "unresolved external symbol _StringToDateTime@8" so don't remember anymore how to fix that kind of errors.

greetz

[cob_258]

@LCF-AT if you're interested in conversion I've written another version that convert from string to dword than do the comparison, and this function is smaller (93byte) than the previous (110byte)

DateCompareBackward_1.rar

[LCF-AT]

Hi guys its me again,

short another question about by sorting stuff.So in the tutorial 31 (see kao post) there I can find a name sort and a filesize sort using String2Dword function in the compare routine.Normaly it works fine but just for files which are not higher than 4 GB etc you know.Now I wanna change this so that all get sortet right by size also if files are higher than 4 GB.Now the question is what I should use now.So the size value string I got like this only in KB (123.123 kb) like in exlorer.Now I thought I should use sscanf API with I64d and then do a double compare of the qwords (first +4 compare and if same compare first dowrd of qwords).So it seems to work but problem is the . in the string.All in all I have to remove the points in the strings and move the part before the string one part to right side.Of course its again very un-handy to do this again and here I wanna ask you whether you got any better solution in your mind which I could use in that case.

greetz

[cob_258]

I'm not sure that I understand your problem but there is my idea :

if the size string you get have all the same formate (xxx.xxx Kb) all you need is to compare strings directely with 

mov ecx,size_of_strings ; obtained somehow
mov edi, offset szSize1
mov esi, offset szSize2
repe cmpsb
je @equals
	ja @size1Gsize2
	jmp @size2Gsize1
@equals:
;;;
@sizeo1Gsize2:
;;;
@size2GSize1:
;;;

the only problem with this code is that the strings must be "aligned" (not sure for the word :p) I mean the point is at the same position for both, if it's not the case it's obvious that the string with a point at a bigger offset is greather than the other (i.e xxx.xx > xx.xx)

[LCF-AT]

Hi again and thanks for your help so far.So I think your method isn't working so I need to check the values in the strings I have.Just have a look into your Windows Explorer there you can see the sizes as KB strings.

   27.560 KB
       10 KB
1.258.001 KB

I have same too I need to compare now.So I think there is also any API I could use with that strings and any xy paramters maybe and to check which is higher / lower etc.No idea now.

greetz

[cob_258]

I thought that the point is to separate decimals (I got things mixed up, my bad), still you can use the way I posted above, since they have all the same format you can begin comparing the string length (lstrlen, or repne scasb with al =0), the bigger string lenght the larger is the file, if the same use the code above

 

[LCF-AT]

Hi again,

ah ok now I see it and you're right.So now it seems to work fine. Thanks again cob_258.

greetz

[cob_258]

@LCF-AT you're welcome, glad I could help