Shouldnt be too hard to work out how it is calculated with a little reverse engineering :BL:

I noticed your post says something about how many sources there are. How did you calculate this? I found it difficult to do so bcoz the user/filename strings seemed to be variable length?

it simply works, when you assume, that the data block after the filename is
of a fixed length (it should be around 141 Bytes(maybe +-1).
thus if you walk through it, adding

length(filename)+141

for each user (count is the 1. dw as you guessed), you get to the main data
block, which more or less resembles the data in the .dbb file

indy

hmm looks like i've overlooked some stuff in my examination of the DAT file. the repairer actually counts the number of sources by counting the number of @ surrounded by alphanumeric chars (the character after it can only be an M for musiccity, a K for Kazaa, a G for Grokster or ? for unknown)

so, if the pointer was corrupt and wouldnt go back far enuff, so u had to start at the end of the list (well, the end of the file, is it possible to find the end of the list from the end of the file?) how would you work your way back?

lets think of a kind of "matched" decoder

we have the rough structure for 1 found user:

byte 1 or 0 //always beetween users, has to be replaced by dw 1 later
string, byte 0 //filename + 0
bytearray [140] //maybe its 139 or 142
--- start of main block
dw nparms //doubleword number of parameters
loop nparms // repeated nparms
dw ptype1 // doubleword parametertype
dw plength // doubleword parameterlength
bytearray [plength] //parameter
end loop
bytearray [12] //unknown parms 12+-1
string downloadpath + byte 0 //filename downloadpath +0
bytearray [29] //unknown parms
string "KAZAAxxyyyy" //Kazaastring
EOF //end of file

just write a decoder or statemachine that resembles this structure,
then let it loop with an increasing offset from the
end of file, if it gets ready exactly with EOF - :beer:bingo:beer:.

at least you can try
indy
:J:

thx 4 possting in whats .DAT indy now ive take the the time to read this rapidly evolving thread
good work to all involved
will be getting pearl in the box in the next few weeks and trying to work this out
good work
kewbase
on
startfiles
do u reckon can i link to your page from morphia ?

Been poking around some DAT files and found some more info ( can't believe I missed it first time around :eek: ) do let me know if this is news to you indy ( also I've only got two DAT files to play with atm so I'm hoping this is applicable to all DATs )

I've been taking a look at the filename/user object and I've dissected it this far:

1. Filename. This is a variable length string of the filename as it is stored on the source's computer

2. 30 byte array. This appears to be another kind of signature or some such. Originally I mistook it for uninitialised memory/hard disk space but I noticed it is identical for every user

3. 16 byte array. Still not sure what this is. I can say unlike the previous array it does differ from user to user

4. 95 byte user name array. The username, unlike the filename appears to be fixed at 95 bytes.

And of course 95 + 16 + 30 = 141 a value which indy has already quoted to me.

That's all for now, I'm checking out the end of the file values which we haven't been able to identify yet

:cr:

PS: If ya need extra web space to provide a link for files that are too large
for the attachment feature on this forum, or other things if they're not too
big ...no problem ...let me know and I will upload them and tell you the link.

Also, I just got to thinking. Couldn't one make a self extracting zip file that
unzips to the download folder and automatically opens Morpheus when it is
finished? Like so>

u2boy.exe <click ...(the start files for one of my favorite albums of all time)...U2 - Boy

However...I suppose the download folder and program location would have
to be the default. Could it maybe "find" it? I'll leave that to you wizards!;)

PS: I made the start files like Kewbase said, but my zip file turned out to be kinda large.:dunno:

Finding the executable path and download directories is easy via the registry :D

Next version of my program MorpheusX ( http://go.to/MorpheusX ) acts as a loader and does this.

@AYB:
as far as i've analyzed the user field, it consists of the following

string filename, byte 0, byte 0 //filename +0+0
dw maybe_some_flags //dont knows, differs from user 2 user
bytearray[20] //signature same a parm 3 in main block
dw filesize //filesize in bytes
dw user-ip //
dw user-port //usually 1214
dw supernode-ip
dw supernode-port //usually 1214
string username, byte 0 //username
bytearray [141-tillthere] //don't know, differs

@Maze
the part of .dat, which contains the folder, where the downloaded
file is finally placed is protected through checksum, therefore, if
you will change this folder, you have to change it in dat and
recalculate the checksum.

indy

:f:

once again indy this is great work

also serves to highlight how incompetent :BB: these programmers are once again - port only needs to be a word

username definately seems to me to be fixed at 95 bytes ( you say it differs? :con: )

also, you say the dword following the double null terminating the string is different, on the DAT files I have they seem to be the same :con: but distinct from the 20 byte array bcoz this can also be found in the footer after the strings which are clearly song name, artist, description etc

:RS:

is morpheusX going to have some startfile idea involved ?
i sure you will let us know when it is released
but iam happy to try it out before that if you need another tester

It's possible MorpheusX will incorporate something involving start files ;)

Right now I barely managed to get v0.2 out by the end of january, which was my self imposed deadline :eek: and I've got plenty of work to do for uni so... need a couple weeks for things to clear up :tu:

program that views & manages .dat files
 

hi!

THANKX to all u for guessing all this info about the .dat files format... it has simplified my work... :TY:

i've developed a program that shows .dat info and let a user to obtain the downloaded data on various ways...
u all can try it at: http://www.angelfire.com/ego2/idleloop

(and i've complete a little the structure of .dat files... :ND: )

GreEtiNgs! :W:

GreEtiNgs idleloop!:tu: thanks for stopping in. nice site btw. the guys who invented ft sigdats are napsterites.net members and they've been known to help out w/info when they stop by from time to time. :beer:

- js.

:tu::beer::tu:
indy