Preferences.dat file

Description

This file used to store eMule's configuration in it's earlier versions. Nowadays, it only stores the userhash and the configuration file version.

Data

The current configuration file version is 20 (in hex: 0x14).

Format

The file format is as follows:

VersionUserhashLengthFlagsShowcmdMaxpositionxMaxpositionyMinpositionxMinpositionyNormalpositionleftNormalpositiontopNormalpositionrightNormalpositionbottom

As you can see, all the fields are stored without any separator character. This is done like this all the fields have a specific size:

• Version: 1 byte
• Userhash: 2 bytes
• Length: 4 bytes
• Flags: 4 bytes
• Showcmd: 4 bytes
• Maxpositionx: 4 bytes
• Maxpositiony: 4 bytes
• Minpositionx: 4 bytes
• Minpositiony: 4 bytes
• Normalpositionleft: 4 bytes
• Normalpositiontop: 4 bytes
• Normalpositionright: 4 bytes
• Normalpositionbottom: 4 bytes

The relevant fields are the following:

• Version: Specifies the configuration file version (the format defined in this articles corresponds to version 20).
• Userhash: The userhash.
• Length: Length in bytes of the file not counting th Version and Userhash fields (should be 38 bytes).

Once this data is put together, it is stored in little-endian.

Example

The following is a hex dump of an hypothetic preferences-dat file:

a3143e6f12dd445b12a0c3c6f7ca5b2d00230000000000000000000000000000000000000000000000000000

In the above example, the following data can be seen:

• Configuration file version: 20 (In hex: 0x14)
• Userhash: A36F3EDD125B44A012C6C3CAF72D5B23
• Other fields: ---

Extra

aMule ignores the main window position, main window size, showcmd, flags and length fields in this file. That's the reason why this fields aren't specified in this article.