Skype since version 4+ is using SQLite DB to store everything. Use can standard tools to extract anything you need.
skypelog.py -- read and save Skype Linux chat history in Python.
Skype for Linux stores user chat history in binary *.dbb files. skypelog.py implements classes to easily access data in these file in Python.
I couldn't find a working solution for Linux to export/backup chat history. D-Bus API does not give access to old messages, at least I couldn't make it work. (possibly a bug, in theory it should work and there is evidence that it did before).
The information on the structure of the DBB files is quite scarce. This script can serve as a starting point to further investigate the format of these files.
Running the script directly will show two basic options --json {compact,full} dump chat messages into single js file (for each account) compact - saves only basic information, full - everything output is unsorted and lacks wrapping curly braces --html save conversations for each account/contact pair in a separate *.html file (relies on 'dialog_partner', so group chats are not handled properly)
One can use skypelog.py as a module, then the following classes will be useful: (see example in apiuse.py)
class SkypeDBB -- generic DBB file reader init requires file name and (optionally) maximum record size maximum record size can be determined from the file name if omitted (e.g. chatmsg512.dbb has maximum record size 512) records() -- iterates over all records in file returns dictionary with numeric field types as keys readrecord(NUM) -- returns dictionary for NUM'th record in file (counts from 0)
class SkypeObject -- base class for DBB records
class SkypeMsgDBB(SkypeDBB) -- chatmsgDDDD.dbb file reader reading methods return SkypeMsg instead of 'dict'
class SkypeMsg -- provides human-readable field names for chat message record formatting function to convert to full JSON (with all fields) and shortened versions of JSON and HTML (as in client UI)
class SkypeAccDBB(SkypeDBB) -- profileDDDD.dbb file reader reading methods return SkypeAcc instead of 'dict'
class SkypeAcc -- provides human-readable field names for account record
class SkypeContactDBB(SkypeDBB) -- userDDDD.dbb file reader reading methods return SkypeContact instead of 'dict'
class SkypeContact -- provides human-readable field names for contacts record
Interesting discussion of the *.dbb file format: http://www.hackerfactor.com/blog/index.php?/archives/231-Skype-Logs.html http://www.hackerfactor.com/blog/index.php?/archives/231-Skype-Logs.html#c1055