• Keyboard: Yamaha YPT-220
• Software: Sekaiju 2.8 (Free GPL, Windows 7 64b)
• MIDI to MP3 converter: http://solmire.com
• Video Software: Microsoft Windows Movie Maker
• This work is available in MIDI or MP3 format for free if anyone is interested

DIR_SEP="\\" --should be "/" for Unix platforms (Linux and Mac)
function browseFolder(root)
	for entity in lfs.dir(root) do
		if entity~="." and entity~=".." then
			local fullPath=root..DIR_SEP..entity
			--print("root: "..root..", entity: "..entity..", mode: "..(lfs.attributes(fullPath,"mode")or "-")..", full path: "..fullPath)
			local mode=lfs.attributes(fullPath,"mode")
			if mode=="file" then
				--this is where the processing happens. I print the name of the file and its path but it can be any code
				print(root.." > "..entity)
			elseif mode=="directory" then
				browseFolder(fullPath);
			end
		end
	end
end

--this is a sample call
browseFolder(".")

---checks if a string represents an ip address
-- @return true or false
function isIpAddress(ip)
 if not ip then return false end
 local a,b,c,d=ip:match("^(%d%d?%d?)%.(%d%d?%d?)%.(%d%d?%d?)%.(%d%d?%d?)$")
 a=tonumber(a)
 b=tonumber(b)
 c=tonumber(c)
 d=tonumber(d)
 if not a or not b or not c or not d then return false end
 if a<0 or 255<a then return false end
 if b<0 or 255<b then return false end
 if c<0 or 255<c then return false end
 if d<0 or 255<d then return false end
 return true
end

And here are some tests:

assert(isIpAddress("1.1.1.1")==true)
assert(isIpAddress("255.1.1.1")==true)
assert(isIpAddress("255.255.0.0")==true)
assert(isIpAddress("0.0.0.0")==true)
assert(isIpAddress("255.255.255.255")==true)
assert(isIpAddress("0.0.0.1")==true)
assert(isIpAddress("0.0.1.1")==true)
assert(isIpAddress("0.1.1.1")==true)
assert(isIpAddress("1.2.3.4")==true)
assert(isIpAddress(nil)==false)
assert(isIpAddress("")==false)
assert(isIpAddress("1")==false)
assert(isIpAddress("1.2")==false)
assert(isIpAddress("1.2.3")==false)
assert(isIpAddress("1.2.3.4.")==false)
assert(isIpAddress(".1.2.3.4")==false)
assert(isIpAddress("0")==false)
assert(isIpAddress("-1")==false)
assert(isIpAddress("256")==false)
assert(isIpAddress("-1.2.3.4")==false)
assert(isIpAddress("1.-2.3.4")==false)
assert(isIpAddress("1.2.-3.4")==false)
assert(isIpAddress("1.2.3.-4")==false)
assert(isIpAddress("256.2.3.4")==false)
assert(isIpAddress("1.256.3.4")==false)
assert(isIpAddress("1.2.256.4")==false)
assert(isIpAddress("1.2.3.256")==false)
assert(isIpAddress("256.256.256.256")==false)
assert(isIpAddress("1000.0.0.0")==false)
assert(isIpAddress("a.b.c.d")==false)
assert(isIpAddress("a.2.c.d")==false)
assert(isIpAddress("a.b.3.d")==false)
assert(isIpAddress("a.b.c.4")==false)

1. 128.0.0.0
2. 192.0.0.0
3. 224.0.0.0
4. 240.0.0.0
5. 248.0.0.0
6. 252.0.0.0
7. 254.0.0.0
8. 255.0.0.0
9. 255.128.0.0
10. 255.192.0.0
11. 255.224.0.0
12. 255.240.0.0
13. 255.248.0.0
14. 255.252.0.0
15. 255.254.0.0
16. 255.255.0.0
17. 255.255.128.0
18. 255.255.192.0
19. 255.255.224.0
20. 255.255.240.0
21. 255.255.248.0
22. 255.255.252.0
23. 255.255.254.0
24. 255.255.255.0
25. 255.255.255.128
26. 255.255.255.192
27. 255.255.255.224
28. 255.255.255.240
29. 255.255.255.248
30. 255.255.255.252
31. 255.255.255.254

The following Lua script was used to calculate those values:

map={
  ["00000000"]="0",
  ["10000000"]="128",
  ["11000000"]="192",
  ["11100000"]="224",
  ["11110000"]="240",
  ["11111000"]="248",
  ["11111100"]="252",
  ["11111110"]="254",
  ["11111111"]="255"
}
for i=1,31 do
  s=string.rep("1",i)..string.rep("0",32-i)
  print(map[s:sub( 1, 8)].."."..map[s:sub( 9,16)].."."..map[s:sub(17,24)].."."..map[s:sub(25,32)])
end

Apparently back side of the paper I have is much better than its front side!

It’s basically these lines that made it work:

$ cd /etc/usb_modeswitch.d
$ sudo tar xzf /usr/share/usb_modeswitch/configPack.tar.gz 12d1:1446
$ sudo sed -i -e 's/14ac"/14ac,1506"/' 12d1\:1446

Also it seems that the following command is required for it to work:

$ sudo modprobe usbserial vendor=0x12d1 product=0x1506

After that, you need to configure Ubuntu Network Connections (the little network icon on the top right of the screen near the speaker icon). Go to “Mobile Broadband” tab, click “Add”. Select “Sweden” as your country, “Tele2″ as your operator and “Mobile Bredband” as your data plan.
Then use the following configurations:

• PIN1: ***** (your pin code)
• connection type: NDIS
• access point: mobileinternet.tele2.se
• Phone number: *99#
• Username and password: Not used (leave empty)
• Password Authentication Protocol: CHAP (to be safe you can select all of them)
• IP address: Dynamic
• DNS address : Dynamic
• WINS address: Dynamic

PS. The Linux version of the driver is really stable! I share the Internet using an Asus Eee Box and an access point to 4 other wireless devices at home. In Windows, the device used to get disconnected and sometimes it had to be removed from the USB port and inserted again (even when using the latest driver from Huawei). In Linux this hasn’t happened during the last week.