I decided to use SDCC in Piklab (Ubuntu). Is there any manual, that teaches you using this compiler, like ccs manual? In this one, there are just some instructions how to install it and blah blah blah..nothing usefull, like how to use lcd or something.
I think you are asking multiple questions here without realising it.
If I'm reading your thread correctly you may be asking:
1. For a tutorial on the C language
2. A tutorial on a specific implementation of C
3. Instructions on how to use an LCD with C
All of these are very different questions and you may have to go to
different locations to get help.
In particular it is unlikely that you C compiler will help you with LCD programming at all unless it is part of a packaged system.
Given that you are using Linux I doubt that would be the case (but I may be wrong of course)
My advice if you are able to choose would be to go to the MikroElectronica
web site and download their free C compiler. It includes a software debugger.
This also includes a full excelent IDE and LCD libraries.
Using the libraries will work as an excelent tutorial.
This is even more helpfull as they have written a tutorial book which
they have put online free in HTML form to read. I highly recommend
having a look at this.
I realise that not everyone can pay for their compiler but the free version
is fully functional and will be enough to do more than what you are asking.
I have found them to be a very generous company.
After doing this you will be in a better position to use a lower quality
compiler/environment if you choose.
jack