I want to start learning C again. I did this over 10 years ago, but did not like C, so I moved on. However, there is an operating system that I am very interested in writing applications for and the main language available right now is C.

I used to have the very popular C book by Kerninghan and Richie, but I lost it. I really don't want to buy this book again anytime soon. Are there any nice C learning information sources online that I can use until I can buy the book again?

www.google.com->C tutorial

If you just want a "reference book":
http://cppreference.com/

It even has a search plugin for firefox (cf mycroft site). Extremely useful!

And if you speak french:
http://www.siteduzero.com/

For online, I like http://www.le.ac.uk/cc/tutorials/c/. Unfortunately, my favorite site (www.functionpointer.org) seems to be dead.
For physical books, K&R is good. IMHO the book by Darnell and Margolis is even better.

don't forget of course, all the std libraries and functions
are man pages also. So you don't really need a
full blown reference manual.

Wow, I never knew I could look up function prototypes with man.
I always thought man pages were only for unix commans and installed progs.
Thanks for the tip.
Now I know where to get help when offline.

yeah loads of stuff (on solaris anyway)
eg man limits brings up <limits.h> as a man page.

Yeah, Linux is the platform... just install GCC and you are away!

I revisited C programming again from having to do so 10 years ago... what I learnt then about C was all forgotten. I had to start again, etc memory allocation, structures, binary trees, etc...

All very interesting stuff... keeps me busy at work during work hours

Thanks guys!
There are some nice links there. I really like the one from larrynewt. It looks like a nice little course on C.

The applications I plan to write will be for AROS or Amiga Research Operating System. Even though I have been using Linux for many years, I have never let go of my Amiga roots. So helping with AROS is very interesting to me. It's open source and Amiga related, so I like it a lot!
http://www.aros.org

But I am running it as a hosted environment in Linux, so I will be using Linux to develop. The C compiler is geared towards AROS though.

It helps to learn when u have goals in mind such as you have.
Be patient.
Good luck.