Practice with nonblocking IO.

1. Nonblocking reads from a FIFO

Goal: To write a program which prints a '.' character every half-a second unless some input is provided on a fifo file.

Hints:

Try to put the terminal into noncanonical mode (you want to turn off line buffering) and remove terminal echo See 'man termios' or Google "noncanonical mode" for that.
Note that you should restore the terminal mode before quitting since otherwise the terminal might get messed up (no echo).
Working with bits:

flags &= ~NEWFLAG   // Clears the bit NEWFLAG on flags
flags |= NEWFLAG    // Set the bit NEWFLAG on flags
flags ^= NEWFLAG    // Toggle NEWLAG

2. Reading from stidin

Goal: To write a program which echoes characters on screen while typed until button 'q' is pressed. Then it quits and prints a newline.

Hints:

Use open() with O_NONBLOCK flag.
If read() does not have anything to read, it returns with -1 and sets errno to constant EAGAIN - you can check that or try messing around with select() function.
FIFO can be made with a 'mkfifo fifoname' command and written to using 'cat > fifoname'.
You have to open fifo before reading (open two terminal windows).
Write your output with write() function to bypass line buffering (or turn it off).
Function usleep() can be used for half-a second pause here.