s = io.read("*n") -- read a number
 s = io.read("*l") -- read a line (default when no parameter is given)
 s = io.read("*a") -- read the complete stdin
 s = io.read(7) -- read 7 characters from stdin
 x,y = io.read(7,12) -- read 7 and 12 characters from stdin and assign them to x and y
 a,b = io.read("*n","*n") -- read two numbers and assign them to a and b