printf format strings

%d     : integer
%5d    : integer in a field of width 5 chars
%-5d   : integer in a field of width 5 chars,
         but adjusted to the left
%05d   : integer in a field of width 5 chars,
         padded with zeroes from the left
%g     : float variable in %f or %g notation
%e     : float variable in scientific notation
%11.3e : float variable in scientific notation,
         with 3 decimals, field of width 11 chars
%5.1f  : float variable in fixed decimal notation,
         with one decimal, field of width 5 chars
%.3f   : float variable in fixed decimal form,
         with three decimals, field of min. width
%s     : string
%-20s  : string in a field of width 20 chars,
         and adjusted to the left