d ==> integer, Signed decimal integer
    i ==> integer, Signed decimal integer
    u ==> integer, Unsigned decimal integer
    o ==> integer, Unsigned octal integer
    x ==> integer, Unsigned hexadecimal integer, using "abcdef"
    X ==> integer, Unsigned hexadecimal integer, using "ABCDEF"
    f ==> float, Signed value  having the form [-]dddd.dddd, where  dddd is
        one  or  more  decimal  digits.    The  number of digits before the
        decimal  point  depends  on  the  magnitude  of the number, and the
        number of digits after the  decimal point depends on the  requested
        precision.
    e ==> float, Signed value having the form [-]d.dddd e [sign]ddd,  where
        d is a single  decimal digit, dddd is  one or more decimal  digits,
        ddd is exactly three decimal digits, and sign is + or -.
    E ==> float, Identical  to the e format,  except that E introduces  the
        exponent instead of e.
    g ==> float, Signed value printed  in f or e format, whichever  is more
        compact for the given  value and precision.   The e format is  used
        only when the exponent of the value is less than -4 or greater than
        the  precision  argument.    Trailing  zeros  are truncated and the
        decimal point appears only if one or more digits follow it.
    G ==> float, Identical  to the g format,  except that G introduces  the
        exponent (where appropriate) instead of e.
    c ==> character, Single character
    s ==> string, Characters printed up to the first null character  ('\0')
        or until the precision value is reached.