===============================================================================
assorted - Assorted functions                                        2006-02-25


DESCRIPTION

    Some functions have been taken out of libHX because they are largely unused
    in code I write. Since there are currently not too many users of libHX that
    seem to need these functions, they currently remain out.


SYNOPSIS

    size_t HX_pack(char *fmt, size_t len, ...);
    int HX_tofrac(size_t *num, size_t *denom, double arg);


HX_pack()

    Mimics perl's pack function. FMT can contain:

      A    Pascal-style string: a uint8_t length specifier and a string
           with up to 255 chars
      a    (same)
      C    encode as uint8_t
      c    encode as int8_t
      H    encode as uint16_t
      h    encode as int16_t
      L    encode as uint32_t
      l    encode as int32_t
      S    Like A, but with a uint16_t length specifier and a string
           with up to 64K chars
      s    (same)
      V    fixed-size string; first argument is string, second is length

    Example:

      HX_pack(dest, sizeof(dest), "LLSV", 1337, 2006, "64k test string",
              "fixed test", 5);

    will produce this byte sequence on x86:

      39 05 00 00        1337
      D6 07 00 00        2006
      0E 00              15
      36 34 6B 20 74 65  "64k test string" (length=15)
      73 74 20 73 74 72
      69 6E 67
      66 69 78 65 64     "fixed"


HX_tofrac()

    Calculates a readable fraction (i.e. 1/3) from arg and puts the
    *numerator into num, the denominator into *denom. Since the fraction
    is found out by an iterative loop, you can specify the minimum value
    of the denominator in *num and the maximum value of the denominator
    into *denom before calling the function.

    If a suitable fraction has been found (within the range of the
    minimum / maximum denominator, *num and *denom will be overwritten
    with the results and 1 is returned; 0 for no success.

    You need to re-put your min/max denom values into *num and *denom
    then.