hex (unsigned char c)
{
    buffer_put (buffer_2, "0123456789abcdef" + (c >> 4), 1);
    buffer_put (buffer_2, "0123456789abcdef" + (c & 15), 1);
}
hex (unsigned char c)
{
    buffer_put (buffer_2, "0123456789abcdef" + (c >> 4), 1);
    buffer_put (buffer_2, "0123456789abcdef" + (c & 15), 1);
}