Serialize double and float with C

Question

How can I serialize doubles and floats in C?

I have the following code for serializing shorts, ints, and chars.

unsigned char * serialize_char(unsigned char *buffer, char value)
{
    buffer[0] = value;
    return buffer + 1;
}

unsigned char * serialize_int(unsigned char *buffer, int value)
{
    buffer[0] = value >> 24;
    buffer[1] = value >> 16;
    buffer[2] = value >> 8;
    buffer[3] = value;
    return buffer + 4;
}

unsigned char * serialize_short(unsigned char *buffer, short value)
{
    buffer[0] = value >> 8;
    buffer[1] = value;
    return buffer + 2;
}

Edit:

I found these functions from this question

Edit 2:

The purpose of serializing is to send data to a UDP socket and guarantee that it can be deserialized on the other machine even if the endianness is different. Are there any other "best practices" to perform this functionality given that I have to serialize ints, doubles, floats, and char*?

Answer 1

The portable way: use frexp to serialize (convert to integer mantissa and exponent) and ldexp to deserialize.

The simple way: assume in 2010 any machine you care about uses IEEE float, declare a union with a float element and a uint32_t element, and use your integer serialization code to serialize the float.

The binary-file-haters way: serialize everything as text, floats included. Use the "%a" printf format specifier to get a hex float, which is always expressed exactly (provided you don't limit the precision with something like "%.4a") and not subject to rounding errors. You can read these back with strtod or any of the scanf family of functions.