Java bytebuffer to C

Question

Hello,

From a C program on Windows we need to read and write like a Java bytebuffer which stores binary in BIG_ENDIAN

The algorithm is described at : http://mindprod.com/jgloss/binaryformats.html

Need to read and write int and float.

Does anyone have example c or C++ code that does this or a reference ?

TIA, Bert

Answer 1

I assume the difficulty is in converting between Big Endian and Little Endian.

This article should help you out with the Endian conversions. It contains code to swap the byte order on integers, long integers, floating point numbers, and byte arrays of arbitrary length.
http://www.codeproject.com/KB/cpp/endianness.aspx

The code to swap an arbitrary type looks like this:

#include <algorithm> //required for std::swap

#define ByteSwap5(x) ByteSwap((unsigned char *) &x,sizeof(x))

void ByteSwap(unsigned char * b, int n)
{
   register int i = 0;
   register int j = n-1;
   while (i<j)
   {
      std::swap(b[i], b[j]);
      i++, j--;
   }
}

Answer 2

You want to use htonl and similar. The rest of design is your own.