Assuming what you need is a simple byte swap, try something like Unsigned 16 bit conversion: swapped = (num>>8) | (num<<8); Unsigned 32-bit conversion: swapped = ((num>>24)&0xff) | // move byte 3 to byte 0 ((num<<8)&0xff0000) | // move byte 1 to byte 2 ((num>>8)&0xff00) | // move byte 2 to byte 1 ((num<<24)&0xff000000); // … Read more
Code supporting arbitrary byte orders, ready to be put into a file called order32.h: #ifndef ORDER32_H #define ORDER32_H #include <limits.h> #include <stdint.h> #if CHAR_BIT != 8 #error “unsupported char size” #endif enum { O32_LITTLE_ENDIAN = 0x03020100ul, O32_BIG_ENDIAN = 0x00010203ul, O32_PDP_ENDIAN = 0x01000302ul, /* DEC PDP-11 (aka ENDIAN_LITTLE_WORD) */ O32_HONEYWELL_ENDIAN = 0x02030001ul /* Honeywell 316 (aka … Read more
Use the classes found in the java.nio namespace, in particular, the ByteBuffer. It can do all the work for you. byte[] arr = { 0x00, 0x01 }; ByteBuffer wrapped = ByteBuffer.wrap(arr); // big-endian by default short num = wrapped.getShort(); // 1 ByteBuffer dbuf = ByteBuffer.allocate(2); dbuf.putShort(num); byte[] bytes = dbuf.array(); // { 0, 1 }
Endianness is the way values are stored in memory. When loaded into the processor, regardless of endianness, the bit shift instruction is operating on the value in the processor’s register. Therefore, loading from memory to processor is the equivalent of converting to big endian, the shifting operation comes next and then the new value is … Read more
I don’t like the method based on type punning – it will often be warned against by compiler. That’s exactly what unions are for! bool is_big_endian(void) { union { uint32_t i; char c[4]; } bint = {0x01020304}; return bint.c[0] == 1; } The principle is equivalent to the type case as suggested by others, but … Read more
If you’re using Visual C++ do the following: You include intrin.h and call the following functions: For 16 bit numbers: unsigned short _byteswap_ushort(unsigned short value); For 32 bit numbers: unsigned long _byteswap_ulong(unsigned long value); For 64 bit numbers: unsigned __int64 _byteswap_uint64(unsigned __int64 value); 8 bit numbers (chars) don’t need to be converted. Also these are … Read more