I have a large array of bytes called memory and I'm trying to convert 8 of those bytes to a uint64_t. I'm trying to print the number in big-endian.
I have this so far:
uint64_t value = (uint64_t)(memory[256]) | //location contains byte 88
(uint64_t)(memory[257]) << 8 | //77
(uint64_t)(memory[258]) << 16 | //66
(uint64_t)(memory[259]) << 24 | //55
(uint64_t)(memory[260]) << 32 | //44
(uint64_t)(memory[261]) << 40 | //33
(uint64_t)(memory[262]) << 48 | //22
(uint64_t)(memory[263]) << 56; //11
I print like so:
printf("0x%x", value);
The output is 0x55667788, but I want the output to be 0x1122334455667788.
Any suggestions of how I can fix the above code to print 0x1122334455667788?
The format specifier %lx works because the unsigned long type happens to have at least 64 bits on your system. The C Standard does not guarantee that and indeed it has only 32 bits on 64-bit Microsoft Windows. unsigned long long is guaranteed to have at least 64 bits, so you could use this:
printf("0x%llx\n", (unsigned long long)value);
If your compiler and C library support C99 or a later standard, you can use the macros defined in <inttypes.h>:
printf("0x%" PRIx64 "\n", value);