Struct to Bytes and Bytes to Struct

sb_bs.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int pack(void *strct, unsigned char buf[], size_t size) {
	int i = 0;
	unsigned char *byte;
	for (byte = (unsigned char *)strct; size--; ++byte)
		buf[i++] = *byte;

	return 0;
}

#define unpack(strct, buf, size) \
	memcpy(strct, buf, size);

struct test {
	long foo;
	long bar;
};

int main() {
	struct test t = { 5L, 6L };

	unsigned char bytes[sizeof(t)];
	pack(&t, bytes, sizeof(t));

	struct test f;
	unpack(&f, bytes, sizeof(f));

	printf("foo: %lu, bar: %lu\n", f.foo, f.bar);

}