Write an unsigned big-endian 16-bit integer
#include <uint16.h>
uint16 u;
void uint16_pack_big(char s[2],uint16 u);
uint16 is a 16-bit unsigned integer type, normally either unsigned int or unsigned long.
uint16_pack_big portably writes a uint16 u to s in big-endian (i.e. network) byte order.