超强数值进制转换，纯Ｃ代码 .

01.#define pj_hex_digits   "0123456789abcdef"
02.void pj_val_to_hex_digit(unsigned value, char *p) //十进制转成16进制
03.{
04.    *p++ = pj_hex_digits[ (value & 0xF0) >> 4 ];
05.    *p   = pj_hex_digits[ (value & 0x0F) ];
06.}