[C语言] 16进制整数转字符串

static void hex_to_str(uint8_t *source, uint32_t len, uint8_t *target)
{
    uint8_t ddl, ddh;
    uint32_t i;

    for (i = 0; i < len; i++)
    {
        ddh = ('0' + source[i] / 16);
        ddl = ('0' + source[i] % 16);

        if (ddh > '9')
            ddh = (ddh + ('a' - '9' - 1));
        if (ddl > '9')
            ddl = (ddl + ('a' - '9' - 1));

        target[i * 2] = ddh;
        target[i * 2 + 1] = ddl;
    }
    target[len] = '\0';
}