16进制整数转化成字符串

    Linux下gcc没有itoa，项目要用到16位地址转换成字符通过串口发送，只能自己动手
                              

int itoa(int val, char *buf,int size) const//16进制{    char *p = buf;    char t = '0';    int len = 0;    int slen = size;    while(val > 0 && len < slen) {        t = val % 16;        val -= t;        val /= 16;        if (t > 9) {            *p++ = t- 10 + 'a';        } else {            *p++ = t + '0';        }        ++len;    }    for (int i = 0;i < len/2;++i) {        char c = buf[i];        buf[i] = buf[len-1-i];        buf[len-1-i] = c;    }    buf[len] = '\0';    return len;}