将字符串包读入数组然后解析

Question

所以，首先，我为此成为一个新手而道歉。我试图自己解决这个问题并搜索其他答案，但我甚至不确定究竟要搜索什么。我发现this是一个有用的答案，但只是希望得到一些更多的澄清。

我正在与几个开发板工作，试图让他们互相交谈。我需要与之交谈的一块板子给出了一些我一直试图使用的示例代码。 TX函数工作正常，我对C不够熟悉，无法完全理解我在做什么。

他们提供的RX功能是：

int recv_packet(char *p, int len){
    char c;
    int received = 0;
    /* sit in a loop reading bytes until we put together
    * a whole packet.
    * Make sure not to copy them into the packet if we
    * run out of room.
    */
    while(1) {
        /* get a character to process
        */
        c = UART_GetChar();
        /* handle bytestuffing if necessary
        */
        switch(c) {
            /* if it's an END character then we're done with
            * the packet
            */
            case END:
                /* a minor optimization: if there is no
                * data in the packet, ignore it. This is
                * meant to avoid bothering IP with all
                * the empty packets generated by the
                * duplicate END characters which are in
                * turn sent to try to detect line noise.
                */
                if(received)
                    return received;
                else
                    break;
            /* if it's the same code as an ESC character, wait
            * and get another character and then figure out
            * what to store in the packet based on that.
            */
            case ESC:
                c = UART_GetChar();
                /* if "c" is not one of these two, then we
                * have a protocol violation. The best bet
                * seems to be to leave the byte alone and
                * just stuff it into the packet
                */
                switch(c) {
                    case ESC_END:
                        c = END;
                        break;
                    case ESC_ESC:
                        c = ESC;
                        break;
                }
            /* here we fall into the default handler and let
            * it store the character for us
            */
            default:
                if(received < len)
                p[received++] = c;
        }
    }
}

然后基于我发现的答案，我可以用类似的功能调用它

int main() {
    char arr[10] = {0};
    recv_packet(arr, 10);
    /*then parse it somehow-- 
    * I'll figure this out on my own, 
    * but for now I just want to read it all 
    * into an array.
    */
    parse_function(arr);
}

所以，如果你完成了所有这些....我的一个大问题是，如果我的长度小于我需要接收的消息，我该如何阻止我的阵列填满？我正在使用C与之交谈的设备将发送回一系列以0xC0开头和结尾的十六进制字符（否则在其他代码中定义为'END'）但中间是一整套十六进制，这是一个回复来自设备取决于我在send_packet中发送的内容。我想我可以让arr非常大以防万一，但我想知道在这种情况下适当的编码会有什么作用。

Answer 1

另一答案