如何在 udp 服务器（在 c 中）和 udp 客户端（python）之间发送和接收 c 结构？

Question

I have this structure

struct Data
{
      int id;
      int msglen;
      char msg[100];
}

and I need to pass this struct between udp server and udp client.udp client is python based.

Answer 1

First, you need to encode the struct data into a single binary buffer

#include <endian.h>
...
struct Data d { ... };

uint32_t be_id = htobe32(d.id);
uint32_t be_len = htobe32(d.msglen);

size_t pos = 0;
uint8_t buf[sizeof(struct Data)];

memcpy(buf, (const void *)&be_id, sizeof(be_id));
pos += sizeof(be_id);

memcpy(buf + pos, (const void *)&be_len, sizeof(be_len));
pos += sizeof(be_len);

memcpy(buf + pos, (const void *)d.msg, sizeof(d.msg));

Then send the buffer, and parse it from the other side.