求助关于局域网 Socket 传送文件时好时坏的问题

硬件背景

Client 树莓派 4B 2G 运行 debian 11 x64 Server Macbook macOS 两者采用有线连接至同一台交换机中

问题表现

在传输文件时有时成功，有时失败。失败时在终端打印乱码，但对于同一文件打印出来的乱码相同，个人猜测是编码问题，但是 debian 和 macOS 用的应该都是 UTF-8 ？而且传字符串没有问题

代码贴图

下面给出 Server 端和 Client 端的代码

//Server 接收端 struct PacketHeader { int size; // 大小：字节 PacketHeader() { size = 0; } }; void *receiveMsg(void *sock) { // system("pwd"); char buffer[1024]; int *socket = (int *) sock; while (1) { usleep(500); int nRecv = recv(*socket, buffer, 1024, 0); if (nRecv <= 0) { continue; } else if (nRecv == sizeof(PacketHeader)) { PacketHeader ph; memcpy(&ph, buffer, nRecv); cout << "大小：" << ph.size << "Bytes" << endl; string filename = ("../Received/" + getCurrentTime() + ".jpg"); FILE *fp = fopen(filename.c_str(), "wb"); if (fp == NULL) { cout << "file not found" << endl; } cout << "开始接收图片" << endl; nRecv = 0; while (nRecv < ph.size) { usleep(500); memset(buffer, 0, sizeof(buffer)); int byteCount = recv(*socket, buffer, 1024, 0); if (byteCount <= 0) { continue; } fwrite(buffer, 1, byteCount, fp); nRecv += byteCount; cout << "已接收 " << nRecv << " Bytes" << endl; } cout << "共接收 " << nRecv << " Bytes" << endl; fclose(fp); } else { buffer[nRecv] = '\0'; cout << buffer << endl; } } 

# Client 发送端 struct PacketHeader { int size; // 大小：字节 PacketHeader() { size = 0; } }; void *sendMsg(void *socket) { int sock = *((int *)socket); while (1) { char msg[4096]; string filename; cin >> filename; FILE *fp = fopen(("../image/" + filename).c_str(), "rb"); if (fp == NULL) { cout << "file not found" << endl; continue; } int sz = FileSize(("../image/" + filename).c_str()); cout << "文件打开成功,大小:" << sz << " Bytes" << endl; PacketHeader ph; ph.size = sz; send(sock, (const char *)&ph, sizeof(ph), 0); cout << "已发送头部信息" << endl; int nSend = 0; char buffer[1024]; while(nSend < sz) { int nBytes = fread(buffer, sizeof(char), sizeof(buffer), fp); if (nBytes <= 0) break; send(sock, buffer, nBytes, 0); cout << "已发送 " << nBytes << " Bytes" << endl; nSend += nBytes; } cout<<"总计发送 "<<nSend<<" Bytes"<<endl; fclose(fp); cout << "successfully send " + filename << endl; } }