C++ 如何使用C套接字从客户端到服务器发送和接收整数数组？
问题是：使用TCP和sockets C API从客户机到服务器发送和接收整数数组（稍后是浮点数）。必须同时在Winsock和UNIX中运行 将来可以处理不同的客户端/服务器端，但现在测试是在具有相同端的两台机器（Windows客户端、Linux服务器）之间进行的 我实现了客户机和服务器，这一切似乎都正常工作，但问题在于C++ 如何使用C套接字从客户端到服务器发送和接收整数数组？,c++,arrays,sockets,tcp,C++,Arrays,Sockets,Tcp,问题是：使用TCP和sockets C API从客户机到服务器发送和接收整数数组（稍后是浮点数）。必须同时在Winsock和UNIX中运行 将来可以处理不同的客户端/服务器端，但现在测试是在具有相同端的两台机器（Windows客户端、Linux服务器）之间进行的 我实现了客户机和服务器，这一切似乎都正常工作，但问题在于send（）（客户机）和recv（）（服务器）调用如何处理我的实现方式。或者，换句话说，如果这种方法有缺陷 方法是： 在客户端上，根据预定义的算法生成uint8_t的向量（N个值序
send（）recv（）send（）recv（）recv（）recv（）循环中的文件中recv（）send（）recv（）while (totalBytesRcvd < echoStringLen)
{
bytesRcvd = recv(sock, echoBuffer, RCVBUFSIZE - 1, 0))
totalBytesRcvd += bytesRcvd; /* Keep tally of total bytes */
}
if defined(_MSC_VER)
#include <winsock.h>
#else
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#endif
#include <iostream>
#include <stdint.h>
#include <assert.h>
#include <vector>
const unsigned short server_port = 5000; // server port
void server_echo_text();
void server_recv_data(bool verbose);
void check_file(const uint32_t arr_size, bool verbose, const size_t slab_size);
///////////////////////////////////////////////////////////////////////////////////////
//main
///////////////////////////////////////////////////////////////////////////////////////
int main(int argc, char *argv[])
{
bool verbose = false;
//no arguments
if (argc == 1)
{
server_recv_data(verbose);
}
for (int i = 1; i < argc && argv[i][0] == '-'; i++)
{
switch (argv[i][1])
{
case 'v':
std::cout << "verbose mode: " << std::endl;
verbose = true;
break;
case 'e':
std::cout << "running echo server: " << std::endl;
server_echo_text();
exit(0);
break;
case 'd':
std::cout << "running data server: " << std::endl;
server_recv_data(verbose);
exit(0);
break;
}
}
return 0;
}
///////////////////////////////////////////////////////////////////////////////////////
//server_recv_data
///////////////////////////////////////////////////////////////////////////////////////
void server_recv_data(bool verbose)
{
const int MAXPENDING = 5; // maximum outstanding connection requests
int server_socket; // socket descriptor for server
int client_socket; // socket descriptor for client
sockaddr_in server_addr; // local address
sockaddr_in client_addr; // client address
int recv_size; // size in bytes returned by recv()
#if defined (_MSC_VER)
int len_addr; // length of client address data structure
#else
socklen_t len_addr;
#endif
//data
uint32_t arr_size = 0;
size_t slab_size = 1;
FILE *file;
#if defined (_MSC_VER)
WSADATA ws_data;
if (WSAStartup(MAKEWORD(2, 0), &ws_data) != 0)
{
exit(1);
}
#endif
// create socket for incoming connections
if ((server_socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
exit(1);
}
// construct local address structure
memset(&server_addr, 0, sizeof(server_addr)); // zero out structure
server_addr.sin_family = AF_INET; // internet address family
server_addr.sin_addr.s_addr = htonl(INADDR_ANY); // any incoming interface
server_addr.sin_port = htons(server_port); // local port
// bind to the local address
if (bind(server_socket, (sockaddr*)&server_addr, sizeof(server_addr)) < 0)
{
//bind error: Permission denied
//You're probably trying to bind a port under 1024. These ports usually require root privileges to be bound.
std::cout << "bind error: " << strerror(errno) << std::endl;
exit(1);
}
// mark the socket so it will listen for incoming connections
if (listen(server_socket, MAXPENDING) < 0)
{
exit(1);
}
for (;;) // run forever
{
// set length of client address structure (in-out parameter)
len_addr = sizeof(client_addr);
// wait for a client to connect
if ((client_socket = accept(server_socket, (struct sockaddr *) &client_addr, &len_addr)) < 0)
{
exit(1);
}
// convert IP addresses from a dots-and-number string to a struct in_addr and back
char *str_ip = inet_ntoa(client_addr.sin_addr);
std::cout << "handling client " << str_ip << std::endl;
// receive array size
if ((recv_size = recv(client_socket, (char *)&arr_size, sizeof(uint32_t), 0)) != sizeof(uint32_t))
{
exit(1);
}
std::cout << "server received array size: " << (int)arr_size << std::endl;
//save file
file = fopen("file.bin", "wb");
fwrite(&arr_size, sizeof(uint32_t), 1, file);
//receive array
for (size_t i = 0; i < arr_size; ++i)
{
uint8_t v8;
if ((recv_size = recv(client_socket, (char *)&v8, sizeof(uint8_t), 0)) != sizeof(uint8_t))
{
exit(1);
}
//write 1 element
fwrite(&v8, sizeof(uint8_t), slab_size, file);
}
fclose(file);
std::cout << "server received array: " << std::endl;
check_file(arr_size, verbose, slab_size);
// close client socket
#if defined (_MSC_VER)
closesocket(client_socket);
#else
close(client_socket);
#endif
}
}
///////////////////////////////////////////////////////////////////////////////////////
//check_file
///////////////////////////////////////////////////////////////////////////////////////
void check_file(const uint32_t arr_size, bool verbose, const size_t slab_size)
{
//read file
std::vector<uint8_t> val8(arr_size);
std::vector<uint8_t> val8_c(arr_size);
uint32_t arr_size_r;
uint8_t v8;
FILE *file;
file = fopen("file.bin", "rb");
fread(&arr_size_r, sizeof(uint32_t), 1, file);
assert(arr_size_r == arr_size);
for (size_t i = 0; i < arr_size; ++i)
{
fread(&v8, sizeof(uint8_t), slab_size, file);
val8[i] = v8;
if (verbose) std::cout << (int)val8[i] << " ";
}
if (verbose) std::cout << std::endl;
fclose(file);
//check data, define array the same as in client, compare arrays
v8 = 0;
for (size_t i = 0; i < arr_size; ++i)
{
val8_c[i] = v8;
v8++;
if (v8 == 255)
{
v8 = 0;
}
}
//compare arrays
for (size_t i = 0; i < arr_size; ++i)
{
if (val8_c[i] != val8[i])
{
std::cout << "arrays differ at: " << i << " " << (int)val8_c[i] << " " << (int)val8[i] << std::endl;
assert(0);
}
}
std::cout << "arrays match: " << (int)arr_size << " " << (int)arr_size_r << std::endl;
std::cout << std::endl;
}
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const unsigned short server_port=5000；//服务器端口
void server_echo_text（）；
无效服务器记录数据（bool verbose）；
无效检查文件（const uint32 arr_大小、bool verbose、const size_t slab_大小）；
///////////////////////////////////////////////////////////////////////////////////////
//主要
///////////////////////////////////////////////////////////////////////////////////////
int main（int argc，char*argv[]）
{
bool verbose=false；
//没有争论
如果（argc==1）
{
服务器记录数据（详细）；
}
对于（int i=1；i
我不确定您是否希望发送单个数字，而不是将它们预先封送到一个大的缓冲区中。您将在性能上获得几个数量级的改进。正如@usr所指出的，循环构造得很糟糕。需要的是“全部发送”和“全部接收”函数
这些都是基于史蒂文斯的书《UNIX网络编程：套接字简介》
从客户端发送所有函数和发送函数：
void send_all(int sock, const void *vbuf, size_t size_buf)
{
const char *buf = (char*)vbuf; // can't do pointer arithmetic on void*
int send_size; // size in bytes sent or -1 on error
size_t size_left; // size left to send
const int flags = 0;
size_left = size_buf;
while (size_left > 0)
{
if ((send_size = send(sock, buf, size_left, flags)) == -1)
{
std::cout << "send error: " << strerror(errno) << std::endl;
exit(1);
}
if (send_size == 0)
{
std::cout << "all bytes sent " << std::endl;
break;
}
size_left -= send_size;
buf += send_size;
}
return;
}
///////////////////////////////////////////////////////////////////////////////////////
//client_send_data
///////////////////////////////////////////////////////////////////////////////////////
void client_send_data(const char *server_ip, const uint32_t arr_size_mult)
{
int sock; // socket descriptor
struct sockaddr_in server_addr; // server address
//data
const uint32_t arr_size = arr_size_mult * 255; // array size
//construct array
std::vector<uint8_t> val8(arr_size);
uint8_t v8 = 0;
for (size_t i = 0; i < arr_size; ++i)
{
val8[i] = v8;
v8++;
if (v8 == 255)
{
v8 = 0;
}
}
#if defined (_MSC_VER)
WSADATA ws_data;
if (WSAStartup(MAKEWORD(2, 0), &ws_data) != 0)
{
exit(1);
}
#endif
// create a stream socket using TCP
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
exit(1);
}
// construct the server address structure
memset(&server_addr, 0, sizeof(server_addr)); // zero out structure
server_addr.sin_family = AF_INET; // internet address family
server_addr.sin_addr.s_addr = inet_addr(server_ip); // server IP address
server_addr.sin_port = htons(server_port); // server port
// establish the connection to the server
if (connect(sock, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0)
{
std::cout << "connect error: " << strerror(errno) << std::endl;
exit(1);
}
//send array size
send_all(sock, (void *)&arr_size, sizeof(uint32_t));
std::cout << "client sent array size: " << (int)arr_size << std::endl;
//send array
//std::vector.data() returns the address of the initial element in the container (C++11)
send_all(sock, (void *)val8.data(), sizeof(uint8_t) * val8.size());
std::cout << "client sent array: " << std::endl;
#if defined (_MSC_VER)
closesocket(sock);
WSACleanup();
#else
close(sock);
#endif
}
void send\u all（int sock，const void*vbuf，size\u t size\u buf）
{
const char*buf=（char*）vbuf；//无法在void*
int send_size；//发送的字节大小或错误时为-1
size\u t size\u left；//要发送的剩余大小
const int flags=0；
左尺寸=左尺寸；
而（左侧尺寸>0）
{
如果（（发送大小=发送（sock，buf，size\u left，flags））=-1）
{
std：：coutstd：：cout
闻起来不像C
：）如果您以后考虑使用浮点数（或者更复杂的数据类型组合），您可以考虑使用库将数据结构化为流。Google Protobufs、Cap'n Proto、MAVlink或Apache Thrift可以为您这样做（后两个也在本地支持c）。它们提供了在发送数据之前将数据转换为字节流，并在接收数据之后正确读取数据的有效方法。TCP保证数据将按照在流中发送的顺序发送。但是，对send
和recv
使用单字节缓冲区效率极低。@Andreas Gschossmann.Th这是一个个人项目，主要目标是学习，所以我会尽可能从零开始做每件事，否则就没有乐趣：-）。你是对的，当来到浮动时，这将是一个更大的挑战：-）你假设recv将阅读一条“信息”.TCP不支持消息。该程序将随机失败。
void send_all(int sock, const void *vbuf, size_t size_buf)
{
const char *buf = (char*)vbuf; // can't do pointer arithmetic on void*
int send_size; // size in bytes sent or -1 on error
size_t size_left; // size left to send
const int flags = 0;
size_left = size_buf;
while (size_left > 0)
{
if ((send_size = send(sock, buf, size_left, flags)) == -1)
{
std::cout << "send error: " << strerror(errno) << std::endl;
exit(1);
}
if (send_size == 0)
{
std::cout << "all bytes sent " << std::endl;
break;
}
size_left -= send_size;
buf += send_size;
}
return;
}
///////////////////////////////////////////////////////////////////////////////////////
//client_send_data
///////////////////////////////////////////////////////////////////////////////////////
void client_send_data(const char *server_ip, const uint32_t arr_size_mult)
{
int sock; // socket descriptor
struct sockaddr_in server_addr; // server address
//data
const uint32_t arr_size = arr_size_mult * 255; // array size
//construct array
std::vector<uint8_t> val8(arr_size);
uint8_t v8 = 0;
for (size_t i = 0; i < arr_size; ++i)
{
val8[i] = v8;
v8++;
if (v8 == 255)
{
v8 = 0;
}
}
#if defined (_MSC_VER)
WSADATA ws_data;
if (WSAStartup(MAKEWORD(2, 0), &ws_data) != 0)
{
exit(1);
}
#endif
// create a stream socket using TCP
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
exit(1);
}
// construct the server address structure
memset(&server_addr, 0, sizeof(server_addr)); // zero out structure
server_addr.sin_family = AF_INET; // internet address family
server_addr.sin_addr.s_addr = inet_addr(server_ip); // server IP address
server_addr.sin_port = htons(server_port); // server port
// establish the connection to the server
if (connect(sock, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0)
{
std::cout << "connect error: " << strerror(errno) << std::endl;
exit(1);
}
//send array size
send_all(sock, (void *)&arr_size, sizeof(uint32_t));
std::cout << "client sent array size: " << (int)arr_size << std::endl;
//send array
//std::vector.data() returns the address of the initial element in the container (C++11)
send_all(sock, (void *)val8.data(), sizeof(uint8_t) * val8.size());
std::cout << "client sent array: " << std::endl;
#if defined (_MSC_VER)
closesocket(sock);
WSACleanup();
#else
close(sock);
#endif
}
void recv_all(int sock, void *vbuf, size_t size_buf, FILE *file)
{
char *buf = (char*)vbuf; // can't do pointer arithmetic on void*
int recv_size; // size in bytes received or -1 on error
size_t size_left; // size left to send
const int flags = 0;
size_left = size_buf;
while (size_left > 0)
{
if ((recv_size = recv(sock, buf, size_left, flags)) == -1)
{
std::cout << "recv error: " << strerror(errno) << std::endl;
exit(1);
}
if (recv_size == 0)
{
std::cout << "all bytes received " << std::endl;
break;
}
//save to local file
fwrite(buf, recv_size, 1, file);
size_left -= recv_size;
buf += recv_size;
}
return;
}
///////////////////////////////////////////////////////////////////////////////////////
//server_recv_data
///////////////////////////////////////////////////////////////////////////////////////
void server_recv_data(bool verbose)
{
const int MAXPENDING = 5; // maximum outstanding connection requests
int server_socket; // socket descriptor for server
int client_socket; // socket descriptor for client
sockaddr_in server_addr; // local address
sockaddr_in client_addr; // client address
#if defined (_MSC_VER)
int len_addr; // length of client address data structure
#else
socklen_t len_addr;
#endif
//data
uint32_t arr_size = 0;
const size_t slab_size = 1;
FILE *file;
#if defined (_MSC_VER)
WSADATA ws_data;
if (WSAStartup(MAKEWORD(2, 0), &ws_data) != 0)
{
exit(1);
}
#endif
// create socket for incoming connections
if ((server_socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
exit(1);
}
// construct local address structure
memset(&server_addr, 0, sizeof(server_addr)); // zero out structure
server_addr.sin_family = AF_INET; // internet address family
server_addr.sin_addr.s_addr = htonl(INADDR_ANY); // any incoming interface
server_addr.sin_port = htons(server_port); // local port
// bind to the local address
if (bind(server_socket, (sockaddr*)&server_addr, sizeof(server_addr)) < 0)
{
//bind error: Permission denied
//You're probably trying to bind a port under 1024. These ports usually require root privileges to be bound.
std::cout << "bind error: " << strerror(errno) << std::endl;
exit(1);
}
// mark the socket so it will listen for incoming connections
if (listen(server_socket, MAXPENDING) < 0)
{
exit(1);
}
for (;;) // run forever
{
// set length of client address structure (in-out parameter)
len_addr = sizeof(client_addr);
// wait for a client to connect
if ((client_socket = accept(server_socket, (struct sockaddr *) &client_addr, &len_addr)) < 0)
{
exit(1);
}
// convert IP addresses from a dots-and-number string to a struct in_addr and back
char *str_ip = inet_ntoa(client_addr.sin_addr);
std::cout << "handling client " << str_ip << std::endl;
///////////////////////////////////////////////////////////////////////////////////////
//receive data and save to local file as received
///////////////////////////////////////////////////////////////////////////////////////
//save local file
file = fopen(check_file_name.c_str(), "wb");
//receive/save array size
recv_all(client_socket, &arr_size, sizeof(uint32_t), file);
std::cout << "server received array size: " << (int)arr_size << std::endl;
//receive/save array
uint8_t *buf = new uint8_t[arr_size];
recv_all(client_socket, buf, sizeof(uint8_t) * arr_size, file);
delete[] buf;
fclose(file);
std::cout << "server received array: " << std::endl;
//check
check_file(arr_size, verbose, slab_size);
// close client socket
#if defined (_MSC_VER)
closesocket(client_socket);
#else
close(client_socket);
#endif
}
}