求救，c++写的关于socket的东西
我们老师给了我们一个关于socket的东西，用于客户端和服务器端连接的，作用是先打开服务器端，再打开客户端，客户端输入一个内容然后server端回显出来，以下是代码
server.cpp
// Server.cpp : create a console application, and include the sources in the project
//
// 1. open the *.c in the Visual C++, then "rebuild all".
// 2. click "yes" to create a project workspace.
// 3. You need to -add the library 'ws2_32.lib' to your project
// (Project -> Properties -> Linker -> Input -> Additional Dependencies)
// 4. recompile the source.
#include "stdafx.h"
#include <winsock2.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define DEFAULT_PORT5019
int main(int argc, char **argv){
char szBuff[100];
int msg_len;
int addr_len;
struct sockaddr_in local, client_addr;
SOCKET sock, msg_sock;
WSADATA wsaData;
if (WSAStartup(0x202, &wsaData) == SOCKET_ERROR){
// stderr: standard error are printed to the screen.
fprintf(stderr, "WSAStartup failed with error %d\n", WSAGetLastError());
//WSACleanup function terminates use of the Windows Sockets DLL.
WSACleanup();
return -1;
}
// Fill in the address structure
local.sin_family= AF_INET;
local.sin_addr.s_addr= INADDR_ANY;
local.sin_port= htons(DEFAULT_PORT);
sock = socket(AF_INET,SOCK_STREAM, 0);//TCp socket
if (sock == INVALID_SOCKET){
fprintf(stderr, "socket() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
if (bind(sock, (struct sockaddr *)&local, sizeof(local)) == SOCKET_ERROR){
fprintf(stderr, "bind() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
//waiting for the connections
if (listen(sock, 5) == SOCKET_ERROR){
fprintf(stderr, "listen() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
printf("Waiting for the connections ........\n");
addr_len = sizeof(client_addr);
msg_sock = accept(sock, (struct sockaddr*)&client_addr, &addr_len);
if (msg_sock == INVALID_SOCKET){
fprintf(stderr, "accept() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
printf("accepted connection from %s, port %d\n",
inet_ntoa(client_addr.sin_addr),
htons(client_addr.sin_port));
msg_len = recv(msg_sock, szBuff, sizeof(szBuff), 0);
if (msg_len == SOCKET_ERROR){
fprintf(stderr, "recv() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
if (msg_len == 0){
printf("Client closed connection\n");
closesocket(msg_sock);
return -1;
}
printf("Bytes Received: %d, message: %s from %s\n", msg_len, szBuff, inet_ntoa(client_addr.sin_addr));
msg_len = send(msg_sock, szBuff, sizeof(szBuff), 0);
if (msg_len == 0){
printf("Client closed connection\n");
closesocket(msg_sock);
return -1;
}
closesocket(msg_sock);
WSACleanup();
}
client.cpp
// Client.cpp : Defines the entry point for the console application.
//
// 1. open the *.c in the Visual C++, then "rebuild all".
// 2. click "yes" to create a project workspace.
// 3. You need to -add the library 'ws2_32.lib' to your project
// (Project -> Properties -> Linker -> Input -> Additional Dependencies)
// 4. recompile the source.
#include "stdafx.h"
#include <winsock2.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define DEFAULT_PORT5019
int main(int argc, char **argv){
argc=3;
char szBuff[100];
int msg_len;
//int addr_len;
struct sockaddr_in server_addr;
struct hostent *hp;
SOCKET connect_sock;
WSADATA wsaData;
char*server_name = "localhost";
unsigned shortport = DEFAULT_PORT;
unsigned intaddr;
if (argc != 3){
printf("echoscln [server name] [port number]\n");
return -1;
}
else{
}
if (WSAStartup(0x202, &wsaData) == SOCKET_ERROR){
// stderr: standard error are printed to the screen.
fprintf(stderr, "WSAStartup failed with error %d\n", WSAGetLastError());
//WSACleanup function terminates use of the Windows Sockets DLL.
WSACleanup();
return -1;
}
if (isalpha(server_name[0]))
hp = gethostbyname(server_name);
else{
addr = inet_addr(server_name);
hp = gethostbyaddr((char*)&addr, 4, AF_INET);
}
if (hp==NULL)
{
fprintf(stderr, "Cannot resolve address: %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
//copy the resolved information into the sockaddr_in structure
memset(&server_addr, 0, sizeof(server_addr));
memcpy(&(server_addr.sin_addr), hp->h_addr, hp->h_length);
server_addr.sin_family = hp->h_addrtype;
server_addr.sin_port = htons(port);
connect_sock = socket(AF_INET,SOCK_STREAM, 0);//TCp socket
if (connect_sock == INVALID_SOCKET){
fprintf(stderr, "socket() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
printf("Client connecting to: %s\n", hp->h_name);
if (connect(connect_sock, (struct sockaddr *)&server_addr, sizeof(server_addr))
== SOCKET_ERROR){
fprintf(stderr, "connect() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
printf("input character string:\n");
gets(szBuff);
msg_len = send(connect_sock, szBuff, sizeof(szBuff), 0);
if (msg_len == SOCKET_ERROR){
fprintf(stderr, "send() failed with error %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
if (msg_len == 0){
printf("server closed connection\n");
closesocket(connect_sock);
WSACleanup();
return -1;
}
msg_len = recv(connect_sock, szBuff, sizeof(szBuff), 0);
if (msg_len == SOCKET_ERROR){
fprintf(stderr, "send() failed with error %d\n", WSAGetLastError());
closesocket(connect_sock);
WSACleanup();
return -1;
}
if (msg_len == 0){
printf("server closed connection\n");
closesocket(connect_sock);
WSACleanup();
return -1;
}
printf("Echo from the server %s.\n", szBuff);
closesocket(connect_sock);
WSACleanup();
}
但是运行的时候输入之后两个窗口就自动关掉了，有没有那位高手能说说现在是个什么情况啊，谢谢了？？
[解决办法]
server.cpp // Server.cpp : create a console application, and include the sources in the project // // 1. open the *.c in the Visual C++, then "rebuild all". // 2. click "yes" to create a project workspace. // 3. You need to -add the library 'ws2_32.lib' to your project // (Project -> Properties -> Linker -> Input -> Additional Dependencies) // 4. recompile the source. #include "stdafx.h" #include <winsock2.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #define DEFAULT_PORT 5019 int main(int argc, char **argv){ char szBuff[100]; int msg_len; int addr_len; struct sockaddr_in local, client_addr; SOCKET sock, msg_sock; WSADATA wsaData; if (WSAStartup(0x202, &wsaData) == SOCKET_ERROR){ // stderr: standard error are printed to the screen. fprintf(stderr, "WSAStartup failed with error %d\n", WSAGetLastError()); //WSACleanup function terminates use of the Windows Sockets DLL. WSACleanup(); return -1; } // Fill in the address structure local.sin_family = AF_INET; local.sin_addr.s_addr = INADDR_ANY; local.sin_port = htons(DEFAULT_PORT); sock = socket(AF_INET,SOCK_STREAM, 0); //TCp socket if (sock == INVALID_SOCKET){ fprintf(stderr, "socket() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } if (bind(sock, (struct sockaddr *)&local, sizeof(local)) == SOCKET_ERROR){ fprintf(stderr, "bind() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } //waiting for the connections if (listen(sock, 5) == SOCKET_ERROR){ fprintf(stderr, "listen() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } printf("Waiting for the connections ........\n"); addr_len = sizeof(client_addr); msg_sock = accept(sock, (struct sockaddr*)&client_addr, &addr_len); if (msg_sock == INVALID_SOCKET){ fprintf(stderr, "accept() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } printf("accepted connection from %s, port %d\n", inet_ntoa(client_addr.sin_addr), htons(client_addr.sin_port)); msg_len = recv(msg_sock, szBuff, sizeof(szBuff), 0); if (msg_len == SOCKET_ERROR){ fprintf(stderr, "recv() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } if (msg_len == 0){ printf("Client closed connection\n"); closesocket(msg_sock); return -1; } printf("Bytes Received: %d, message: %s from %s\n", msg_len, szBuff, inet_ntoa(client_addr.sin_addr)); msg_len = send(msg_sock, szBuff, sizeof(szBuff), 0); if (msg_len == 0){ printf("Client closed connection\n"); closesocket(msg_sock); return -1; } closesocket(msg_sock); WSACleanup(); } client.cpp // Client.cpp : Defines the entry point for the console application. // // 1. open the *.c in the Visual C++, then "rebuild all". // 2. click "yes" to create a project workspace. // 3. You need to -add the library 'ws2_32.lib' to your project // (Project -> Properties -> Linker -> Input -> Additional Dependencies) // 4. recompile the source. #include "stdafx.h" #include <winsock2.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #define DEFAULT_PORT 5019 int main(int argc, char **argv){ argc=3; char szBuff[100]; int msg_len; //int addr_len; struct sockaddr_in server_addr; struct hostent *hp; SOCKET connect_sock; WSADATA wsaData; char *server_name = "localhost"; unsigned short port = DEFAULT_PORT; unsigned int addr; if (argc != 3){ printf("echoscln [server name] [port number]\n"); return -1; } else{ } if (WSAStartup(0x202, &wsaData) == SOCKET_ERROR){ // stderr: standard error are printed to the screen. fprintf(stderr, "WSAStartup failed with error %d\n", WSAGetLastError()); //WSACleanup function terminates use of the Windows Sockets DLL. WSACleanup(); return -1; } if (isalpha(server_name[0])) hp = gethostbyname(server_name); else{ addr = inet_addr(server_name); hp = gethostbyaddr((char*)&addr, 4, AF_INET); } if (hp==NULL) { fprintf(stderr, "Cannot resolve address: %d\n", WSAGetLastError()); WSACleanup(); return -1; } //copy the resolved information into the sockaddr_in structure memset(&server_addr, 0, sizeof(server_addr)); memcpy(&(server_addr.sin_addr), hp->h_addr, hp->h_length); server_addr.sin_family = hp->h_addrtype; server_addr.sin_port = htons(port); connect_sock = socket(AF_INET,SOCK_STREAM, 0); //TCp socket if (connect_sock == INVALID_SOCKET){ fprintf(stderr, "socket() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } printf("Client connecting to: %s\n", hp->h_name); if (connect(connect_sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) == SOCKET_ERROR){ fprintf(stderr, "connect() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } printf("input character string:\n"); gets(szBuff); msg_len = send(connect_sock, szBuff, sizeof(szBuff), 0); if (msg_len == SOCKET_ERROR){ fprintf(stderr, "send() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } if (msg_len == 0){ printf("server closed connection\n"); closesocket(connect_sock); WSACleanup(); return -1; } msg_len = recv(connect_sock, szBuff, sizeof(szBuff), 0); if (msg_len == SOCKET_ERROR){ fprintf(stderr, "send() failed with error %d\n", WSAGetLastError()); closesocket(connect_sock); WSACleanup(); return -1; } if (msg_len == 0){ printf("server closed connection\n"); closesocket(connect_sock); WSACleanup(); return -1; } printf("Echo from the server %s.\n", szBuff); closesocket(connect_sock); WSACleanup(); }
[解决办法]
服务器端没有设置 循环接收,
可以在
msg_len = recv(msg_sock, szBuff, sizeof(szBuff), 0);
之前加个while循环
客户端也是发送完了,就直接结束了, 也可以加个while循环
[解决办法]
使用事件等待
[解决办法]
#include "stdafx.h" #include <winsock2.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #define DEFAULT_PORT 5019 int main(int argc, char **argv){ char szBuff[100]; int msg_len; int addr_len; struct sockaddr_in local, client_addr; SOCKET sock, msg_sock; WSADATA wsaData; if (WSAStartup(0x202, &wsaData) == SOCKET_ERROR){ // stderr: standard error are printed to the screen. fprintf(stderr, "WSAStartup failed with error %d\n", WSAGetLastError()); //WSACleanup function terminates use of the Windows Sockets DLL. WSACleanup(); return -1; } // Fill in the address structure local.sin_family = AF_INET; local.sin_addr.s_addr = INADDR_ANY; local.sin_port = htons(DEFAULT_PORT); sock = socket(AF_INET,SOCK_STREAM, 0); //TCp socket if (sock == INVALID_SOCKET){ fprintf(stderr, "socket() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } if (bind(sock, (struct sockaddr *)&local, sizeof(local)) == SOCKET_ERROR){ fprintf(stderr, "bind() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } //waiting for the connections if (listen(sock, 5) == SOCKET_ERROR){ fprintf(stderr, "listen() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } printf("Waiting for the connections ........\n"); addr_len = sizeof(client_addr);while(1){ msg_sock = accept(sock, (struct sockaddr*)&client_addr, &addr_len); if (msg_sock == INVALID_SOCKET){ fprintf(stderr, "accept() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } printf("accepted connection from %s, port %d\n", inet_ntoa(client_addr.sin_addr), htons(client_addr.sin_port)); msg_len = recv(msg_sock, szBuff, sizeof(szBuff), 0); if (msg_len == SOCKET_ERROR){ fprintf(stderr, "recv() failed with error %d\n", WSAGetLastError()); WSACleanup(); return -1; } if (msg_len == 0){ printf("Client closed connection\n"); closesocket(msg_sock); return -1; } printf("Bytes Received: %d, message: %s from %s\n", msg_len, szBuff, inet_ntoa(client_addr.sin_addr)); msg_len = send(msg_sock, szBuff, sizeof(szBuff), 0); if (msg_len == 0){ printf("Client closed connection\n"); closesocket(msg_sock); return -1; } }closesocket(msg_sock); WSACleanup(); }
[解决办法]
服务器端程序时不应该随便退出的，你的这个程序在服务器端accept一次之后，处理完就玩完了。让你的服务器在accept到处理数据放在一个死循环里。客户端随时通讯，服务端随时处理。通知机制就不用了，accept是阻塞的，放在那儿只有当客户连接时才会往下走。
[解决办法]
控制台的代码往往要在末尾加上 getch() 或 system("pause"),
暂停一下
[解决办法]
你的server.cpp中：
在printf("Waiting for the connections ........\n"); 后，如果不想让服务器退出的话,应该这样做：
while (true)
{
msg_sock = accept(sock, (struct sockaddr*)&client_addr, &addr_len);
if (msg_sock == INVALID_SOCKET)
{
fprintf(stderr, "accept() failed with error %d\n", WSAGetLastError());
return -1;
}
//连接成功
//此时用recv接收客户端数据，如果客户端不发送数据，也不关闭，则服务器永远在这里等待
msg_len = recv(msg_sock, szBuff, sizeof(szBuff), 0);
//判断recv是否出错，如果出错，则做异常处理 （我这里就不写了）
//接收完数据后，服务器发送数据。
send(....)
//判断send是否出错，如果出错，则做异常处理 （我这里就不写了）
//关闭客户端连接.再等待客户端连接
closesocket(msg_sock)
}
你这个服务器一个时刻只能处理一个客户端。新手先把这些搞懂后，再去学习处理多个客户端吧。
你这个socket是阻塞式的，后面你可以把它设为非阻塞式的（ioctl 函数），配合select来了解socket