C++ 客户端到服务器发送字符串消息c++；
我有一个服务器和一个客户端，我正试图将一条消息作为字符串从客户端发送到服务器。我成功地这样做了一次，但当我尝试发送另一个字符串时，我收到错误：C++ 客户端到服务器发送字符串消息c++；,c++,sockets,server,client,C++,Sockets,Server,Client,我有一个服务器和一个客户端，我正试图将一条消息作为字符串从客户端发送到服务器。我成功地这样做了一次，但当我尝试发送另一个字符串时，我收到错误：client:connect error:Transport endpoint已连接 -----如何编译----- -----如何执行----- /server.x /client.x 执行两个文件后，将显示以下选项： ----------选择权---------- 服务器-向服务器发送命令 退出-退出程序 如果键入“服务器”，将显示以下选项： ----
client:connect error:Transport endpoint已连接/server.x
/client.x
int main() {
int sockid, newsd;
struct sockaddr_in my_addr, client_addr;
socklen_t clilen = sizeof(client_addr);
thread cmd;
cout << "Server creating socket.\n";
if( (sockid = socket(AF_INET,SOCK_STREAM,0)) < 0) {
cout << "Socket Error.\n";
exit(0);
}
cout << "Server binding my local socket.\n";
bzero((char *) &my_addr,sizeof(my_addr));
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(MY_PORT_ID);
my_addr.sin_addr.s_addr = htons(INADDR_ANY);
if( bind(sockid ,(struct sockaddr *) &my_addr,sizeof(my_addr)) < 0 ) {
cout << "Bind error.\n";
exit(0);
}
cout << "Server starting listen.\n";
if( listen(sockid,5) < 0 ) {
cout << "Listen error.\n";
exit(0);
}
cout << "Server running...listening for connections.\n";
for( ; ; ) {
cout << "Server starting accept.\n";
cout << "newd: " << newsd << endl;
cout << "sockid: " << sockid << endl;
cout << "client_addr: " << &client_addr << endl;
cout << "clilen: " << clilen << endl;
if ((newsd = accept(sockid ,(struct sockaddr *) &client_addr, &clilen)) < 0) {
perror( "Failed to accept." );
exit(0);
}
cout << "newsd: " << newsd << endl;
cout << "Server return from accept, socket for this ftp: "<< newsd << endl;
// close(sockid); /* child shouldn't do an accept */
thread cmd ( receiveCommand, newsd );
//cmd.detach();
//cmd.join();
// close (newsd);
// exit(0); /* child all done with work */
}
// cmd.join();
/* Parent continues below here */
close(newsd); /* parent all done with client, only child */
close(sockid);
return 0;
}
void receiveCommand(int newsd)
{
string cmd;
int msg_ok,fail,req,tmp;
char command[MAXLINE], commandSize = 0;
req = 0;
if((readn(newsd,(char *)&req,sizeof(req))) < 0) {
perror( "Read error" );
exit(0);
}
req = ntohs(req);
cout << "Client request code is: " << req << endl;
if (req!=REQUESTCOMMAND) {
cout << "Unsupported operation. goodbye\n";
/* reply to client: command not OK (code: 150) */
msg_ok = COMMANDNOTSUPPORTED;
msg_ok = htons(msg_ok);
if((writen(newsd,(char *)&msg_ok,sizeof(msg_ok))) < 0 ) {
perror( "Write error." );
exit(0);
}
exit(0);
}
/* reply to client: command OK (code: 160) */
msg_ok = COMMANDSUPPORTED;
msg_ok = htons(msg_ok);
if( writen(newsd,(char *)&msg_ok,sizeof(msg_ok)) < 0 ) {
perror( "Write error.");
exit(0);
}
fail = COMMANDOK;
if( (commandSize = read(newsd,command,MAXLINE)) < 0 ) {
perror("Command read error." );
fail = BADCOMMAND ;
}
command[commandSize] = '\0';
tmp = htons(fail);
if( (writen(newsd,(char *)&tmp,sizeof(tmp))) < 0 ) {
perror("Write error" );
exit(0);
}
if(fail == BADCOMMAND) {
cout << "Server cant do command.\n";
close(newsd);
exit(0);
}
cout << "Command is: " << command << endl;
if( command == "gbye"){
cout << endl;
cout << "Client requested server to shutdown...\n";
cout << "Goodbye.\n";
exit( 0 );
}
else{
cout << "Command TRANSFER COMPLETE on socket " << newsd << endl;
}
close(newsd);
}
/*
To take care of the possibility of buffer limmits in the kernel for the
socket being reached (which may cause read or write to return fewer characters
than requested), we use the following two functions */
int readn(int sd,char *ptr,int size)
{
int no_left,no_read;
no_left = size;
while (no_left > 0) {
no_read = read(sd,ptr,no_left);
if(no_read <0) return(no_read);
if (no_read == 0) break;
no_left -= no_read;
ptr += no_read;
}
return(size - no_left);
}
int writen(int sd,char *ptr,int size)
{ int no_left,no_written;
no_left = size;
while (no_left > 0) {
no_written = write(sd,ptr,no_left);
if(no_written <=0) return(no_written);
no_left -= no_written;
ptr += no_written;
}
return(size - no_left);
}
intmain（）{
int sockid，newsd；
我的地址、客户地址中的结构sockaddr\u；
socklen\u t clilen=sizeof（客户地址）；
线程cmd；
cout您的客户端代码出现错误-您正在调用connect（）（true）循环而不需要它-一旦您的客户端连接，在连接终止和套接字关闭之前，它不需要再次执行此操作。您是否在同一台机器上同时运行多个客户端或服务器？在同一台机器上只运行一个客户端和一个服务器@Nathantuggy在连接之前绑定客户端套接字是正确的没有必要，可能是个坏主意。
./server.x
./client.x <IP Address>
int main() {
int sockid, newsd;
struct sockaddr_in my_addr, client_addr;
socklen_t clilen = sizeof(client_addr);
thread cmd;
cout << "Server creating socket.\n";
if( (sockid = socket(AF_INET,SOCK_STREAM,0)) < 0) {
cout << "Socket Error.\n";
exit(0);
}
cout << "Server binding my local socket.\n";
bzero((char *) &my_addr,sizeof(my_addr));
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(MY_PORT_ID);
my_addr.sin_addr.s_addr = htons(INADDR_ANY);
if( bind(sockid ,(struct sockaddr *) &my_addr,sizeof(my_addr)) < 0 ) {
cout << "Bind error.\n";
exit(0);
}
cout << "Server starting listen.\n";
if( listen(sockid,5) < 0 ) {
cout << "Listen error.\n";
exit(0);
}
cout << "Server running...listening for connections.\n";
for( ; ; ) {
cout << "Server starting accept.\n";
cout << "newd: " << newsd << endl;
cout << "sockid: " << sockid << endl;
cout << "client_addr: " << &client_addr << endl;
cout << "clilen: " << clilen << endl;
if ((newsd = accept(sockid ,(struct sockaddr *) &client_addr, &clilen)) < 0) {
perror( "Failed to accept." );
exit(0);
}
cout << "newsd: " << newsd << endl;
cout << "Server return from accept, socket for this ftp: "<< newsd << endl;
// close(sockid); /* child shouldn't do an accept */
thread cmd ( receiveCommand, newsd );
//cmd.detach();
//cmd.join();
// close (newsd);
// exit(0); /* child all done with work */
}
// cmd.join();
/* Parent continues below here */
close(newsd); /* parent all done with client, only child */
close(sockid);
return 0;
}
void receiveCommand(int newsd)
{
string cmd;
int msg_ok,fail,req,tmp;
char command[MAXLINE], commandSize = 0;
req = 0;
if((readn(newsd,(char *)&req,sizeof(req))) < 0) {
perror( "Read error" );
exit(0);
}
req = ntohs(req);
cout << "Client request code is: " << req << endl;
if (req!=REQUESTCOMMAND) {
cout << "Unsupported operation. goodbye\n";
/* reply to client: command not OK (code: 150) */
msg_ok = COMMANDNOTSUPPORTED;
msg_ok = htons(msg_ok);
if((writen(newsd,(char *)&msg_ok,sizeof(msg_ok))) < 0 ) {
perror( "Write error." );
exit(0);
}
exit(0);
}
/* reply to client: command OK (code: 160) */
msg_ok = COMMANDSUPPORTED;
msg_ok = htons(msg_ok);
if( writen(newsd,(char *)&msg_ok,sizeof(msg_ok)) < 0 ) {
perror( "Write error.");
exit(0);
}
fail = COMMANDOK;
if( (commandSize = read(newsd,command,MAXLINE)) < 0 ) {
perror("Command read error." );
fail = BADCOMMAND ;
}
command[commandSize] = '\0';
tmp = htons(fail);
if( (writen(newsd,(char *)&tmp,sizeof(tmp))) < 0 ) {
perror("Write error" );
exit(0);
}
if(fail == BADCOMMAND) {
cout << "Server cant do command.\n";
close(newsd);
exit(0);
}
cout << "Command is: " << command << endl;
if( command == "gbye"){
cout << endl;
cout << "Client requested server to shutdown...\n";
cout << "Goodbye.\n";
exit( 0 );
}
else{
cout << "Command TRANSFER COMPLETE on socket " << newsd << endl;
}
close(newsd);
}
/*
To take care of the possibility of buffer limmits in the kernel for the
socket being reached (which may cause read or write to return fewer characters
than requested), we use the following two functions */
int readn(int sd,char *ptr,int size)
{
int no_left,no_read;
no_left = size;
while (no_left > 0) {
no_read = read(sd,ptr,no_left);
if(no_read <0) return(no_read);
if (no_read == 0) break;
no_left -= no_read;
ptr += no_read;
}
return(size - no_left);
}
int writen(int sd,char *ptr,int size)
{ int no_left,no_written;
no_left = size;
while (no_left > 0) {
no_written = write(sd,ptr,no_left);
if(no_written <=0) return(no_written);
no_left -= no_written;
ptr += no_written;
}
return(size - no_left);
}
int main(int argc,char *argv[])
{
int sockid, newsd, portNum, clientportNum, serverportNum;
struct sockaddr_in my_addr, server_addr;
if( argc != 2 ) {
cout << "Error: Usage : IP-dotted-notation \n", argv[0];
exit(0);
}
if( (sockid = socket(AF_INET,SOCK_STREAM,0)) < 0 ) {
cout << "Client Socket Error.\n";
exit(0);
}
clientportNum = 8000;
serverportNum = 8001;
cout << "Client Binding My Local Socket\n";
bzero((char *) &my_addr, sizeof(my_addr));
my_addr.sin_family = AF_INET;
my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
my_addr.sin_port = htons(clientportNum);
if( bind(sockid ,(struct sockaddr *) &my_addr,sizeof(my_addr)) < 0 ){
cout << "Client Bind Error.\n";
exit(0);
}
cout << "Client Starting Connect\n";
bzero((char *) &server_addr,sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = inet_addr(argv[1]);
server_addr.sin_port = htons(serverportNum);
while( 1 ){
string cmd_option;
cout << endl;
cout << "---------- Options ----------\n";
cout << "server - send a command to the server\n";
cout << "exit - exit program\n";
cout << endl;
cout << "~: ";
getline(cin, cmd_option);
if( cmd_option == "server" ){
// *****Error Here*****
if( connect(sockid ,(struct sockaddr *) &server_addr, sizeof(server_addr)) < 0 ) {
//cout << "Client Connect Error.\n";
printf("client: connect error :%s\n", strerror( errno ));
exit(0);
}
giveServerCommand(sockid);
}
else if( cmd_option == "exit" ){
cout << endl;
cout << "Exiting program...\n";
cout << "Goodbye.\n";
exit(0);
}
else{
cout << "Invalid Command.\n";
}
}
}
void giveServerCommand(int sockid)
{
string user_input;
// User Interface
cout << "\n-----Server Command Options:-----\n";
cout << "m - send message to server\n";
cout << "\n";
cout << "~: ";
getline(cin, user_input);
if ( user_input == "m" ){
string buffer;
cout << "\nType a command to the server: ";
getline( cin, buffer );
cout << "You typed: " << buffer << endl;
int getcommand,msg,msg_2,len;
len = buffer.size();
getcommand = htons(REQUESTCOMMAND);
cout << "Client sending command request to server.\n";
int n = 0;
if( n = (writen(sockid,(char *)&getcommand,sizeof(getcommand))) < 0 ) {
cout << "Client write error: " << n << endl;
exit(0);
}
/* want for go-ahead from server */
cout << "command: " << getcommand << endl;
cout << "sockid: " << sockid << endl;
cout << "msg: " << &msg << endl;
cout << "msg size: " << sizeof(msg) << endl;
msg = 0;
if((readn(sockid,(char *)&msg,sizeof(msg)))< 0) {
cout << "Client read error.\n";
exit(0);
}
cout << "msg: " << msg << endl;
msg = ntohs(msg);
cout << "msg after ntohs: " << msg << endl;
if (msg==COMMANDNOTSUPPORTED) {
cout << "Server refused command. Goodbye...\n";
cout << endl;
exit(0);
}
else
cout << "Server replied, command supported.\n";
/* send command to server */
cout << "Client sending command.\n";
cout << "sockid: " << sockid << endl;
cout << "buffer: " << buffer.c_str() << endl;
cout << "len: " << len << endl;
if ((writen(sockid, (char *) buffer.c_str(),len)) < 0) {
cout << "Client write error.\n";
exit(0);
}
/* see if server replied that command is OK */
cout << "sockid: " << sockid << endl;
cout << "msg2: " << &msg_2 << endl;
cout << "msg2 size: " << sizeof(msg_2) << endl;
msg_2 = 0;
if (readn(sockid, (char *)&msg_2, sizeof(msg_2)) < 0) {
cout << "Client read error: %s\n", strerror( errno );
exit(0);
}
cout << "msg2 before ntohs: " << msg_2 << endl;
msg_2 = ntohs(msg_2);
cout << "msg2 after ntohs: " << msg_2 << endl;
if (msg_2 == BADCOMMAND) {
cout << "Server reported bad command. Goodbye...\n";
exit(0);
}
else
cout << "Server replied, Command OK.\n";
/*Command transfer ends. client terminates after closing all its sockets*/
cout << "COMMAND TRANSFER COMPLETE\n";
}
else{
cout << "\nInvalid Option.\n";
}
}
int readn(int sd, char *ptr, int size)
{
int no_left,no_read;
cout << "-----Within readn function------" << endl;
cout << "sd: " << sd << endl;
cout << "char ptr: " << &ptr << endl;
cout << "size: " << size << endl;
no_left = size;
while (no_left > 0) {
no_read = read(sd,ptr,no_left);
cout << "no_read: " << no_read << endl;
if(no_read <0) return(no_read);
if (no_read == 0) break;
no_left -= no_read;
ptr += no_read;
}
cout << "size - no_left: " << size - no_left << endl;
cout << "--------------------------------" << endl;
return(size - no_left);
}
int writen(int sd,char *ptr,int size)
{
/*
cout << "-----Within writen function------" << endl;
cout << "sd: " << sd << endl;
cout << "char ptr: " << &ptr << endl;
cout << "size: " << size << endl;
*/
int no_left,no_written;
no_left = size;
while (no_left > 0) {
no_written = write(sd,ptr,no_left);
//cout << "no_written: " << no_written << endl;
if(no_written <=0) return(no_written);
no_left -= no_written;
ptr += no_written;
}
/*
cout << "size - no_left: " << size - no_left << endl;
cout << "--------------------------------" << endl;
*/
return(size - no_left);
}