我想我再次需要帮助..我正在尝试在我的客户端和服务器之间建立连接,如果它成功,用户可以
1) - 输入消息,消息将被发送到服务器 - 服务器会将“我收到你的消息”发回客户端。 - 用户可以输入他/她想要的消息,直到他/她输入“Q”返回主菜单。
2)退出计划。
现在我面临的问题是
1)在1.Input消息 客户端 - 服务器只读取来自客户端输入的第一条消息,之后它不会收到任何消息,而在客户端,它将严格退出程序后退出程序 我的第三个输入以及第二个和第三个输入未发送到服务器。
服务器端 - 服务器一旦传回“我得到你的消息”给客户端 收到了客户的留言。
2)并且我意识到在1.Input消息 当我在第一次输入时按Q时,它将被视为我向服务器发送消息而不是返回主菜单。如果IQ是我的第二或第三个输入,我将什么也不做并将退出程序在我的第三次输入之后
客户端输出(基于我的代码)
Main Menu!
-------------------------
1. Input Message
2. Exit
Enter your choice:
1
Please enter the message :
a
User Input: a
b
User Input: b
c
User Input: c
ron@ron-VirtualBox:~/Desktop/program$ <--exit the program after third input
服务器输出(基于我的代码)
Here is the msg: a <-- only receive first message
现在,如果我重新启动程序并输入Q. 客户端输出(基于我的代码)
Main Menu!
-------------------------
1. Input Message
2. Exit
Enter your choice:
1
Please enter the message :
Q
User Input: Q
Q
User Input: Q
Q
User Input: Q
ron@ron-VirtualBox:~/Desktop/program$ <--exit the program after third input
服务器输出(基于我的代码)
Here is the msg: Q <--treated as a message instead of going to main menu.
预期的客户输出
Main Menu!
-------------------------
1. Input Message
2. Exit
Enter your choice:
1
Please enter the message :
a
User Input: a
I got your msg
b
User Input: b
I got your msg
c
User Input: c
I got your msg
Q
//goes back to Main Menu after pressing Q
Main Menu!
-------------------------
1. Input Message
2. Exit
Enter your choice:
预期的服务器输出
Here is the msg: a
Here is the msg: b
Here is the msg: c
my codes(shown below)
请帮助我,因为我真的很震惊。谢谢你提前
client.cpp
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netdb.h>
#include <stdbool.h>
#include <signal.h>
#include <iostream>
#include <sstream>
void msg(void);
void mainMenu();
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;
bool loop = false;
char options[100];
char buffer[255];
int choice;
char c;
int main(int argc, char *argv[])
{
while(loop==false) {
if (argc < 3) {
fprintf(stderr,"usage %s hostname port\n", argv[0]);
exit(0);
}
portno = atoi(argv[2]);
/* Create a socket point */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
perror("ERROR opening socket");
exit(1);
}
server = gethostbyname(argv[1]);
if (server == NULL) {
fprintf(stderr,"ERROR, no such host\n");
exit(0);
}
bzero((char *)&serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *)server->h_addr,(char *)&serv_addr.sin_addr.s_addr,
server->h_length);
serv_addr.sin_port = htons(portno);
/* connect to the server */
if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0) {
perror("Error connecting");
exit(1);
}
mainMenu();
}
close(sockfd);
return 0;
}
void mainMenu() {
std::cout << "\n" << std::endl;
printf("Main Menu!\n");
printf("-------------------------\n");
printf(" 1. Input Message \n");
printf(" 2. Exit \n");
printf("Enter your choice\n");
scanf("%d",&choice);
getchar();
switch(choice) {
case 1: msg();
break;
case 2: std::cout << "Exiting";
loop = true;
exit(0);
break;
default:printf("%s","Invalid choice!\n");
break;
}
}
void msg(void) {
std::cout << "Press Q to Quit" << std::endl;
std::cout << " " << std::endl;
/*ask for a message from the user, this message will be read by server */
std::cout << "Please enter the message : \n" <<std::endl;
bzero(buffer,256);
while(fgets(buffer,255,stdin)) {
printf("User Input: %s",buffer);
/* Send message to the server */
n = write(sockfd,buffer,strlen(buffer));
if (n < 0) {
perror("ERROR writing to socket");
exit(1);
}
/* read server response */
bzero(buffer,256);
n = read(sockfd,buffer,256);
if (n < 0) {
perror("ERROR reading from socket");
exit(1);
}
if(strncmp(buffer,"Q",1)==0) {
mainMenu();
}
}
}
从我现在所理解的情况来看,它正在导致它现在的输出,因为它停止了 换行后阅读。 所以我需要以某种方式将'\ n'更改为'\ 0'; 我试过这样的东西,但它仍然没有用。
void print() {
size_t length;
std::cout << "Please enter the message: \n" << std::endl;
bzero(buffer,256);
while(fgets(buffer,256,stdin)) {
printf("User Input: %s",buffer);
length = strlen(buffer);
/* Send message to the server */
if(buffer[length - 1] == '\n') {
buffer[length -1] == '\0';
n = write(sockfd,buffer,strlen(buffer));
}
if (n < 0) {
perror("ERROR writing to socket");
exit(1);
}
}
}
答案 0 :(得分:1)
好吧,假设字符串缓冲区包含'Hello \ n \ 0'它的长度(由strlen()返回)是6.要发送此字符串,使用它的换行符和null,您需要发送7个字符,所以n = write(sockfd,buffer,strlen(buffer)+1);