C服务器和客户端之间的发送功能不工作
我正在尝试使用send()函数让服务器(SENSORSERVER)和客户端(CGI)进行通信。SENSORSERVER的第一个循环将字符串“Hello world”正确发送给CGI,但在while循环的第二个循环中,CGI无法通过recv功能正确接收 传感器服务器代码C服务器和客户端之间的发送功能不工作,c,multithreading,tcp,send,C,Multithreading,Tcp,Send,我正在尝试使用send()函数让服务器(SENSORSERVER)和客户端(CGI)进行通信。SENSORSERVER的第一个循环将字符串“Hello world”正确发送给CGI,但在while循环的第二个循环中,CGI无法通过recv功能正确接收 传感器服务器代码 int main() { pthread_mutex_init(&mutex, NULL); int welcomeSocket, newSocket; char buffer[1024]; struc
int main() {
pthread_mutex_init(&mutex, NULL);
int welcomeSocket, newSocket;
char buffer[1024];
struct sockaddr_in serverAddr;
struct sockaddr_storage serverStorage;
socklen_t addr_size;
//pthread_create(&t0, NULL ,background(),(void *)"");
//pthread_detach(t0);
//int pthread_join();
pid = fork();
if(pid == -1){
printf("failed to fork");
}
if(pid == 0){
pthread_create(&t0, NULL, background(), (void*)"");
pthread_detach(t0);
} else {
/*---- Create the socket. The three arguments are: ----*/
/* 1) Internet domain 2) Stream socket 3) Default protocol (TCP in this case) */
while(1){
welcomeSocket = socket(PF_INET, SOCK_STREAM, 0);
/*---- Configure settings of the server address struct ----*/
/* Address family = Internet */
serverAddr.sin_family = AF_INET;
/* Set port number, using htons function to use proper byte order */
serverAddr.sin_port = htons(7891);
/* Set IP address to localhost */
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
/* Set all bits of the padding field to 0 */
memset(serverAddr.sin_zero, '\0', sizeof serverAddr.sin_zero);
/*---- Bind the address struct to the socket ----*/
bind(welcomeSocket, (struct sockaddr *) &serverAddr, sizeof(serverAddr));
/*---- Listen on the socket, with 5 max connection requests queued ----*/
if(listen(welcomeSocket, 0) == 0)
printf("Listening\n");
else
printf("Error\n");
/*---- Accept call creates a new socket for the incoming connection ----*/
addr_size = sizeof serverStorage;
newSocket = accept(welcomeSocket, (struct sockaddr *) &serverStorage, &addr_size);
/*---- Send message to the socket of the incoming connection ----*/
int er = pthread_mutex_trylock(&mutex);
if (er == 0)
{
strcpy(buffer,"Hello World\n");
send(newSocket, buffer, sizeof(buffer), 0);
close(newSocket);
close(welcomeSocket);
pthread_mutex_unlock(&mutex);
}
}
}
return EXIT_SUCCESS;
}
和CGI客户端代码
char buf[1024];
char buf2[2024];
int main(void) {
int clientSocket;
char buffer[1024];
struct sockaddr_in serverAddr;
socklen_t addr_size;
/*---- Create the socket. The three arguments are: ----*/
/* 1) Internet domain 2) Stream socket 3) Default protocol (TCP in this case) */
clientSocket = socket(PF_INET, SOCK_STREAM, 0);
/*---- Configure settings of the server address struct ----*/
/* Address family = Internet */
serverAddr.sin_family = AF_INET;
/* Set port number, using htons function to use proper byte order */
serverAddr.sin_port = htons(7891);
/* Set IP address to localhost */
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
/* Set all bits of the padding field to 0 */
memset(serverAddr.sin_zero, '\0', sizeof serverAddr.sin_zero);
/*---- Connect the socket to the server using the address struct ----*/
addr_size = sizeof serverAddr;
connect(clientSocket, (struct sockaddr *) &serverAddr, addr_size);
/*---- Read the message from the server into the buffer ----*/
int er;
er = recv(clientSocket, buffer, sizeof(buffer), 0);
/*---- Print the received message ----*/
printf("Data received: %s",buffer);
//close(clientSocket);
puts("<p>Hello <b>CGI</b</p>");
puts("</BODY>");
puts("</HTML>");
return EXIT_SUCCESS;
}
charbuf[1024];
char buf2[2024];
内部主(空){
int客户端套接字;
字符缓冲区[1024];
serverAddr中的结构sockaddr\u;
袜子尺寸;
/*----创建套接字。三个参数是:----*/
/*1)Internet域2)流套接字3)默认协议(本例中为TCP)*/
clientSocket=socket(PF_INET,SOCK_STREAM,0);
/*----配置服务器地址结构的设置----*/
/*地址家庭=互联网*/
serverAddr.sin_family=AF_INET;
/*设置端口号,使用htons函数使用正确的字节顺序*/
serverAddr.sinu端口=htons(7891);
/*将IP地址设置为本地主机*/
serverAddr.sin_addr.s_addr=inet_addr(“127.0.0.1”);
/*将填充字段的所有位设置为0*/
memset(serverAddr.sin_zero,'\0',serverAddr.sin_zero的大小);
/*----使用地址结构将套接字连接到服务器----*/
地址大小=服务器的大小地址;
连接(clientSocket,(struct sockaddr*)和serverAddr,addr\u size);
/*----将消息从服务器读入缓冲区----*/
内特;
er=recv(clientSocket,buffer,sizeof(buffer),0);
/*----打印收到的消息----*/
printf(“收到的数据:%s”,缓冲区);
//关闭(clientSocket);
( hello cGi问题是您的服务器只接受一个连接(单<代码>接受/代码>调用),然后在发送消息后退出。因此,第二个客户端运行将得到连接失败(在套接字上不再有监听),并打印空白消息(因为您忽略了错误代码)。
如果希望服务器能够处理多个连接,则需要将
accept
调用放入循环中。具体执行方式取决于处理连接的方式。最简单的方法是发送消息,关闭已接受的连接,然后循环:
while (1) { /* infinite loop */
/*---- Accept call creates a new socket for the incoming connection ----*/
addr_size = sizeof serverStorage;
newSocket = accept(welcomeSocket, (struct sockaddr *) &serverStorage, &addr_size);
if (newSocket < 0) {
perror("accept");
break; }
/*---- Send message to the socket of the incoming connection ----*/
int er = pthread_mutex_trylock(&mutex);
if (er == 0) {
strcpy(buffer,"Hello World\n");
send(newSocket, buffer, sizeof(buffer), 0);
close(newSocket);
pthread_mutex_unlock(&mutex);
} else {
/* mutex lock failed (busy?) -- need to do something */
strcpy(buffer,"Error occurred\n");
send(newSocket, buffer, sizeof(buffer), 0);
close(newSocket);
}
}
close(welcomeSocket);
while(1){/*无限循环*/
/*----Accept call为传入连接创建一个新套接字----*/
地址大小=服务器存储的大小;
newSocket=accept(welcomeSocket,(struct sockaddr*)和服务器存储,以及地址大小);
if(newSocket<0){
佩罗(“接受”);
中断;}
/*----将消息发送到传入连接的套接字----*/
int-er=pthread\u mutex\u trylock(&mutex);
如果(er==0){
strcpy(缓冲区,“Hello World\n”);
发送(newSocket,buffer,sizeof(buffer),0);
关闭(newSocket);
pthread_mutex_unlock(&mutex);
}否则{
/*互斥锁失败(忙?)--需要做些什么吗*/
strcpy(缓冲区,“发生错误\n”);
发送(newSocket,buffer,sizeof(buffer),0);
关闭(newSocket);
}
}
关闭(Welcome插座);
如果您想对传入连接执行更复杂的操作,您可能希望分叉一个进程或线程来处理它,而不是直接在循环中执行,因为第二个连接在第一个连接被处理之后才能被接受,并且循环返回到accept调用
Data received:
<p>Hello <b>CGI</b</p>
</BODY>
</HTML>
logout
while (1) { /* infinite loop */
/*---- Accept call creates a new socket for the incoming connection ----*/
addr_size = sizeof serverStorage;
newSocket = accept(welcomeSocket, (struct sockaddr *) &serverStorage, &addr_size);
if (newSocket < 0) {
perror("accept");
break; }
/*---- Send message to the socket of the incoming connection ----*/
int er = pthread_mutex_trylock(&mutex);
if (er == 0) {
strcpy(buffer,"Hello World\n");
send(newSocket, buffer, sizeof(buffer), 0);
close(newSocket);
pthread_mutex_unlock(&mutex);
} else {
/* mutex lock failed (busy?) -- need to do something */
strcpy(buffer,"Error occurred\n");
send(newSocket, buffer, sizeof(buffer), 0);
close(newSocket);
}
}
close(welcomeSocket);