我正在做一個小型的客戶端 - 服務器應用程序,其中服務器在接受之後分叉一個子進程,在客戶端連接到它時進行多個連接,發送消息並接收響應。以下是我的代碼片段: - client.c在TCP套接字連接期間通過對端重置連接?
char buffer [256];
portno=5001;
/* Create a socket point */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
perror("ERROR opening socket");
exit(1);
}
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(portno);
/* Now connect to the server */
if (connect(sockfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) < 0) {
perror("ERROR connecting");
exit(1);
}
/* Now ask for a message from the user, this message
* will be read by server
*/
while(1)
{
printf("Please enter the message: ");
bzero(buffer,256);
fgets(buffer,255,stdin);
/* Send message to the server */
n = write(sockfd, buffer, strlen(buffer));
if (n < 0) {
perror("ERROR writing to socket");
exit(1);
}
/* Now read server response */
bzero(buffer,256);
n = read(sockfd, buffer, 255);
if(n==0)
{
perror("nothing to read");
}
if (n < 0) {
perror("ERROR reading from socket");
exit(1);
}
printf("%s\n",buffer);
}
--server.c
int main(int argc, char *argv[]) {
int sockfd, newsockfd, portno, clilen;
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n, pid;
/* First call to socket() function */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
perror("ERROR opening socket");
exit(1);
}
/* Initialize socket structure */
bzero((char *) &serv_addr, sizeof(serv_addr));
portno = 5001;
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(portno);
/* Now bind the host address using bind() call.*/
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
perror("ERROR on binding");
exit(1);
}
/* Now start listening for the clients, here
* process will go in sleep mode and will wait
* for the incoming connection
*/
listen(sockfd,5);
clilen = sizeof(cli_addr);
while (1) {
newsockfd = accept(sockfd, (struct sockaddr *)NULL,NULL);
if (newsockfd < 0) {
perror("ERROR on accept");
exit(1);
}
/* Create child process */
pid = fork();
if (pid < 0) {
perror("ERROR on fork");
exit(1);
}
if (pid == 0)
{
while(1)
{
/* This is the client process */
close(sockfd);
doprocessing(newsockfd);
/** exit(0); **/
}
}
else {
close(newsockfd);
}
} /* end of while */
}
void doprocessing (int sock) {
int n;
char buffer[256];
bzero(buffer,256);
n = read(sock,buffer,255);
if(n==0)
{
perror("nothing to read");
}
if (n < 0) {
perror("ERROR reading from socket");
exit(1);
}
printf("Here is the message: %s\n",buffer);
n = write(sock,"I got your message",18);
if (n <= 0) {
perror("ERROR writing to socket");
exit(1);
}
}
當我運行兩個,O/P是繼
:
Please enter the message: arjun
I got your message
Please enter the message: gaur
ERROR reading from socket: Connection reset by peer
請help.how解決這個
您還沒有關閉套接字在派生的子進程,你不檢查的recv的'()'零的返回值。 – EJP
那麼接近(sockfd)裏面的子進程在幹什麼?我處理recv()= 0,但它不是打印裏面的語句。我編輯了代碼。 –
'close(sockfd)'正在關閉偵聽套接字。分叉的孩子沒有關閉接受的套接字('newsockfd')。您不會在此分叉的子進程或客戶端中處理'n == 0',除非將其錯誤地視爲服務器的分叉子進程中的錯誤。 – EJP