Please help me
client :
#include<stdio.h> //printf
#include<string.h> //strlen
#include<sys/socket.h> //socket
#include<arpa/inet.h> //inet_addr
int main(int argc , char *argv[])
{
int sock;
struct sockaddr_in server;
char message[1000] , server_reply[2000];
//Create socket
sock = socket(AF_INET , SOCK_STREAM , 0);
if (sock == -1)
{
printf("Could not create socket");
}
puts("Socket created");
server.sin_addr.s_addr = inet_addr("127.0.0.1");
server.sin_family = AF_INET;
server.sin_port = htons( 8888 );
//Connect to remote server
if (connect(sock , (struct sockaddr *)&server , sizeof(server)) < 0)
{
perror("connect failed. Error");
return 1;
}
puts("Connected\n");
//keep communicating with server
while(1)
{
printf("Enter message : ");
scanf("%s" , message);
//Send some data
if( send(sock , message , strlen(message) , 0) < 0)
{
puts("Send failed");
return 1;
}
memset(message,0,sizeof(message));
//Receive a reply from the server
}
close(sock);
return 0;
}
server:
#include<stdio.h>
#include<string.h> //strlen
#include<sys/socket.h>
#include<arpa/inet.h> //inet_addr
#include<unistd.h> //write
int main(int argc , char *argv[])
{
int socket_desc , client_sock , c , read_size;
struct sockaddr_in server , client;
char client_message[2000];
//Create socket
socket_desc = socket(AF_INET , SOCK_STREAM , 0);
if (socket_desc == -1)
{
printf("Could not create socket");
}
puts("Socket created");
//Prepare the sockaddr_in structure
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons( 8888 );
//Bind
if( bind(socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
{
//print the error message
perror("bind failed. Error");
return 1;
}
puts("bind done");
//Listen
listen(socket_desc , 3);
//Accept and incoming connection
puts("Waiting for incoming connections...");
c = sizeof(struct sockaddr_in);
//accept connection from an incoming client
client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c);
if (client_sock < 0)
{
perror("accept failed");
return 1;
}
puts("Connection accepted");
//Receive a message from client
while( (read_size = recv(client_sock , client_message , 2000 , 0)) > 0 )
{
if(read_size == 0)
{
puts("Client disconnected");
fflush(stdout);
}
else if(read_size == -1)
{
perror("recv failed");
}
//Send the message back to client
puts(client_message);
fflush(stdout);
}
return 0;
}
It's source code from a site. I try it and success connect and send message. Problem is when I connect client to server. Then I close server with ctrl + c. I try to send message, why my message send successfully? (when server over). But when I try send message again, connection over. Please help me. I want to only once send, connection over. Not twice.
What happens is this: Your code exits because a SIG_PIPE is raised to indicate a send error. You do not have a signal catcher therefore the default action is to exit,silently!
Try this send(sock , message , strlen(message) ,MSG_NOSIGNAL)
and read on signals
but how only once send, connection over (server close with ctrl + c)? not twice send.
While you have no recv()
call in your client, you can still detect the Broken pipe immediately after the first send()
call following the server termination by getting the pending socket error with getsockopt(…, SOL_SOCKET, SO_ERROR, …)
, as shown for example in this answer to "How to find the socket connection state in C?"
If an error is returned that way, you can break
your loop and close()
the socket.
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