Aakash Bansal Aakash Bansal - 2 months ago 8
C Question

client server communication is not happening. The client code is not displaying after send function

I don't know whether the problem is with the client or with the server or both.This is my first client-server socket programming code. But this is not working as expected. The code which I referenced is working well although.



When the code runs, the client and server should both exchange 2 messages, but they are not doing so. The server is displaying "Listening" which is right as expected but when I run the client code, Nothing happens, It just displays nothing.


This is the client code

#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>

int main() {
struct sockaddr_in mysocket, servsocket;
int err;
char buf[256];



//CREATING SOCKET
int socketstatus = socket(AF_INET, SOCK_STREAM, 0);
printf("%d\n", socketstatus);
if(socketstatus < 0){
printf("socket failed\n");
scanf("%d", &err);
return 0;
}



bzero((char *) &mysocket, sizeof(mysocket));
mysocket.sin_family = AF_INET;
mysocket.sin_addr.s_addr = inet_addr("127.0.0.2");
int port = 5674;
mysocket.sin_port = htons(port);


//CONNECT

int connectstatus = connect(socketstatus, (struct sockaddr *) &servsocket, sizeof(servsocket));
if(connectstatus < 0){
printf("Connect failed\n");
scanf("%d", &err);
return 0;
}

//SEND

bzero(buf, 256);
strcpy(buf, "Message sent by client");
int sendstatus = send(socketstatus, buf, 256, 0);
printf("2\n"); //This is not being displayed
if(sendstatus < 0){
printf("Client send failed\n");
return 0;
}
printf("Reached for receiving\n");
//RECEIVE
bzero(buf, 256);
int recvstatus = recv(socketstatus, buf, 256, 0);
if(recvstatus < 0){
printf("Client RECEIVE failed\n");
scanf("%d", &err);
return 0;
}

printf("The message client got from server is, %s \n",buf );

scanf("%d", &err);

printf("Bye");

}





And this is the server code:

#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
int main() {
int err;
struct sockaddr_in servsocket, clientsocket;
char sendmessage[256];

//CREATING SOCKET
int mysocket = socket(AF_INET, SOCK_STREAM, 0);
if(mysocket < 0){
printf("socket creation failed\n");
scanf("%d", &err);
return 0;
}

bzero((char*) &servsocket, sizeof(servsocket)); //initiazlizing servsocket with null
servsocket.sin_family = AF_INET;
servsocket.sin_addr.s_addr = inet_addr("127.0.0.2");
int port = 5674;
servsocket.sin_port = htons(port);

//BINDING
int bindstatus = bind(mysocket, (struct sockaddr*) &servsocket, sizeof(servsocket));
if(bindstatus < 0){
printf("Socket bind failed\n");
scanf("%d", &err);
return 1;
}

//LISTENING
int listenstatus = listen(mysocket, 5);
if(listenstatus < 0){
scanf("%d", &err);
return 2;
}
else
printf("LISTENING....\n");
//ACCEPTING
int clientsize = sizeof(clientsocket);
int acceptstatus = accept(mysocket, (struct sockaddr*) &clientsocket, &clientsize);
if(acceptstatus < 0){
printf("Accept failed");
scanf("%d", &err);
return 3;
}

char buf[256];
bzero(buf, 256);

//RECEIVING

int recvstatus = recv(acceptstatus, buf, 256, 0);
if(buf < 0){
printf("Error:Nothing read");
scanf("%d", &err);
return 4;
}

printf("I received this message, %s \n", buf);
printf("NOW I WILL SEND\n");

//SENDING
bzero(sendmessage, 256);
strcpy(sendmessage, "Message sent by server");
int sendstatus = send(acceptstatus, sendmessage, sizeof(sendmessage), 0);
if(sendstatus < 0){
printf("Error sending\n");
scanf("%d", &err);
return 5;
}
return 0;
}

Answer

In the client code, you initialize mysocket but pass serversocket to connect uninitialized.

You should be setting the fields of serversocket instead of mysocket.