server.cpp

cplusplus socket programming ,easy , single connection

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



int main()
{
	// Create a socket 
	cout << "To create socket" << endl;
	int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) 
	{ 
		cout << "socket creation"; return -1; 
	}

	int port = 5010;
	struct sockaddr_in sin;
        
    //sin.sin_len = sizeof(sin);
	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = htonl(INADDR_ANY);
	sin.sin_port = htons(port);
        
    //bind sin to socket
	cout << "To bind: " << sock << endl;
	int rt1 = bind(sock, (sockaddr * )&sin, sizeof(sin));
    if (rt1 < 0) 
	{ 
		cout << "********** Failed to bind: " << rt1 << endl;
		return -1;
	}
        
    //listening to the port
	cout << "Bind successful, to listen!" << endl;
	int rt2 = listen(sock, 3);
    if (rt2 < 0) 
	{ 
		cout << "*************Listening error!";
	}

	cout << "Listen success: " << rt2 << endl;
	struct sockaddr_in cli_addr;
    socklen_t clilen = sizeof(cli_addr);
    memset((char *) &cli_addr, 0, sizeof(cli_addr));

	cout << "To accept new connection" << endl;
    int newSock = accept(sock, (struct sockaddr *) &cli_addr, &clilen);

    if (newSock < 0)
    {
		cout << "********** Failed to accept: " << newSock << endl;
        return 0;
    }

	cout << "Accepted a new sock: " << newSock << endl;

	char buff[10000];
	int len;
	while (1)
	{
		len = 10000;
		fd_set readFD;
		FD_ZERO(&readFD);

		// FD_SET(newSock, &readFD);
		int ret = select(newSock+1, &readFD, 0, 0, 0);

		cout << "select returned: " << ret << endl;
		if (ret < 0)
		{
			cout << "********** Failed to select: " << ret << endl;
			continue;
		}

		if (FD_ISSET(newSock, &readFD))
		{
			len = read(newSock, buff, len);
			if (len == 0)
			{
				cout << "End of File read" << endl;
				close(newSock);
				close(sock);
				return -1;
			}
		
			cout << "Read data: " << len << endl;
			cout << "Read data: " << buff << endl;

			write(newSock, buff, len);
		}
	}
    return 0;
}