socket message.

[legendarysnake]

My problem is in line 162
i need check if my buffer is = 'add' to do something.
but it does not work as the message is not = 'add'

#include <stdio.h>
#include <iostream>
#include <string.h> //strlen
#include <stdlib.h>
#include <errno.h>
#include <unistd.h> //close
#include <arpa/inet.h> //close
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h> //FD_SET, FD_ISSET, FD_ZERO macros
#include "mysqlite.h"
#include <sqlite3.h> 
#include <vector>
#include <string>
#include <sstream>

#define TRUE 1
#define FALSE 0
#define PORT 8888

struct ClientState
{
    ClientState() :
        sock(-1),
        loggedin(false)
    {
    }

    ClientState(int s) :
        sock(s),
        loggedin(false)
    {
    }

    int sock;
    bool loggedin;
    std::string user;
    std::string password;
    std::string command;
};
static int callback(void *data, int argc, char **argv, char **azColName){
   int i;
   fprintf(stderr, "%s: ", (const char*)data);
   for(i=0; i<argc; i++){
      printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
   }
   printf("\n");
   return 0;
}
int main(int argc , char *argv[])
{
    struct sockaddr_in address;
    std::vector<ClientState> client_socket;
sqlite3 * db;
    char * sql;
    sqlite3_stmt * stmt;
    int nrecs;
    char * errmsg;
    int i;
    int row = 0;
   const char* data = "Callback function called";
    //create a master socket
    int master_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (master_socket < 0)
    {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
//open database
int rc = sqlite3_open("rpg.db", &db);
   if( rc ){
      fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
      exit(0);
   }else{
      fprintf(stderr, "Opened database successfully\n");
   }

    //set master socket to allow multiple connections , this is just a good habit, it will work without this
    int opt = TRUE;
    if (setsockopt(master_socket, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, sizeof(opt)) < 0)
    {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }

    //type of socket created
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    //bind the socket to localhost port 8888
    if (bind(master_socket, (struct sockaddr *)&address, sizeof(address)) < 0)
    {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }
    printf("Listener on port %d \n", PORT);

    //try to specify maximum of 3 pending connections for the master socket
    if (listen(master_socket, 5) < 0)
    {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    puts("Waiting for connections ...");

    while (TRUE)
    {
        //set of socket descriptors
        fd_set readfds;
        FD_ZERO(&readfds);                  //clear the socket set
        FD_SET(master_socket, &readfds);    //add master socket to set
        int max_sd = master_socket;

        //add child sockets to set
        for (size_t i = 0; i < client_socket.size(); ++i)
        {
            FD_SET(client_socket[i].sock, &readfds);
            max_sd = std::max(max_sd, client_socket[i].sock);
        }

        //wait for an activity on one of the sockets , timeout is NULL , so wait indefinitely
        int activity = select( max_sd + 1 , &readfds , NULL , NULL , NULL);
        if ((activity < 0) && (errno != EINTR))
        {
            printf("select error");
        }

        //else its some IO operation on some other socket :)
        for (std::vector<ClientState>::iterator p = client_socket.begin(); p != client_socket.end(); )
        {
            char buffer[1024]; //data buffer of 1K

            if (FD_ISSET(p->sock, &readfds))
            {
                //Check if it was for closing , and also read the incoming message
                int valread = recv(p->sock, buffer, sizeof(buffer), 0);
                if (valread <= 0)
                {
                    //Somebody disconnected , get his details and print
                    socklen_t addrlen = sizeof(address);
                    getpeername(p->sock, (struct sockaddr*)&address, (socklen_t*)&addrlen);

                    printf("Host disconnected , ip %s , port %d \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));

                    //Close the socket and mark as 0 in list for reuse
                    close(p->sock);
                    p = client_socket.erase(p);
                }
                //Echo back the message that came in
                else


                {
const char *msg ="xxxxxxxxxxxxxxx:";

int a = recv(p->sock, buffer, sizeof(buffer), 0);
if (a> 2){

if (buffer == "add"){



			send(p->sock , msg , strlen(msg), 0);
}

};





                    // is user logged in?
                    if (!p->loggedin)
                    {
                        const char *message ="username:";
                        send(p->sock , message , strlen(message), 0);
                        int n = recv(p->sock, buffer, sizeof(buffer), 0);
if (n > 2)  // account for trailing \r\n{
                        {
			p->user.assign(buffer, n - 2);
			message = "password required" ;
			send(p->sock , message , strlen(message), 0);
			n = recv(p->sock, buffer, sizeof(buffer), 0);
                        if (n > 2)  // account for trailing \r\n
                        {
                            p->loggedin = true;
			    p->password.assign(buffer, n - 2);


                   





  
//sql = "SELECT * from users";
//CALL_SQLITE (prepare_v2 (db, sql, strlen (sql) + 1, & stmt, NULL));
 //while (1) {
//        int s;
//double f = 23.43;
 //std::string f_str = std::to_string(f);
// s = sqlite3_step (stmt);
 //   std::string  sa;


//std::cout << f_str << '\n';
//}                           
 std::ostringstream os;
                            
                            std::string str = os.str();
                            send(p->sock, &str[0], str.size(), 0);
                        }}
                    }

                    ++p;
                }
            }
            else
            {
                ++p;
            }
        }

        //If something happened on the master socket , then its an incoming connection
        if (FD_ISSET(master_socket, &readfds))
        {
            //accept the incoming connection
            socklen_t addrlen = sizeof(address);
            int new_socket = accept(master_socket, (struct sockaddr *)&address, (socklen_t*)&addrlen);
            if (new_socket < 0)
            {
                perror("accept");
                exit(EXIT_FAILURE);
            }

            //inform user of socket number - used in send and receive commands
            printf("New connection , socket fd is %d , ip is : %s , port : %d \n", new_socket, inet_ntoa(address.sin_addr), ntohs(address.sin_port));

            //send new connection greeting message
            const char *message = "Welcome to the server\r\n";
            if (send(new_socket, message, strlen(message), 0) != strlen(message))
            {
                perror("send");
            }

            puts("Welcome message sent successfully");

            //add new socket to array of sockets
            client_socket.push_back(new_socket);
        }
    }

    return 0;
}

[Chervil]

char buffer[1024];
You can't compare the contents of the buffer like this:

    if (buffer == "add")

(that code will actually compare the addresses of the two character arrays.

Instead use strcmp()

    if ( !strcmp(buffer, "add") )

Note the ! (not) because the function returns zero if the strings are the same.

http://www.cplusplus.com/reference/cstring/strcmp/

[legendarysnake]

i tried

const char *msg ="xxxxxxxxxxxxxxx:";

int a = recv(p->sock, buffer, sizeof(buffer), 0);
if (a> 0){

  if( !strcmp(buffer, "add") ==0)
{



			send(p->sock , msg , strlen(msg), 0);
}

};

it send the msg even if the buffer = ""

[Peter87]

You are testing the return value of strcmp the wrong way. It should be

if(strcmp(buffer, "add") == 0)

or

if(!strcmp(buffer, "add"))

[legendarysnake]

my problem is with my buffer

i used it

 char buffer[1024]; //data buffer of 1K

            if (FD_ISSET(p->sock, &readfds))
            {
                //Check if it was for closing , and also read the incoming message
                int valread = recv(p->sock, buffer, sizeof(buffer), 0);

but the message i receive in the buffer is not the same i send, it have newline
and most of time the buffer hold a previous message.

[legendarysnake]

try run this code
my problem is with the line 158 - 163.
the condition is not == 0 even if a send the add message using netcat.

#include <stdio.h>
#include <iostream>
#include <string.h> //strlen
#include <stdlib.h>
#include <errno.h>
#include <unistd.h> //close
#include <arpa/inet.h> //close
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h> //FD_SET, FD_ISSET, FD_ZERO macros
#include "mysqlite.h"
#include <sqlite3.h> 
#include <vector>
#include <string>
#include <sstream>

#define TRUE 1
#define FALSE 0
#define PORT 8000

struct ClientState
{
    ClientState() :
        sock(-1),
        loggedin(false)
    {
    }

    ClientState(int s) :
        sock(s),
        loggedin(false)
    {
    }

    int sock;
    bool loggedin;
    std::string user;
    std::string password;
    std::string command;
};
static int callback(void *data, int argc, char **argv, char **azColName){
   int i;
   fprintf(stderr, "%s: ", (const char*)data);
   for(i=0; i<argc; i++){
      printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
   }
   printf("\n");
   return 0;
}
int main(int argc , char *argv[])
{
    struct sockaddr_in address;
    std::vector<ClientState> client_socket;
sqlite3 * db;
    char * sql;
    sqlite3_stmt * stmt;
    int nrecs;
    char * errmsg;
    int i;
    int row = 0;
   const char* data = "Callback function called";
    //create a master socket
    int master_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (master_socket < 0)
    {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
//open database
int rc = sqlite3_open("rpg.db", &db);
   if( rc ){
      fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
      exit(0);
   }else{
      fprintf(stderr, "Opened database successfully\n");
   }

    //set master socket to allow multiple connections , this is just a good habit, it will work without this
    int opt = TRUE;
    if (setsockopt(master_socket, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, sizeof(opt)) < 0)
    {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }

    //type of socket created
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    //bind the socket to localhost port 8888
    if (bind(master_socket, (struct sockaddr *)&address, sizeof(address)) < 0)
    {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }
    printf("Listener on port %d \n", PORT);

    //try to specify maximum of 3 pending connections for the master socket
    if (listen(master_socket, 5) < 0)
    {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    puts("Waiting for connections ...");

    while (TRUE)
    {
        //set of socket descriptors
        fd_set readfds;
        FD_ZERO(&readfds);                  //clear the socket set
        FD_SET(master_socket, &readfds);    //add master socket to set
        int max_sd = master_socket;

        //add child sockets to set
        for (size_t i = 0; i < client_socket.size(); ++i)
        {
            FD_SET(client_socket[i].sock, &readfds);
            max_sd = std::max(max_sd, client_socket[i].sock);
        }

        //wait for an activity on one of the sockets , timeout is NULL , so wait indefinitely
        int activity = select( max_sd + 1 , &readfds , NULL , NULL , NULL);
        if ((activity < 0) && (errno != EINTR))
        {
            printf("select error");
        }

        //else its some IO operation on some other socket :)
        for (std::vector<ClientState>::iterator p = client_socket.begin(); p != client_socket.end(); )
        {
            char buffer[1024]; //data buffer of 1K

            if (FD_ISSET(p->sock, &readfds))
            {
                //Check if it was for closing , and also read the incoming message
                int valread = recv(p->sock, buffer, sizeof(buffer), 0);
                if (valread <= 0)

                {
                    //Somebody disconnected , get his details and print
                    socklen_t addrlen = sizeof(address);
                    getpeername(p->sock, (struct sockaddr*)&address, (socklen_t*)&addrlen);

                    printf("Host disconnected , ip %s , port %d \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));

                    //Close the socket and mark as 0 in list for reuse
                    close(p->sock);
                    p = client_socket.erase(p);
                }
                //Echo back the message that came in
                else


                {
 if( strcmp(buffer, "add") ==0)
{
puts(buffer);
};




                    // is user logged in?
                    if (!p->loggedin)
                    {
                        const char *message ="username:";
                        send(p->sock , message , strlen(message), 0);
                        int n = recv(p->sock, buffer, sizeof(buffer), 0);
if (n > 2)  // account for trailing \r\n{
                        {
			p->user.assign(buffer, n - 2);
			message = "password required" ;
			send(p->sock , message , strlen(message), 0);
			n = recv(p->sock, buffer, sizeof(buffer), 0);
                        if (n > 2)  // account for trailing \r\n
                        {
                            p->loggedin = true;
			    p->password.assign(buffer, n - 2);


                   





  
//sql = "SELECT * from users";
//CALL_SQLITE (prepare_v2 (db, sql, strlen (sql) + 1, & stmt, NULL));
 //while (1) {
//        int s;
//double f = 23.43;
 //std::string f_str = std::to_string(f);
// s = sqlite3_step (stmt);
 //   std::string  sa;


//std::cout << f_str << '\n';
//}                           
 std::ostringstream os;
                            
                            std::string str = os.str();
                            send(p->sock, &str[0], str.size(), 0);
                        }}
                    }

                    ++p;
                }
            }
            else
            {
                ++p;
            }
        }

        //If something happened on the master socket , then its an incoming connection
        if (FD_ISSET(master_socket, &readfds))
        {
            //accept the incoming connection
            socklen_t addrlen = sizeof(address);
            int new_socket = accept(master_socket, (struct sockaddr *)&address, (socklen_t*)&addrlen);
            if (new_socket < 0)
            {
                perror("accept");
                exit(EXIT_FAILURE);
            }

            //inform user of socket number - used in send and receive commands
            printf("New connection , socket fd is %d , ip is : %s , port : %d \n", new_socket, inet_ntoa(address.sin_addr), ntohs(address.sin_port));

            //send new connection greeting message
            const char *message = "Welcome to the server\r\n";
            if (send(new_socket, message, strlen(message), 0) != strlen(message))
            {
                perror("send");
            }

            puts("Welcome message sent successfully");

            //add new socket to array of sockets
            client_socket.push_back(new_socket);
        }
    }

    return 0;
}

[kbw]

Break you program into functions.

Use proper indentation.

Pun the server in a debugger.