// This is the client socket for TCP connecting // Sends and receives string data from/to TCP server #include #include #include #include #include #include #include #include short socketCreate (void); void errorDisplay (char *msg); int socketConnect (short hSocket, char*server_addr); int socketSend (short hSocket, char *Rqst, int lenRqst); int socketReceive (short hSocket, char *Rsp, int RvcSize); short global_sock = 0; void sigintHandler (int signum); void (*sigintPTR)(int); int main() { short hSocket =0; char sendToServer [100]={'\0'}; char server_reply [200]={'\0'}; char server_addr[16]={'\0'}; int x =1; //This part for handling the CTRL+C signal and safely closing connection sigintPTR = sigintHandler; struct sigaction act, oldact; act.sa_handler = sigintPTR; oldact.sa_handler = sigintPTR; printf ("\nInsert Server IP: "); fgets (server_addr,16,stdin); printf ("\nFor exit press CTRL+C: "); while (x){ hSocket = socketCreate (); socketConnect (hSocket,server_addr); printf ("\nEnter the Message: "); fgets (sendToServer,100, stdin); socketSend (hSocket, sendToServer, strlen (sendToServer)); socketReceive (hSocket, server_reply, 200); printf ("\nServer response: %s", server_reply); sigaction (SIGINT, &act, &oldact);//Handling CTRL+C global_sock = hSocket;//This I'm using for safely closing connection in handler function close (hSocket); } return 0; } //Create socket short socketCreate (void) { short hSocket = 0; hSocket = socket(AF_INET,SOCK_STREAM,0); if (hSocket<0){ char *msg = "ERROR Can't create socket"; errorDisplay (msg); exit (-1); } return hSocket; } //For errors dispaying void errorDisplay (char *msg) { perror (msg); } //Connect int socketConnect (short hSocket, char*server_addr) { int result =0; int serverPort = 12345; struct sockaddr_in server={0}; server.sin_addr.s_addr = inet_addr (server_addr); server.sin_family=AF_INET; server.sin_port = htons (serverPort); result = connect (hSocket, (struct sockaddr*)&server, sizeof(server)); if (result!=0){ char *msg = "Can't connect to the server"; errorDisplay (msg); return -1; } return 0; } //Send data int socketSend (short hSocket, char *Rqst, int lenRqst) { int result=0; struct timeval tv= {0} ; tv.tv_sec = 20; if(setsockopt (hSocket, SOL_SOCKET,SO_SNDTIMEO, (char*)&tv,sizeof(tv) ) <0){ char *msg ="\nTime out"; errorDisplay (msg); return -1; } result = send (hSocket, Rqst, lenRqst,0); if (result <0){ char *msg ="\nCan't send data to the server"; errorDisplay(msg); return -1; } if (result != lenRqst) printf ("\nSome data lost"); return result; } //Receive data from server int socketReceive (short hSocket, char *Rsp, int RvcSize) { int result=0; struct timeval tv= {0} ; tv.tv_sec = 20; if(setsockopt (hSocket, SOL_SOCKET,SO_RCVTIMEO, (char*)&tv,sizeof(tv) ) <0){ char *msg ="\nTime out"; errorDisplay (msg); return -1; } result = recv (hSocket, Rsp, RvcSize,0); if (result <0){ char *msg ="\nCan't receive data from the server"; errorDisplay(msg); return -1; } return result; } //Handler for CTRL+C void sigintHandler (int signum) { if (close (global_sock)==0){ puts ("\n\n Socket closed successful!"); puts ("\n Goodbye!!!!"); exit (-2);} else { errorDisplay ("\nCan't close socket"); exit (-3); } }

ClientTCP