Hello.
Pre forgive me for my English
my program (using non blocking sockets) should connect to server, send string and async recieve replies form server.
but it cant connect to server
select return 0 (timeout)Code:#include <stdio.h> /* for printf(), fprintf() */
#include <winsock2.h> /* for socket(),... */
#include <stdlib.h> /* for exit() */
#include <time.h>
#include <sys/types.h>
#define RCVBUFSIZE 32 /* Size of receive buffer */
void DieWithError(char *errorMessage){
perror(errorMessage);
exit(0);
}; /* Error handling function */
void main(int argc, char *argv[])
{
int sock, rc; /* Socket descriptor */
struct sockaddr_in echoServAddr; /* Echo server address */
unsigned short echoServPort; /* Echo server port */
//char *servIP; /* Server IP address (dotted quad) */
char servIP[] = "10.42.43.1";
char echoString[]= "identifier=1z2y3z \r\n\r\n";
char echoBuffer[RCVBUFSIZE]; /* Buffer for echo string */
int echoStringLen; /* Length of string to echo */
int bytesRcvd, totalBytesRcvd; /* Bytes read in single recv() and total bytes read */
WSADATA wsaData; /* Structure for WinSock setup communication */
unsigned long nonblocking = 1;
fd_set writefds, readfds;
struct timeval tv;
tv.tv_sec = 5;
tv.tv_usec = 500000;
//servIP = argv[1]; /* First arg: server IP address (dotted quad) */
echoServPort = 8088; //atoi(8088); //atoi(argv[2]); /* Use given port, if any */
if (WSAStartup(MAKEWORD(2, 0), &wsaData) != 0) /* Load Winsock 2.0 DLL */
{
fprintf(stderr, "WSAStartup() failed");
exit(1);
}
/* Create a reliable, stream socket using TCP */
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) ) < 0)
DieWithError("socket() failed");
/* Set the socket to nonblocking */
if (ioctlsocket(sock, FIONBIO, &nonblocking) != 0)
DieWithError("ioctlsocket() failed");
/* Construct the server address structure */
memset(&echoServAddr, 0, sizeof(echoServAddr)); /* Zero out structure */
echoServAddr.sin_family = AF_INET; /* Internet address family */
echoServAddr.sin_addr.s_addr = inet_addr(servIP); /* Server IP address */
echoServAddr.sin_port = htons(echoServPort); /* Server port */
FD_ZERO(&writefds);
FD_SET(sock, &writefds);
rc = select(sock, NULL, &writefds, NULL, &tv);
if((rc == 1) && (FD_ISSET(sock, &writefds)))
{
/* Establish the connection to the echo server */
if (connect(sock, (struct sockaddr *) &echoServAddr, sizeof(echoServAddr)) < 0)
DieWithError("connect() failed");
}
echoStringLen = strlen(echoString); /* Determine input length */
FD_ZERO(&readfds);
FD_SET(sock, &readfds);
rc = select(sock, &readfds, NULL, NULL, &tv);
if((rc == 1) && (FD_ISSET(sock, &readfds)))
{
/* Send the string, including the null terminator, to the server */
if (send(sock, echoString, echoStringLen, 0) != echoStringLen)
DieWithError("send() sent a different number of bytes than expected");
}
/* Receive the same string back from the server */
totalBytesRcvd = 0;
printf("Received: "); /* Setup to print the echoed string */
while (totalBytesRcvd < echoStringLen)
{
/* Receive up to the buffer size (minus 1 to leave space for
a null terminator) bytes from the sender */
if ((bytesRcvd = recv(sock, echoBuffer, RCVBUFSIZE - 1, 0)) <= 0)
DieWithError("recv() failed or connection closed prematurely");
totalBytesRcvd += bytesRcvd; /* Keep tally of total bytes */
echoBuffer[bytesRcvd] = '\0'; /* Add \0 so printf knows where to stop */
printf("%s", echoBuffer); /* Print the echo buffer */
}
printf("\n"); /* Print a final linefeed */
closesocket(sock);
WSACleanup(); /* Cleanup Winsock */
exit(0);
}
