Problem while compiling socket connect code in C

Question

struct hostent *lh               = gethostbyname(hostname);

int socketDescriptor             = socket(AF_INET,SOCK_STREAM, 0);

sockaddr_in socketInfo;

memset(&socketInfo, 0, sizeof(socketInfo));
socketInfo.sin_family            = AF_INET;
socketInfo.sin_addr.s_addr       = ((in_addr *)(lh->h_addr))->s_addr;
socketInfo.sin_port              = htons(portNumber);

connect(socketDescriptor,&socketInfo,sizeof(socketInfo));

When trying to compile, I get the following error:

error: cannot convert ‘sockaddr_in*’ to ‘const sockaddr*’ for argument ‘2’ to ‘int connect(int, const sockaddr*, socklen_t)’

Things look "by the book", but I am missing something (obviously). What is it?

Answer 1

I think you are missing struct on sockaddr_in socketInfo. So it should be struct sockaddr_in socketInfo.

Also casting socketInfo to struct sockaddr * would be nice.

connect(socketDescriptor,&socketInfo,sizeof(socketInfo));

Should be

connect(socketDescriptor,(struct sockaddr *) &socketInfo,sizeof(socketInfo));

Answer 2

  struct addrinfo *server;
  struct addrinfo hints; 

    memset(&hints, 0, sizeof(struct addrinfo));/*set hints*/
    hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
    hints.ai_socktype = SOCK_STREAM; 
    hints.ai_flags = 0;
    hints.ai_protocol = 0;          /* Any protocol */

 getaddrinfo(srvname,port,&hints,&server); /*get server ip fit args*/

 sid = socket(server->ai_family, server->ai_socktype,server->ai_protocol)
 connect(sid,server->ai_addr, server->ai_addrlen)

Those are some codesnipets that will work and that you can start from.

What happens here is that I set up one struct with all the intel and than combine it with some more info to get one nice all pointers fit structure too pass to connect. hope that helps