Re: newbie: socket api

From:
Ian Collins <ian-news@hotmail.com>
Newsgroups:
comp.lang.c++
Date:
Thu, 27 Dec 2012 11:28:23 +1300
Message-ID:
<ak1c07Fca55U7@mid.individual.net>
Thomas Kaufmann wrote:

** Please clean up the mess that dreadful google interface makes of your
quotes.

Here is my code:

#include "unp.h"
#include "init.h"

#include <exception>

void* InitAndConnect(int sockfd, int family, char *ip) {

   // I want return this struct
   struct sockaddr sa;


Then why don't you?

   if (family == AF_INET) {

     try {


Why have a try block here?

       struct sockaddr_in servaddr;;

       bzero(&servaddr, sizeof(servaddr) );


Just use
   sockaddr_in servaddr = {0};

rather than calling bzero.

       servaddr.sin_family = family;
       servaddr.sin_port = htons(SERV_PORT);

       if (inet_pton(family, ip, &servaddr.sin_addr) <= 0) {
    perror("inet_pton-error: ");

Should you carry on if this fails?

       }

       connect(sockfd, (SA*) &servaddr, sizeof(servaddr) );

       // critical line
       sa = servaddr;

     } catch(std::exception& e) {
       cout << e.what() << endl;
     }

   } else if (family == AF_INET6) {

     struct sockaddr_in6 servaddr;

     bzero(&servaddr, sizeof(servaddr) );
     servaddr.sin6_family = AF_INET;
     servaddr.sin6_port = htons(SERV_PORT);
     inet_pton(family, ip, &servaddr.sin6_addr);

     connect(sockfd, (SA*) &servaddr, sizeof(servaddr) );

       // critical line
       sa = servaddr;
   }

   // does' work
   return sa;


Are you surprised?

You could return something like

struct Address
{
    int family;
    union {
      sockaddr_in v4;
      sockaddr_in6 v6;
    } servaddr;
};

--
Ian Collins

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