segmentation fault (cored dumped)

Question

I am receiving a segmentation fault (core dumped) when I execute the following code.

I am having difficulty determining why I am getting this error. I'm thinking it's a pointer issue.

Here is the code

struct info{
char *host;
char *channel;
char *user;
}Ainfo;


int main(int argc, char *argv[])
{
    struct addrinfo hints;
    struct addrinfo *result, *result2;
    int sock,getadd;

    Ainfo.host=argv[2];

    if(argc<3)
    {
       perror("too few Arguments\n");
       exit(0);
    }

    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_flags = 0;
    hints.ai_protocol = 0;


    getadd=getaddrinfo(Ainfo.host,PORT,(struct addrinfo *)&hints,&result);
    if(getadd!=0){
        perror("\n");
        exit(0);
    }

    return 0;
}

Answer 1

^{Transferring key comments into an answer.}

What is PORT defined as? POSIX says getaddrinfo() has the prototype

int getaddrinfo(const char *restrict nodename, const char *restrict servname, const struct addrinfo *restrict hints, struct addrinfo **restrict res);

and also stipulates:

The nodename and servname arguments are either null pointers or pointers to null-terminated strings. One or both of these two arguments shall be supplied by the application as a non-null pointer.

The OP notes:

• The PORT is set to 6667 — #define PORT 6667

If you have #define PORT 6667 , then that does not look like either a null pointer or a null-terminated string. So it isn't a big surprise (to me) that your code is crashing.

It is a surprise that you are not getting compiler warnings telling you that you're doing it wrong. Get the warnings enabled, or get a better compiler. And heed the warnings — the compiler knows more about C than you do. I rarely run code that doesn't compile cleanly with

gcc -O3 -g -std=c11 -Wall -Wextra -Werror -Wmissing-prototypes -Wstrict-prototypes … 

(The -Werror makes sure I deal with the warnings because the compilation fails if there are any! I sometimes add some more warnings; I rarely remove any of them.)