main.c

#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>

int main(int argc, char *argv[]) {
  while (1) {
    int sockfd;
    struct addrinfo hints, *servinfo, *p;
    int rv;

    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC; // use AF_INET6 to force IPv6
    hints.ai_socktype = SOCK_STREAM;

    if ((rv = getaddrinfo("localhost", "7000", &hints, &servinfo)) != 0) {
      fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
      exit(1);
    }

    // loop through all the results and connect to the first we can
    for(p = servinfo; p != NULL; p = p->ai_next) {
      if ((sockfd = socket(p->ai_family, p->ai_socktype,
                           p->ai_protocol)) == -1) {
        perror("socket");
        continue;
      }

      if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
        if (errno == ECONNREFUSED) { continue; }
        perror("connect");
        exit(1);
      }

      break; // if we get here, we must have connected successfully
    }

    freeaddrinfo(servinfo); // all done with this structure
  }

  return 0;
}