My attempt at making an erlang node

erl_node.c

//To make gethostname be defined
#define _BSD_SOURCE

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

#include "erl-commands.h"

#define BUFSIZE 1000

int my_listen(int port);
void handle_msg(ErlMessage emsg);

extern int fd; //erlang connection
extern char * rem_name;

int main(int argc, char **argv) {

  if (argc <= 4 || !strcmp(argv[1],"-h") || !strcmp(argv[1],"--help")) {
    printf("\nUsage: ./redis-proxy <sname> <lport> <rem-sname> <cookie> <redis-host> <redis-port>\n\n");
    printf("    sname           the short name you want this c-node to connect as\n");
    printf("    lport           the port you want this node to listen for new erlang connections on\n");
    printf("    rem-name        the long name of the node you want to connect to\n");
    printf("    cookie          the authentication cookie\n");
    return 0;
  }

  char * sname = argv[1];
  int port = atoi(argv[2]);
  rem_name = argv[3];
  char * cookie = argv[4];

  char hostname[50];
  gethostname(hostname,50);

  char full_name[50];
  full_name[0] = '\0';
  strncat(full_name,sname,50);
  strncat(full_name,"@",50);
  strncat(full_name,"127.0.0.1",50);

  struct in_addr addr;                     /* 32-bit IP number of host */
  int listen;                              /* Listen socket */
  int fd;                                  /* fd to Erlang node */
  ErlConnect conn;                         /* Connection data */

  erl_init(NULL, 0);

  addr.s_addr = inet_addr("127.0.0.1");

  fprintf(stderr, "running erl_connect_xinit\n");
  if (erl_connect_xinit(hostname, sname, full_name, &addr, cookie, 0) == -1)
    erl_err_quit("erl_connect_xinit");

  /* Make a listen socket */
  fprintf(stderr, "setting up listen\n");
  if ((listen = my_listen(port)) <= 0)
    erl_err_quit("my_listen");

  fprintf(stderr, "publishing port\n");
  if (erl_publish(port) == -1)
    erl_err_quit("erl_publish");

  fprintf(stderr, "accepting\n");
  if ((fd = erl_accept(listen, &conn)) == ERL_ERROR)
    erl_err_quit("erl_accept");

  fprintf(stderr, "Connected to %s\n\r", conn.nodename);

  int loop = 1;
  while (loop) {

    unsigned char buf[BUFSIZE];
    ErlMessage emsg;
    int got = erl_receive_msg(fd, buf, BUFSIZE, &emsg);

    if (got == ERL_TICK) {
      /* ignore */
    }

    else if (got == ERL_ERROR) {
      loop = 0;
    }

    else if (emsg.type == ERL_REG_SEND) {

        handle_msg(emsg);
        erl_free_term(emsg.from);
        erl_free_term(emsg.msg);
        erl_free_term(emsg.to);

    }
  }

  return 0;
}

int my_listen(int port) {
  int listen_fd;
  struct sockaddr_in addr;
  int on = 1;

  if ((listen_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    return (-1);

  setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));

  memset((void*) &addr, 0, (size_t) sizeof(addr));
  addr.sin_family = AF_INET;
  addr.sin_port = htons(port);
  addr.sin_addr.s_addr = htonl(INADDR_ANY);

  if (bind(listen_fd, (struct sockaddr*) &addr, sizeof(addr)) < 0)
    return (-1);

  listen(listen_fd, 5);
  return listen_fd;
}

void handle_msg(ErlMessage emsg) {

    if (!ERL_IS_TUPLE(emsg.msg)) return;

    ETERM * _command = erl_element(1,emsg.msg);
    erl_send(fd, emsg.from, _command);
    erl_free_term(_command);

}