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

#define BUF_SIZE 64
#define PORT 8000
#define LISTEN_BACKLOG 32

#define handle_error(msg)                                                      \
  do {                                                                         \
    perror(msg);                                                               \
    exit(EXIT_FAILURE);                                                        \
  } while (0)

int main() {
  struct sockaddr_in addr;
  int sfd, cfd;
  ssize_t num_read;
  char buf[BUF_SIZE];

  sfd = socket(AF_INET, SOCK_STREAM, 0);
  if (sfd == -1)
    handle_error("socket");

  memset(&addr, 0, sizeof(struct sockaddr_in));
  addr.sin_family = AF_INET;
  addr.sin_port = htons(PORT);
  addr.sin_addr.s_addr = htonl(INADDR_ANY);

  if (bind(sfd, (struct sockaddr *)&addr, sizeof(struct sockaddr_in)) == -1)
    handle_error("bind");

  if (listen(sfd, LISTEN_BACKLOG) == -1)
    handle_error("listen");

  for (;;) {
    cfd = accept(sfd, NULL, NULL);
    if (cfd == -1)
      handle_error("accept");

    while ((num_read = read(cfd, buf, BUF_SIZE)) > 0) {
      if (write(STDOUT_FILENO, buf, num_read) != num_read)
        handle_error("write");

      if (num_read == -1)
        handle_error("read");
    }
  }

  if (close(cfd) == -1)
    handle_error("close");
}