title: C++ socket error C1083: Cannot open include file: 'unistd.h': No such file or directory
body: <p>I'm following this tutorial <strong><a href="https://www.geeksforgeeks.org/socket-programming-cc/" rel="nofollow noreferrer">https://www.geeksforgeeks.org/socket-programming-cc/</a></strong>. I'm trying to practice Socket Programming in C/C++. Can someone tell me why I'm recieving this error and how to fix it? </p>
  
  <p><strong>error C1083: Cannot open include file: 'unistd.h': No such file or directory</strong></p>
  
  <p>thanks in advance</p>
  
  <pre><code>#include&lt;iostream&gt;
  #include&lt;string&gt;
  #include &lt;unistd.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;sys/socket.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;netinet/in.h&gt;
  #include &lt;string.h&gt;
  #define PORT 8080
  
  using namespace std;
  
  int main()
  {
  
      int server_fd, new_socket, valread;
      struct sockaddr_in address;
      int opt = 1;
      int addrlen = sizeof(address);
      char buffer[1024] = { 0 };
      char *hello = "Hello from server";
  
      // Creating socket file descriptor
      if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0)
      {
          perror("socket failed");
          exit(EXIT_FAILURE);
      }
  
      // Forcefully attaching socket to the port 8080
      if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT,
          &amp;opt, sizeof(opt)))
      {
          perror("setsockopt");
          exit(EXIT_FAILURE);
      }
      address.sin_family = AF_INET;
      address.sin_addr.s_addr = INADDR_ANY;
      address.sin_port = htons(PORT);
  
      // Forcefully attaching socket to the port 8080
      if (bind(server_fd, (struct sockaddr *)&amp;address,
          sizeof(address))&lt;0)
      {
          perror("bind failed");
          exit(EXIT_FAILURE);
      }
      if (listen(server_fd, 3) &lt; 0)
      {
          perror("listen");
          exit(EXIT_FAILURE);
      }
      if ((new_socket = accept(server_fd, (struct sockaddr *)&amp;address,
          (socklen_t*)&amp;addrlen))&lt;0)
      {
          perror("accept");
          exit(EXIT_FAILURE);
      }
      valread = read(new_socket, buffer, 1024);
      printf("%s\n", buffer);
      send(new_socket, hello, strlen(hello), 0);
      printf("Hello message sent\n");
      return 0;
  
  
  return 0;
  }
  </code></pre>