title: warning: "IPPROTO_TCP" redefined warning: this is the location of the previous definition
body: <p>I am getting this warning when compiling </p>
  
  <p>In file included from server.c:48:</p>
  
  <blockquote>
    <p>unixwin.h:23:1: warning: "IPPROTO_TCP"
    redefined In file included from
    server.c:42:
    /usr/include/netinet/in.h:45:1:
    warning: this is the location of the
    previous definition</p>
  </blockquote>
  
  <p>below is the sections refered to in the error:</p>
  
  <pre><code>file unixwin.h
  15
   16 #ifndef FALSE
   17 #define FALSE 0
   18 #endif
   19
   20 #define SOCKADDR_IN struct sockaddr_in
   21 #define SOCKET_ERROR -1
   22 #define INVALID_SOCKET (SOCKET)(~0)
   23 #define IPPROTO_TCP 6
   24 #define LPSOCKADDR struct sockaddr *
   25 #define GMEM_MOVEABLE 1
   26 #define GMEM_FIXED 2
   27 #define GMEM_SHARE 3
   28 #define GPTR 4
   29 #define LPHOSTENT struct hostent *
   30 #define LPIN_ADDR struct in_addr *
   31
   32 #ifndef UINT
   33 #define UINT unsigned int
   34 #endif
   35
  </code></pre>
  
  <p>In file server.c</p>
  
  <pre><code>37
    38 #ifdef UNIX
    39 #include &lt;sys/types.h&gt;
    40 #include &lt;sys/socket.h&gt;
    41 #include &lt;sys/ioctl.h&gt;
    42 #include &lt;netinet/in.h&gt;
    43 #include &lt;arpa/inet.h&gt;
    44 #include &lt;time.h&gt;
    45 #ifndef FIONREAD
    46 #include &lt;sys/filio.h&gt;
    47 #endif
    48 #include "unixwin.h"
    49 #endif
    50
  </code></pre>
  
  <p>And in file /usr/include/netinet/in.h</p>
  
  <pre><code>30
   31 /* Standard well-defined IP protocols.  */
   32 enum
   33   {
   34     IPPROTO_IP = 0,        /* Dummy protocol for TCP.  */
   35 #define IPPROTO_IP              IPPROTO_IP
   36     IPPROTO_HOPOPTS = 0,   /* IPv6 Hop-by-Hop options.  */
   37 #define IPPROTO_HOPOPTS         IPPROTO_HOPOPTS
   38     IPPROTO_ICMP = 1,      /* Internet Control Message Protocol.  */
   39 #define IPPROTO_ICMP            IPPROTO_ICMP
   40     IPPROTO_IGMP = 2,      /* Internet Group Management Protocol. */
   41 #define IPPROTO_IGMP            IPPROTO_IGMP
   42     IPPROTO_IPIP = 4,      /* IPIP tunnels (older KA9Q tunnels use 94).  */
   43 #define IPPROTO_IPIP            IPPROTO_IPIP
   44     IPPROTO_TCP = 6,       /* Transmission Control Protocol.  */
   45 #define IPPROTO_TCP             IPPROTO_TCP
   46     IPPROTO_EGP = 8,       /* Exterior Gateway Protocol.  */
   47 #define IPPROTO_EGP             IPPROTO_EGP
   48     IPPROTO_PUP = 12,      /* PUP protocol.  */
   49 #define IPPROTO_PUP             IPPROTO_PUP
   50     IPPROTO_UDP = 17,      /* User Datagram Protocol.  */
   51 #define IPPROTO_UDP             IPPROTO_UDP
   52     IPPROTO_IDP = 22,      /* XNS IDP protocol.  */
   53 #define IPPROTO_IDP             IPPROTO_IDP
   54     IPPROTO_TP = 29,       /* SO Transport Protocol Class 4.  */
   55 #define IPPROTO_TP              IPPROTO_TP
   56     IPPROTO_IPV6 = 41,     /* IPv6 header.  */
   57 #define IPPROTO_IPV6            IPPROTO_IPV6
   58     IPPROTO_ROUTING = 43,  /* IPv6 routing header.  */
   59 #define IPPROTO_ROUTING         IPPROTO_ROUTING
   60     IPPROTO_FRAGMENT = 44, /* IPv6 fragmentation header.  */
  </code></pre>
  
  <p>Can you say where the text is wrong
  thanks</p>