Re: [Dev-C++] Q: Portable of DEV-CPP under WIN2K?

[Daniel K. O. <dan...@ya...>]

Yin Ming wrote:

>Since not wiliing to learn WIN API totally, I want to port it via
>DEV-CPP,  I mean the mingw32 libs it includes, with a little modification,  
>But those libs seems not complete, I cannot find sys/socket in dev-cpp/includes.
>And none of my fellows wants to install huge of files, such as Cynwin...
>Can dev-cpp do this porting? Or I must rewrite in python or java?
>  
>
It probably can.
For sockets you have to use winsock. But remember that there are many 
incompatibilities. Some things to keep in mind:

    * Windows sockets are *not* file descriptors. That means no read(),
      no write(), and most important: *no close()*. You close sockets
      with closesocket().
    * Winsock needs to be initialized with WSAStartup and finalized with
      WSACleanup.
    * Windows sockets are *unsigned*, not signed. Expressions like
      "sock<0" that are commong for detecting invalid file descriptors
      won't work. An invalid socket has the value INVALID_SOCKET.
    * The error codes (like EINVAL, ENETDOWN, etc) are present, but with
      the "WSA" prefix (WSAEINVAL, WSAENETDOWN...).
    * Instead of using fcntl for non-blocking sockets, use ioctlsocket.
    * select() will accuse a non-blocking socket as readable/writable
      most of the time, when it isn't. In this case, *every* send/recv
      call should check for WSAEWOULDBLOCK.
    * Because of this, you can't get high-speed transfers with
      non-blocking sockets... you hit the wall at 2~5 MB/s.
    * You check error codes with WSAGetLastError, not with errno. There
      are no strings for winsock errors (i.e. strerror).
    * inet_addr() will crash your program if you send it non-ASCII
      chars, specially if you run it in a locale other than "C".


For network programs I usually have a header that looks like this:
---
#ifdef WIN32
#include <winsock2.h>
        #define NET_STARTUP     {       WSADATA wsa; \
                                        WSAStartup(MAKEWORD(2, 0), &wsa); \
                                        atexit((void (*)())WSACleanup); }
#else
// *nix?
        #define NET_STARTUP
        #include <sys/socket.h>
        #include <netdb.h>
        #include <netinet/in.h>
        #include <arpa/inet.h>
        #include <netdb.h>
        #include <unistd.h>

        #define SOCKET int
        #ifndef SOCKET_ERROR
                #define SOCKET_ERROR -1
        #endif
        #define INVALID_SOCKET   -1
        typedef struct sockaddr_in SOCKADDR_IN;
        typedef struct sockaddr SOCKADDR;
        #define closesocket(x)  close(x)
#endif
---

I hope it helps. For mor info, look for the winsock documentation at 
msdn.com.



Daniel K. O.