Socket compiler errors

I'm trying to complie server.c from Beej's tutorial:
I'm using win XP and Visual C++ .net.
Code is following:

Code:

#include <winsock.h>
	#include <stdio.h>
    #define MYPORT 3490    
    #define BACKLOG 10     
    void sigchld_handler(int s)
    {
        while(wait(NULL) > 0);
    }
    int main(void)
    {
		WSADATA wsaData;
        SOCKET sockfd, new_fd;  
        struct sockaddr_in my_addr;    
        struct sockaddr_in their_addr;
        int sin_size;
        struct sigaction sa;
        int yes=1;

		if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) {
            fprintf(stderr, "WSAStartup failed.\n");
            exit(1);
        } 


        if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("socket");
            exit(1);
        }
        if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
            perror("setsockopt");
            exit(1);
        }
        
        my_addr.sin_family = AF_INET;         
        my_addr.sin_port = htons(MYPORT);     
        my_addr.sin_addr.s_addr = INADDR_ANY; 
        memset(&(my_addr.sin_zero), '\0', 8); 
        if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr))
                                                                       == -1) {
            perror("bind");
            exit(1);
        }
        if (listen(sockfd, BACKLOG) == -1) {
            perror("listen");
            exit(1);
        }
        sa.sa_handler = sigchld_handler; 
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART;
        if (sigaction(SIGCHLD, &sa, NULL) == -1) {
            perror("sigaction");
            exit(1);
        }
        while(1) {  
            sin_size = sizeof(struct sockaddr_in);
            if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr,
                                                           &sin_size)) == -1) {
                perror("accept");
                continue;
            }
            printf("server: got connection from %s\n",
                                               inet_ntoa(their_addr.sin_addr));
            if (!fork()) { 
                closesocket(sockfd); 
                if (send(new_fd, "Hello, world!\n", 14, 0) == -1)
                    perror("send");
                closesocket(new_fd);
                exit(0);
            }
            closesocket(new_fd); 
        }
        return 0;
    }

I'm getting the following errors:

c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(66): error C2065: 'fork' : undeclared identifier
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(52): error C2065: 'SA_RESTART' : undeclared identifier
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(53): error C2065: 'SIGCHLD' : undeclared identifier
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(32): error C2664: 'setsockopt' : cannot convert parameter 4 from 'int *__w64 ' to 'const char *'
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(51): error C2228: left of '.sa_mask' must have class/struct/union type
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(50): error C2228: left of '.sa_handler' must have class/struct/union type
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(52): error C2228: left of '.sa_flags' must have class/struct/union type
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(66): error C2171: '!' : illegal on operands of type ''unknown-type''
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(19): error C2079: 'sa' uses undefined struct '(void)main::sigaction'
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(10): error C2065: 'wait' : undeclared identifier
c:\Documents and Settings\Mitjko\My Documents\Visual Studio Projects\Tmp\Socketi.cpp(51): error C2065: 'sigemptyset' : undeclared identifier


I don't know how to change fork() and similar, because I don't have any experience using *nix.

What are Windows equivalents to these?
Can you help me correcting this code?

Code:

    #include <winsock.h>
    #include <stdio.h>
    #define MYPORT 3490    
    #define BACKLOG 10     

    int main(void)
    {
        WSADATA wsaData;
        SOCKET sockfd, new_fd;  
        struct sockaddr_in my_addr;    
        struct sockaddr_in their_addr;
        int sin_size;

        int yes=1;

        if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) {
            fprintf(stderr, "WSAStartup failed.\n");
            exit(1);
        } 

        if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("socket");
            exit(1);
        }
        if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,(const char*)&yes,sizeof(yes)) == -1) {
            perror("setsockopt");
            exit(1);
        }
        
        my_addr.sin_family = AF_INET;         
        my_addr.sin_port = htons(MYPORT);     
        my_addr.sin_addr.s_addr = INADDR_ANY; 
        memset(&(my_addr.sin_zero), '\0', 8); 
        if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr))
                                                                       == -1) {
            perror("bind");
            exit(1);
        }
        if (listen(sockfd, BACKLOG) == -1) {
            perror("listen");
            exit(1);
        }

        while(1) {  
            sin_size = sizeof(struct sockaddr_in);
            if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr,
                                                           &sin_size)) == -1) {
                perror("accept");
                continue;
            }
            printf("server: got connection from %s\n",
                                               inet_ntoa(their_addr.sin_addr));
            closesocket(sockfd); 
            if (send(new_fd, "Hello, world!\n", 14, 0) == -1)
                perror("send");
            closesocket(new_fd); 
        }
        return 0;
    }

There is no "equivalent" function of fork() in any Windows OS, per se. The best you can do if you want to do some multithreaded socket programming is use CreateThead(), _beginthead(), _spawnl(), etc. Otherwise just use asynchronous sockets.

[edit]
Corrected/modified the call to setsockopt()
[/edit]

I receive only one error in line

if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&yes,si zeof(int)) == -1)

error C2664: 'setsockopt' : cannot convert parameter 4 from 'int *__w64 ' to 'const char *'

hmmm... try turning int yes=1 into: char yes[]="1"

Originally Posted by Devil Panther

hmmm... try turning int yes=1 into: char yes[]="1"

No, no. Don't do that. Just cast the &yes to a const char*:

Code:

if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,(const char*)&yes,sizeof(yes)) == -1)

// notice I also changed the sizeof() parameter to "yes" instead of "int" just because I find it
// useful to have as a reminder, but either is fine.

oh well... my bad...

Thanks for help it's now working.
I do have another question.
When I execute this code and in Start\Run type:
telnet hostname 3490 I get message Hello world and after that Connection to host lost. At the same time in first window (server) I see infinte loop with text: "accept: No error", I assume it is perror("accept"). Now, when I try once more to start telnet I get message:
Could not open connection to the host, on port 3490. No connection could be made because the target machine actively refused it.
I don't think this program is supposed to do this. If someone can explain me why it is happenning and how to fix it.
Thanks

Is it possible that is happening because of thet system call fork()?
When talking about fork() that exists in *nix some people say use CreateProcess or CreateThread, but it is not equivalent because CreateThred uses couple of parameters and fork () use non!

By removing fork() from the code, the server can only deal with one connection at a time. So in other words, you don't have multi-tasking.