创建无需任何外部执行即可连续侦听的守护程序文件

我有恶魔进程。用作服务器套接字。为了使其侦听，我在终端中手动执行它：./daemon

现在，当我想将其保留在ftp服务器上时，我无法以这种方式执行。所以我希望它继续听下去。

我在goolge上看到了如何创建它。它说具有两个fork（）的子进程和父进程将作为守护进程工作。但是我无法弄清楚应该在哪里使用哪个进程ID。这是我的代码，有人可以指导一下：

using namespace std;
void *SocketHandler(void *);

int main(int argv, char **argc)
{
    int host_port = 1103;
    char buf[20];
    int k;
    struct sockaddr_in my_addr;
    int hsock;
    int *p_int;
    int err;
    socklen_t addr_size = 0;
    int *csock;
    sockaddr_in sadr;
    pthread_t thread_id = 0;

    hsock = socket(AF_INET, SOCK_STREAM, 0);
    if (hsock == -1) {
    printf("Error initializing socket %dn", errno);
    goto FINISH;
    }

    p_int = (int *) malloc(sizeof(int));
    *p_int = 1;

    if ((setsockopt(hsock, SOL_SOCKET, SO_REUSEADDR, (char *) p_int, sizeof(int)) == -1) || (setsockopt(hsock, SOL_SOCKET, SO_KEEPALIVE, (char *) p_int, sizeof(int)) == -1)) {
    printf("Error setting options %dn", errno);
    free(p_int);
    goto FINISH;
        }
    free(p_int);

    my_addr.sin_family = AF_INET;
    my_addr.sin_port = htons(host_port);

    memset(&(my_addr.sin_zero), 0, 8);
    my_addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(hsock, (sockaddr *) & my_addr, sizeof(my_addr)) == -1) {
    fprintf(stderr, "Error binding to socket, make sure nothing else is listening on this port %dn", errno);
    goto FINISH;
    }
    if (listen(hsock, 10) == -1) {
    fprintf(stderr, "Error listening %dn", errno);
    goto FINISH;
    }
    //Now lets do the server stuff

    addr_size = sizeof(sockaddr_in);

    while (true) {
    printf("waiting for a connectionnn");
    csock = (int *) malloc(sizeof(int));
    if ((*csock = accept(hsock, (sockaddr *) & sadr, &addr_size)) != -1) {
        printf("---------------------nReceived connection from %sn", inet_ntoa(sadr.sin_addr));
        pthread_create(&thread_id, 0, &SocketHandler, (void *) csock);
        pthread_detach(thread_id);
    } else {
        fprintf(stderr, "Error accepting %dn", errno);
    }
    }

  FINISH:
    ;
}

std::pair < int, std::string > mytransform(const std::pair < std::string, int >p)
{
    return std::pair < int, std::string > (p.second, p.first);
}

void *SocketHandler(void *lp)
{
    int ar[10];
    int result=0;
    int *csock = (int *) lp;
    char buf[20];
    int k;
    char *skp;
    char *str;
    char *str2;

        std::stringstream ss;
    std::multimap < int, std::string, std::greater < int >>dst;
        std::multimap < int, std::string >::iterator rec;
        std::map < std::string, int >src;
        std::map < int, std::vector < std::string > >three_highest; 
        std::vector < std::string > writable;
    std::string item;
    std::ostringstream bfr; 
    std::string result_string;
    std::istringstream iss;
    std::ostringstream oss;
  //    std::multimap < int, std::string >::iterator it; 


    std::vector<std::string> most;
    int max_count = 0;
    int tmp=0;

    int pcount = 0, ncount = 0;

    char buffer[1024];
    int buffer_len = 1024;
    int bytecount;

    int i = 0,t=0,q=0;
    int j = 0;
    char *ch[50] = { 0 };   /* stores references to 50 words. */
    char *ch2[50] = { 0 };  
    char *excluded_string[50] = { 0 };

        char *word = strtok(buffer, " ");
        char *word2 = strtok(buffer, " ");

        char *portstring1=(char *)malloc(sizeof(buffer));
        char *portstring2=(char *)malloc(sizeof(buffer));

    memset(buffer, 0, buffer_len);
    if ((bytecount = recv(*csock, buffer, buffer_len, 0)) == -1) {
    fprintf(stderr, "Error receiving data %d n", errno);
    goto FINISH;
    }
    printf("Received bytes %d nReceived string  %s n ", bytecount, buffer);
    word = strtok(buffer, " ");

    while ((NULL != word) && (50 > i)) {
    ch[i] = strdup(word);
    excluded_string[j]=strdup(word);
    word = strtok(NULL, " ");
    skp = BoyerMoore_skip(ch[i], strlen(ch[i]) );
    if(skp != NULL)
    {
        i++;
        continue;
     }
    printf("exclueded : %s  and %s size %d n",excluded_string[j],ch[i],sizeof(excluded_string));
    bfr << excluded_string[j] << " ";
    result_string = bfr.str();
    j++;    
    //  std::cout << "string is :" << r1;

    }
        std::cout << "string is :" << result_string << "n";

            ss<<result_string;

        while (std::getline(ss, item, ' ')) {
            writable.push_back(item);
        }

        for (std::vector < std::string >::iterator it = writable.begin(); it != writable.end(); it++)
            ++src[*it];

        std::transform(src.begin(), src.end(), std::inserter(dst, dst.begin()), mytransform);

    rec=dst.begin();   
    for (auto it = dst.begin(); it != dst.end(); ++it)
        std::cout << it->second << ":" << it->first << std::endl;

    while (three_highest.size() < 3 && rec != dst.end()) {
        three_highest[rec->first].push_back(rec->second);
        rec++;
       }

    //std::cout << "nthree_highest:n";
    i=0;
    for (std::map < int, std::vector < std::string > >::iterator hit = three_highest.begin(); hit != three_highest.end(); ++hit) {
    //std::cout << hit->first << ":";

    for (std::vector < std::string >::iterator vit = (*hit).second.begin(); vit != (*hit).second.end(); vit++) {
        std::cout << hit->first << ":";
        std::cout << *vit << "n";
        ar[i]= hit-> first;
        printf(" ar : %d n",ar[i]);
        i++;
        oss << hit->first << " " << *vit << "n";
    }
    }
    printf( "i is  :%d n",i);

    if ((bytecount = send(*csock, (char *)ar, i *sizeof(int), 0)) == -1) { // Here we cant send lenth-1. It consider exact
    fprintf(stderr, "Error sending data %dn", errno);
    goto FINISH;
    }

  FINISH:
    free(csock);
    return 0;
}