All geek questions in one place

Creating daemon processing from a server socket

I have one socket that acts as a server at runtime and responds to some results. First I compile it: g++ -oa daemon.cpp dictionary.cpp -lpthread c++11 then do: ./a

Now he will listen to the request on some port.

I want me to create an object file a , it should not be executed manually. Rather, we work as a daemon file that constantly listens for a request.

I saw using fork() id, something can be done. But I could not fix the place in my lower code:

changing the variable:

 using namespace std; using namespace boost; void *SocketHandler(void *); int main(int argv, char **argc) { 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); int pid; pid_t pid=fork(); if(pid<0) exit(EXIT_FAILURE); else if(pid>0){ //this is parent process, exit now exit(EXIT_SUCCESS); // again no goto } else{ //this is child or daemon unmask(); pid_t childid = setsid(); while (true) { printf("waiting for a connectionn\n"); csock = (int *) malloc(sizeof(int)); if ((*csock = accept(hsock, (sockaddr *) & sadr, &addr_size)) != -1) { printf("---------------------nReceived connection from %s\n", inet_ntoa(sadr.sin_addr)); pthread_create(&thread_id, 0, &SocketHandler, (void *) csock); pthread_detach(thread_id); } else { fprintf(stderr, "Error accepting %dn", errno); } sleep(60); } FINISH: ; } void *SocketHandler(void *lp) { char *ch;/* stores references to 50 words. */ char *ch2[50] = { 0 }; char *excluded_string; char *word; if ((bytecount = recv(*csock, (char*) rcv.c_str(), rcv.length(), 0)) == -1) { fprintf(stderr, "Error receiving data %d \n", errno); goto FINISH; } do { bytesReceived = recv(*csock, buffer.data(), buffer.size(), 0); // append string from buffer. if ( bytesReceived == -1 ) { fprintf(stderr, "Error receiving data %d \n", errno); goto FINISH; } else rcv.append( buffer.cbegin(), buffer.cend() ); } while ( bytesReceived == MAX_BUF_LENGTH ); word = strtok(& rcv[0]," "); while (word!= NULL) { skp = BoyerMoore_skip(word, strlen(word) ); if(skp != NULL) { i++; printf("this also \n"); word = strtok(NULL, " "); continue; } printf("\n Word %s \n",word); bfr << word << " "; result_string = bfr.str(); word = strtok(NULL, " "); j++; } 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; 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 %d\n", errno); goto FINISH; } FINISH: free(csock); return 0; }
+4
source share
1 answer
 #include <sys/types.h> #include <unistd.h> pid_t pid=fork(); if(pid<0) exit(EXIT_FAILURE); //see no goto else if(pid>0){ //this is parent process, exit now exit(EXIT_SUCCESS); // again no goto } else{ //this is child or daemon unmask(); pid_t childid = setsid(); while(true){ myTask(); //Run the Process sleep(60); } }

Ok, I studied your program and made changes. Here's what your code should basically look like.

  using namespace std; using namespace boost; #define CHECK_THROW(condtion, code) if(condition) throw code void *SocketHandler(void *); int OpenSockets(); int main(int argv, char **argc) { try{ pid_t pid = fork(); CHECK_THROW(pid<0, -5); if(pid==0) { //this is child or daemon mode_t oldMask, newMask; oldMask=unmask(newMask); pid_t childid = setsid(); int hsock = OpenSocket(); CHECK_THROW(listen(hsock, 10) == -1, -4); addr_size = sizeof(sockaddr_in); while (true) { printf("waiting for a connectionn\n"); csock = (int *) malloc(sizeof(int)); *csock = accept(hsock, (sockaddr *) & sadr, &addr_size); CHECK_THROW(*csock!=-1, -7); printf("---------------------nReceived connection from %s\n", inet_ntoa(sadr.sin_addr)); pthread_t thread_id = pthread_create(&thread_id, 0, &SocketHandler, (void *) csock); pthread_detach(thread_id); } } } catch(int ierror) { switch(ierror) { case -4: fprintf(stderr, "Error listening %dn", errno); break; case -7: fprintf(stderr, "Error accepting %dn", errno); break; } } } int OpenSockets() { // Create your socket and return the socket handle from this function } void *SocketHandler(void *lp){ /*blah blah */ }
+1
source

Source: https://habr.com/ru/post/1502740/

More articles:


All Articles