C / LIBEV: il programma si chiude quando l'evento viene attivato

Question

Ho il seguente codice LIBEV:

#include <ev.h>
#include <stdio.h>
#include <errno.h>
#include <sys/socket.h>
#include <resolv.h>
#include <string.h>
#include <stdlib.h>
#include <sys/un.h>
#include <netinet/in.h>

ev_io stdin_watcher;

static void cb(EV_P_ ev_io *w, int revents){
        puts ("hello");

        //read file here - suggestion due to Ioan
        #define BUF_LEN 10
        char buf[BUF_LEN];
        memset(buf,0,BUF_LEN);
        int byte_read;
        while( (byte_read = recv(w->fd,buf,BUF_LEN-1,0)) > 0) {
                printf("len: %i: %s",byte_read,buf);
                memset(buf,0,BUF_LEN);
        }


        if(-1 == byte_read && EAGAIN != errno) {
            perror("recv");
        }
        close(w->fd);

        //ev_io_stop (EV_A_ w);
        //ev_unloop (EV_A_ EVUNLOOP_ALL);
}


int main (void){
        struct ev_loop *loop = ev_default_loop (0);
        int len;

        int sd;
        sd=socket(AF_UNIX,SOCK_STREAM,0);

        struct sockaddr_un address;
        //memset(&address,0,sizeof(address));
        address.sun_family=AF_UNIX;
        strcpy(address.sun_path,"/tmp/mysocket");
        unlink(address.sun_path);
        len=strlen(address.sun_path)+sizeof(address.sun_family);

        int x=bind(sd,(struct sockaddr*)&address,sizeof(address));
        printf("%d\n",x);
        listen(sd,5);

        ev_io_init(&stdin_watcher,cb,sd,EV_READ);
        ev_io_start(loop,&stdin_watcher);

        ev_loop (loop, 0);

        // unloop was called, so exit
        return 0;
}

.

Tutto funziona bene (quasi).Compilazione: gcc file.c -lev, ed esegui ./a.out.Quindi scrivi sulla presa che ./a.out sta ascoltando: echo "gobblydeegook" | nc -U /tmp/mysocket.

Ciao appare sulla console come previsto.

Ma il programma chiama l'evento e quindi continua a stampare "Hello" ad-Infinitum!Voglio continuare a monitorare questa presa Unix per scritture.Come fare questo?

Answer 1

The event gets called when there is data to be read on the socket. Since you aren't removing the data from the socket, just printing "hello", the event is called again for you to handle the data.