2012-01-27 59 views
1

程序關閉,我有以下libev代碼:C/libev:當事件被觸發

#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; 
} 

一切工作就好了(幾乎)。編譯:gcc file.c -lev,並運行./a.out。然後寫入./a.out正在偵聽的套接字:echo "gobblydeegook" | nc -U /tmp/mysocket

Hello按預期出現在控制檯上。

但程序調用該事件,然後繼續打印「hello」ad-infinitum!我希望它繼續監視這個unix套接字的寫入。這個怎麼做?

回答

2

當有數據要在套接字上讀取時,事件被調用。既然你不是從套接字中刪除數據,只是打印「你好」,事件再次被調用來處理數據。

+0

嗯。這非常有趣,謝謝。我嘗試讀取數據(查看更新後的帖子,但我一直收到一個「recv:Invalid argument」錯誤 – Eamorr 2012-01-27 15:35:41

+0

libev也在套接字上調用相同的事件來處理錯誤,就像它關閉時一樣。該事件再次被調用,此時,您嘗試在一個封閉的套接字上進行接收。 – Ioan 2012-01-27 15:39:57

+0

oh right ...我認爲我瞭解你,你知道有什麼辦法可以抵制這個嗎? – Eamorr 2012-01-27 15:41:50

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