上传文件至 'test_file'

提交监听文件改变事件demo

test_file/makefile

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+test_file:test_file.cpp
+	g++ $^ -o $@ -levent

test_file/test_file.cpp

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+#include <iostream>
+#include <event2/event.h>
+#include <string.h>
+#include <thread>
+
+#ifdef _WIN32
+	
+#else
+	#include <signal.h>
+    
+    #include <unistd.h>
+    #include <sys/types.h>
+    #include <sys/stat.h>
+    #include <fcntl.h>
+#endif // !_WIN32
+
+using namespace std;
+
+void read_file(evutil_socket_t fd,short event,void *arg){
+    char buf[1024] = {0};
+    int len = read(fd,buf,sizeof(buf) - 1);
+    if(len > 0){
+        cout << buf << endl;  // 当有用户登录就会把 该信息打印出来 
+    }else {
+        cout << "." << endl;    
+        this_thread::sleep_for(500ms);
+    }
+    
+}
+
+int main(int agrc,char** agrv){
+#ifdef _WIN32
+	//初始化socket库
+	WSADATA wsa;
+	WSAStartup(MAKEWORD(2, 2), &wsa);
+#else 
+	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) { //忽略管道信号，发送数据给已关闭的socket，会飞掉！
+		return 1;
+	}
+#endif
+
+    event_config* conf = event_config_new();
+    event_config_require_features(conf,EV_FEATURE_FDS);
+    event_base *base = event_base_new_with_config(conf);
+    event_config_free(conf);
+
+    if(!base){
+        cerr << "event_base_new_with_config failed" <<endl;
+    }
+    int sock = open("/var/log/auth.log",O_RDONLY|O_NONBLOCK,0);
+    if(sock < 0){
+        cerr << "/var/log/auth.log open failde" << endl; 
+    }
+
+    lseek(sock,0,SEEK_END);
+
+    //监听文件数据
+    event* fev = event_new(base,sock,EV_READ|EV_PERSIST ,read_file,0);
+    event_add(fev,NULL);
+    
+    //进入事件主循环
+    event_base_dispatch(base);
+    event_free(fev);
+    event_base_free(base);
+   
+    return 0;
+
+}