通过select较高效的捕获和处理鼠标键盘事件

select监听这些文件描述符的状态，若有一个发生变化则返回，否则阻塞。

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1. #include <stdio.h>      
2. #include <stdlib.h>      
3. #include <linux/input.h>      
4. #include <fcntl.h>      
5. #include <sys/time.h>      
6. #include <sys/types.h>      
7. #include <sys/stat.h>      
8. #include <unistd.h>      
9.   
10. int main(int argc,char **argv)      
11. {      
12.     int fd, retval;      
13.     char buf[6];      
14.     fd_set readfds;      
15.     struct timeval tv;      
16.   
17.     // 打开鼠标设备      
18.     fd = open( "/dev/input/mice", O_RDONLY );      
19.     // 判断是否打开成功      
20.     if(fd<0) {      
21.         printf("Failed to open \"/dev/input/mice\".\n");      
22.         exit(1);      
23.     } else {      
24.         printf("open \"/dev/input/mice\" successfuly.\n");      
25.     }      
26.       
27.     int fd_kb;       
28.     struct input_event event_kb;    
29.     fd_kb = open("/dev/input/event1", O_RDONLY); //键盘输入    
30.     if(fd_kb <= 0)    
31.     {    
32.             printf("open device error\n");    
33.             return 0;    
34.     }  
35.       
36.     int fd_mouse;      
37.     struct input_event event_mouse;         
38.     fd_mouse = open("/dev/input/event4", O_RDONLY); //鼠标输入    
39.     if(fd_mouse <= 0)    
40.     {    
41.             printf("open device error\n");    
42.             return 0;    
43.     }  
44.       
45.       
46.     while(1) {      
47.         // 设置最长等待时间      
48.         tv.tv_sec = 5;      
49.         tv.tv_usec = 0;      
50.       
51.         FD_ZERO( &readfds );      
52.         FD_SET( fd, &readfds );      
53.         FD_SET( fd_kb, &readfds );   
54.         FD_SET( fd_mouse, &readfds );   
55.       
56.         int max=fd>fd_kb?(fd>fd_mouse?fd:fd_mouse):(fd_kb>fd_mouse?fd_kb:fd_mouse);  
57.           
58.         retval = select( max+1, &readfds, NULL, NULL, &tv );//有文件描述符的状态发生变化（变为可读）或者超时和错误就返回，否则就阻塞      
59.         if(retval==0) {      
60.             printf( "Time out!\n" );      
61.         }else if(retval<0){  
62.             printf( "error!\n" );   
63.         }else{                      //判断是哪个文件描述符的状态发生了变化，进行处理即可  
64.           
65.             //鼠标位置  
66.             if(FD_ISSET(fd,&readfds))   
67.             {      
68.                 // 读取鼠标设备中的数据      
69.                 if(read(fd, buf, 6) <= 0) {      
70.                     continue;      
71.                 }      
72.                 // 打印出从鼠标设备中读取到的数据      
73.                 printf("Button type = %d, X = %d, Y = %d, Z = %d\n", (buf[0] & 0x07), buf[1], buf[2],   buf[3]);      
74.             }    
75.               
76.             //键盘点击  
77.             if(FD_ISSET(fd_kb,&readfds))   
78.             {      
79.                 if(read(fd_kb, &event_kb, sizeof(event_kb)) == sizeof(event_kb))    
80.                 {    
81.                     if (event_kb.type == EV_KEY)    
82.                     {    
83.                         //if (event_kb.value == 0 || event_kb.value == 1)//1表示按下，0表示释放，会检测到两次    
84.                         if (event_kb.value == 1)//键按下    
85.                         {    
86.                                 //printf("key %d %s\n", event_kb.code, (event_kb.value) ? "Pressed" : "Released");    
87.                                 if(event_kb.code == KEY_ESC)    
88.                                         break;    
89.                                 if(event_kb.code == KEY_Q)    
90.                                     printf("q\n");                                     
91.                                 if(event_kb.code == KEY_W)    
92.                                     printf("w\n");      
93.                                 if(event_kb.code == KEY_E)    
94.                                     printf("e\n");      
95.                                 if(event_kb.code == KEY_R)    
96.                                     printf("r\n");      
97.                         }    
98.     
99.                     }    
100.                     
101.                 }       
102.             }    
103.               
104.             //鼠标点击  
105.             if(FD_ISSET(fd_mouse,&readfds))   
106.             {      
107.                 if(read(fd_mouse, &event_mouse, sizeof(event_mouse)) == sizeof(event_mouse))    
108.                 {                                       
109.                     if(event_mouse.type = EV_REL)    
110.                     {    
111.                         if(event_mouse.code == REL_WHEEL)           
112.                             printf("REL_WHEEL %d\n", event_mouse.value);//-1表示下滑，1表示上滑    
113.                     }       
114.          
115.                     if(event_mouse.code == BTN_LEFT && event_mouse.value==1)//左键按下，1表示按下，0表示释放。不然会检测到两次    
116.                         printf("left down: %d\n", event_mouse.code);    
117.                             
118.                     if(event_mouse.code == BTN_RIGHT && event_mouse.value==1)    
119.                         printf("right down: %d\n", event_mouse.code);    
120.                             
121.                     if(event_mouse.code == BTN_MIDDLE && event_mouse.value==1)    
122.                         printf("middle down: %d\n", event_mouse.code);    
123.   
124.                 }   
125.             }     
126.           
127.         }         
128.     
129.     }      
130.     close(fd);    
131.     close(fd_kb);   
132.     close(fd_mouse);      
133.     return 0;      
134. }   
135.   
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139.