直接通过event设备读取input_event键码

//compiler: gcc 4.3.2#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <fcntl.h>#include <sys/select.h>#include <sys/types.h>#include <sys/stat.h>#include <linux/input.h>#define DEV_ENENT  "/dev/input/event0"#define EVENT_STACK_SIZE 16struct input_event event_stack[EVENT_STACK_SIZE];int main(){ int iFd = -1; int iSize = 0; int i; int retval; fd_set rfds; iFd = open(DEV_ENENT, O_RDONLY | O_NONBLOCK); if(iFd < 0) {  perror(DEV_ENENT);  return -1; } while(1) {    FD_ZERO(&rfds);  FD_SET(iFd, &rfds);  retval = select(iFd + 1, &rfds, NULL, NULL, NULL);  if (retval == -1)  {   perror("select()");   continue;  }  else if (retval)   printf("Data is available now.\n");  else   continue;  iSize = read(iFd, event_stack, sizeof(event_stack));  if(iSize >= 0)  {   for(i = 0; i < iSize/sizeof(event_stack[0]); i++)    printf("type = %d\n  \     code = %d\n  \     value = %d\n",     event_stack[i].type,     event_stack[i].code,     event_stack[i].value);  }  else  {   perror(DEV_ENENT);  } } close(iFd); return 0;}