LINUX下调节屏幕亮度(Intel核显)-续

    之前写的博文里已经实现了屏幕亮度的调节（http://jianshusoft.blog.51cto.com/2380869/810780），但是毕竟没有和Fn快捷键绑定，略有遗憾。所以写个小程序让键盘来控制亮度。原理很简单，监控acpi_video0目录下的brightness文件，如果有改动，则修改到intel_backlight下的brightness。而且把密码隐藏在了程序里，不用担心shell脚本会漏露密码了。

#include <stdlib.h>
#include <unistd.h>


int main()
{
    int fd = inotify_init();
    if(fd == -1){
        printf("inotify_init error!\n");
        exit(-1);
    }

    system("echo \"这里输入密码\" | sudo -S chmod 777 /sys/class/backlight/intel_backlight/brightness");

    inotify_add_watch(fd, "/sys/class/backlight/acpi_video0/brightness", IN_MODIFY);

    inotify_event buf[1];
    int size = sizeof(inotify_event) * 1;

    int last = 0;
    char brightness[10];
    while(read(fd, buf, size)){
        FILE *source = fopen("/sys/class/backlight/acpi_video0/brightness", "r");
        if(fgets(brightness, 10, source) != NULL){
            fclose(source);

            int temp = (atoi(brightness) + 1) * 4882 / 10;
            if(last != temp ){
                last = temp;
                sprintf(brightness, "%d", temp);
                FILE *file = fopen("/sys/class/backlight/intel_backlight/brightness", "w");
                fputs(brightness, file);
                fclose(file);

                printf("changed %s \n", brightness);
            }

            //每次按键会修改三次，所以忽略后两次
            //read(fd, buf, size);
            //read(fd, buf, size);
        }

    }

    int result = close(fd);
    printf("%d", result);
}