据我所知，我正在做我被告知的一切。
命令行中的命令“ shutdown -P now”完全符合我的要求-立即关闭计算机。但是，使用该命令作为cron作业绝不会发生。
我只希望它在星期一至星期五的晚上8:30关闭，然后在9:30 pm和10:30 pm关闭。所以这就是我的工作；
我键入“ crontab -e”，并将其添加到文件的底部：
30 20,21,22 * * 1-5 shutdown -P now
我按CTRL + O来“保存”它，然后按CTRL + X退出。我在提示符下收到“ crontab：安装新的crontab”消息。
但是晚上8:30到来，没有关机。也不在9：30p或10:30 pm。
编辑：浏览此处提供的列表； CronJob not running
我在“测试cron正在工作”时停止了。我输入命令
* * * * * /bin/echo "cron works" >> /tmp/file
我得到了错误
Apps: command not found
在Google中搜索此错误不会显示任何相关信息。
此外，我终于能够看到（由于链接）从哪里获取消息日志输出-我在Linux Mint中（应该提到），所以我需要Ubuntu的方式来找到日志输出。关闭命令似乎正在运行，并且唯一的“错误”消息是“未安装MTA”，（从我刚刚阅读的内容来看）该消息仅用于通过电子邮件发送输出。否则，似乎没有任何明显的错误消息...有人可以对此有所了解吗？
domarius@Domarius-LinuxMint ~ $ grep CRON /var/log/syslog
Aug 3 08:17:01 Domarius-LinuxMint CRON[3259]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 09:17:01 Domarius-LinuxMint CRON[3876]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 10:17:01 Domarius-LinuxMint CRON[4122]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 11:17:01 Domarius-LinuxMint CRON[4349]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 12:17:01 Domarius-LinuxMint CRON[4719]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 13:17:01 Domarius-LinuxMint CRON[5028]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 14:17:01 Domarius-LinuxMint CRON[5317]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 15:17:01 Domarius-LinuxMint CRON[5933]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 16:17:01 Domarius-LinuxMint CRON[7083]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 20:26:38 Domarius-LinuxMint cron[1089]: (CRON) INFO (pidfile fd = 3)
Aug 3 20:26:38 Domarius-LinuxMint cron[1089]: (CRON) INFO (Running @reboot jobs)
Aug 3 20:30:01 Domarius-LinuxMint CRON[2670]: (root) CMD (shutdown -P now "Shutting down...")
Aug 3 20:30:01 Domarius-LinuxMint CRON[2671]: (domarius) CMD (/sbin/shutdown -p now)
Aug 3 20:30:01 Domarius-LinuxMint CRON[2669]: (CRON) info (No MTA installed, discarding output)
Aug 3 20:30:01 Domarius-LinuxMint CRON[2668]: (CRON) info (No MTA installed, discarding output)
Aug 3 21:17:01 Domarius-LinuxMint CRON[3058]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Aug 3 21:30:01 Domarius-LinuxMint CRON[3232]: (domarius) CMD (/sbin/shutdown -p now)
Aug 3 21:30:01 Domarius-LinuxMint CRON[3233]: (root) CMD (shutdown -P now "Shutting down...")
Aug 3 21:30:01 Domarius-LinuxMint CRON[3231]: (CRON) info (No MTA installed, discarding output)
Aug 3 21:30:01 Domarius-LinuxMint CRON[3230]: (CRON) info (No MTA installed, discarding output)
Aug 3 22:17:01 Domarius-LinuxMint CRON[3515]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
答案 0 :(得分：0)
通常在public class MessagingService extends FirebaseMessagingService{
private static final String TAG = "MyFirebaseMsgService";
private PreferenceManager preferenceManager = null;
private static int MY_NOTIFICATION_ID = 101;
Bitmap bitmap;
private static int count = 0;
NotificationManager notificationManager = null;
@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
// ...
preferenceManager = PreferenceManager.getInstance(this);
notificationManager =
(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
// Check if message contains a data payload.
if (remoteMessage.getData().size() > 0) {
String title = remoteMessage.getData().get("title");
String body = remoteMessage.getData().get("body");
String message = remoteMessage.getData().get("message");
String clickAction = remoteMessage.getData().get("click_action");
PendingIntent pendingIntent = null;
if(clickAction.equals("new request")){
Intent myIntent = new Intent(this, HomeActivity.class);
myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
myIntent.putExtra("title",title);
myIntent.putExtra("message",message);
myIntent.putExtra("body",body);
pendingIntent = PendingIntent.getActivity(
this,
0,
myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
}else if(clickAction.equals("new action")){
Intent myIntent = new Intent(this, ActionActivity.class);
myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
//fetching data from push notification
String amount = remoteMessage.getData().get("amount");
String status = remoteMessage.getData().get("status");
String persons = remoteMessage.getData().get("persons");
String user_id = remoteMessage.getData().get("user_id");
String id = remoteMessage.getData().get("id");
pendingIntent = PendingIntent.getActivity(
this,
0,
myIntent, PendingIntent.FLAG_ONE_SHOT);
//check whether app is running or not
if (Helper.isAppRunning(this, "com.imtiaz.testapp")) {
//notificationManager.cancelAll();
Intent intentNotification = new Intent();
intentNotification.setAction("com.imtiaz.testapp.messagingService");
intentNotification.putExtra("checkedin",checkedInItemModel);
intentNotification.putExtra("type","check_in");
sendBroadcast(intentNotification);
} else {
// App is not running
}
}else if(clickAction.equals("checkedout")){
Intent myIntent = new Intent(this, HomeActivity.class);
myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
myIntent.putExtra("title",body);
myIntent.putExtra("message",message);
myIntent.putExtra("body",title);
pendingIntent = PendingIntent.getActivity(
this,
0,
myIntent, PendingIntent.FLAG_ONE_SHOT);
//save checked in model data
preferenceManager.setIsBookingEnabled(false);
preferenceManager.setCheckedInData(null);
//check whether app is running or not
if (Helper.isAppRunning(this, "com.imtiaz.testapp")) {
notificationManager.cancelAll();
Intent intentNotification = new Intent();
intentNotification.setAction("com.imtiaz.testapp.messagingService");
intentNotification.putExtra("type","check_out");
intentNotification.putExtra("body",body);
intentNotification.putExtra("message",message);
intentNotification.putExtra("title",title);
sendBroadcast(intentNotification);
} else {
// App is not running
}
}
Notification myNotification = new NotificationCompat.Builder(this)
.setContentTitle(title)
.setContentText(body)
.setTicker("Notification!")
.setWhen(System.currentTimeMillis())
.setContentIntent(pendingIntent)
.setDefaults(Notification.DEFAULT_SOUND)
.setAutoCancel(true)
.setSmallIcon(R.drawable.testapp)
.build();
MY_NOTIFICATION_ID ++;
notificationManager.notify(MY_NOTIFICATION_ID, myNotification);
}
if (remoteMessage.getNotification() != null) {
Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
}
}
private Bitmap getCircleBitmap(Bitmap bitmap) {
final Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
final Canvas canvas = new Canvas(output);
final int color = Color.RED;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawOval(rectF, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
bitmap.recycle();
return output;
}}
中检查您的cron日志。很有可能是路径问题，请使用此功能。
/var/log/cron答案 1 :(得分：0)
在我的问题被无意中打败，并提供了许多无法正常工作的链接后，我在Linux Mint论坛上获得了我所需要的帮助-秘密是使用sudo命令编辑crontab； “ sudo crontab -e”和其他有用的信息在这篇文章中。 https://forums.linuxmint.com/viewtopic.php?f=47&t=275029&p=1507982#p1507982
答案 2 :(得分：0)
sudo vim / etc / crontab
00 22 * * *根/ sbin / poweroff
答案 3 :(得分：0)
04/13/2021 更新：
运行：Ubuntu 20
我用来做 cronjob 的步骤在下午 3 点 45 分关闭计算机
$ sudo crontab -e45 13 * * 1-5 sudo shutdown -h now