Zeroplex 生活隨筆

登入 Ubuntu 時，常會看到最底下會有一行字，提醒你主機是否需要重新開機：

Welcome to Ubuntu 16.04.6 LTS (GNU/Linux 4.4.0-142-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

0 packages can be updated.
0 updates are security updates.


*** System restart required ***

追了一陣子，才知道判斷的方法非常簡單，只要到 /var/run 目錄下檢查是否有「reboot-required」的檔案即可。

例如：

$ ls /var/run
acpid.pid      crond.reboot         initctl         log          motd.dynamic          resolvconf         snapd.socket  udev
acpid.socket   dbus                 initramfs       lvm          mount                 rsyslogd.pid       sshd          unattended-upgrades.lock
agetty.reload  dhclient.enp0s3.pid  init.upgraded   lvmetad.pid  mysqld                screen             sshd.pid      user
atd.pid        dmeventd-client      irqbalance.pid  lxcfs        network               sendsigs.omit.d    sudo          utmp
blkid          dmeventd-server      iscsid.pid      lxcfs.pid    reboot-required       shm                systemd       uuidd
crond.pid      grub                 lock            mdadm        reboot-required.pkgs  snapd-snap.socket  tmpfiles.d    xtables.lock

就這樣，沒了。