service 文件格式
root@server01:~# systemctl cat atd.service
#/lib/systemd/system/atd.service
[Unit]
Description=Deferred execution scheduler
Documentation=man:atd(8)
After=remote-fs.target nss-user-lookup.target
[Service]
ExecStartPre=-find /var/spool/cron/atjobs -type f -name “=*” -not -newercc /run/systemd -delete
ExecStart=/usr/sbin/atd -f
IgnoreSIGPIPE=false
KillMode=process
Restart=on-failure
[Install]
WantedBy=multi-user.target
ls /usr/lib/systemd/system/*.target
[root@ip-172-31-14-7 ~]# systemctl get-default
multi-user.target
root@server01:~# systemctl mask ctrl-alt-del.target
进制重启