At and at in Linux

At and at in Linux

For at, its whitelist and blacklist are/etc/. allow and/etc/. deny: Generally, the writing rule is a line of one account. If it is empty, only the root account can be used.

The main format is:

At [-mldv] Time

At-c work number

Interpretation of its parameters:

(1)-m when at is finished, even if no information is output, notify the user via email that the work has been completed.

(2)-l and at-l are equivalent to atq, listing all the at Schedules of the current user on the system

(3)-d and at-d are equivalent to atrm. You can cancel a job in the at scheduling, such as at-d 1.

(4)-v can use an obvious time format to list the work list in the at schedule.

(5)-c can list the actual instructions for the subsequent work.

For time, that is, the time format, we can use the following format:

(1) HH: MM. For example, indicates that it is performed at HH: MM today. If it has exceeded this time, it indicates that HH: MM is executed tomorrow.

(2) HH: MM YYYY-MM-DD such as, it is forced to work at a special time of a month.

(3) HH: MM [am | pm] [Month] [Date] For example, 04 pm March 17 is also enforced at a certain time point of a Month or day of a certain year.

(4) HH: MM [am | pm] + [number] [minutes | hours | days | weeeks] For example, now + 3 days, it can be executed only after a certain time point.

Enter at time and press enter to enter the at command editing interface. Note that Ctrl + D is used to enter an <EOT>.

We use at-l to display the number of tasks. We use the at-d task number to delete a task. We use the at-c task number to view the content of a task.

Start the service and use/etc/init. d/atd start. You can use chkconfig atd on to set automatic start upon startup.