atrm job [job ...]
|executes commands at a specified time;
|lists the user's pending jobs, unless the user is the superuser; in that case, everybody's jobs are listed;
|executes commands when system load levels permit; in other words, when the load average drops below 1.5 times number of active CPUs, or the value specified in the invocation of atrun.
The at utility allows some moderately complex time specifications. It accepts times of the form HHMM or HH:MM to run a job at a specific time of day. (If that time is already past, the next day is assumed.) As an alternative, the following keywords may be specified: midnight, noon, or teatime (4pm) and time-of-day may be suffixed with AM or PM for running in the morning or the evening. The day on which the job is to be run may also be specified by giving a date in the form month-name day with an optional year, or giving a date of the forms DD.MM.YYYY, DD.MM.YY, MM/DD/YYYY, MM/DD/YY, MMDDYYYY , or MMDDYY. The specification of a date must follow the specification of the time of day. Time can also be specified as: [ now] + count time-units, where the time-units can be minutes, hours, days, weeks, months or years and at may be told to run the job today by suffixing the time with today and to run the job tomorrow by suffixing the time with tomorrow.
For example, to run a job at 4pm three days from now, use at, to run a job at 10:00am on July 31, use at and to run a job at 1am tomorrow, use at.
utility also supports the
time format (see
commands are read from standard input or the file specified
The superuser may use these commands in any case. For other users, permission to use at is determined by the files /var/at/at.allow and /var/at/at.deny.
If the file /var/at/at.allow exists, only usernames mentioned in it are allowed to use at. In these two files, a user is considered to be listed only if the user name has no blank or other characters before it on its line and a newline character immediately after the name, even at the end of the file. Other lines are ignored and may be used for comments.
If /var/at/at.allow does not exist, /var/at/at.deny is checked, every username not mentioned in it is then allowed to use at.
If neither exists, only the superuser is allowed use of at. This is the default configuration.
|Use the specified queue. A queue designation consists of a single letter; valid queue designations range from a to z and A to Z. The c queue is the default for at and the E queue for batch. Queues with higher letters run with increased niceness. If a job is submitted to a queue designated with an uppercase letter, it is treated as if it had been submitted to batch at that time. If atq is given a specific queue, it will only show jobs pending in that queue.
|Send mail to the user when the job has completed even if there was no output.
|Read the job from file rather than standard input.
|With no arguments, list all jobs for the invoking user. If one or more job numbers are given, list only those jobs.
Is an alias for
(this option is deprecated; use
|Is an alias for batch.
|For atq, shows completed but not yet deleted jobs in the queue; otherwise shows the time the job will be executed.
|Cat the jobs listed on the command line to standard output.
|Remove the specified jobs.
Specify the job time using the time format.
The argument should be in the form
[[CC ]YY]MM DD hh mm [. file ...]where each pair of letters represents the following:
|The first two digits of the year (the century).
|The second two digits of the year.
|The month of the year, from 1 to 12.
|the day of the month, from 1 to 31.
|The hour of the day, from 0 to 23.
|The minute of the hour, from 0 to 59.
|The second of the minute, from 0 to 60.
If the CC and YY letter pairs are not specified, the values default to the current year. If the file ... letter pair is not specified, the value defaults to 0.
|directory containing job files
|directory containing output spool files
|allow permission control
|deny permission control
|job-creation lock file
The at and batch utilities as presently implemented are not suitable when users are competing for resources. If this is the case, another batch system such as nqs may be more suitable.
Specifying a date past 2038 may not work on some systems.
|August 11, 2018
|UNIX has been evolving feverishly for close to 30 years, sort of like bacteria in a cesspool — only not as attractive
|— John Levine, "Unix for Dummies"