at

The at utility reads commands from standard input and groups them together as an at-job, to be executed at a later time.

The at-job is executed in a separate invocation of the shell, running in a separate process group with no controlling terminal, except that the environment variables, current working directory, file creation mask (see umask(1)), and system resource limits (for sh and ksh only, see ulimit(1)) in effect when the at utility is executed is retained and used when the at-job is executed.

When the at-job is submitted, the at_job_id and scheduled time are written to standard error. The at_job_id is an identifier that is a string consisting solely of alphanumeric characters and the period character. The at_job_id is assigned by the system when the job is scheduled such that it uniquely identifies a particular job.

User notification and the processing of the job's standard output and standard error are described under the -m option.

Users are permitted to use at and batch (see below) if their name appears in the file /usr/lib/cron/at.allow. If that file does not exist, the file /usr/lib/cron/at.deny is checked to determine if the user should be denied access to at. If neither file exists, only a user with the solaris.jobs.user authorization is allowed to submit a job. If only at.deny exists and is empty, global usage is permitted. The at.allow and at.deny files consist of one user name per line.

cron and at jobs are not be executed if the user's account is locked. Only accounts which are not locked as defined in shadow(5) will have their job or process executed.

batch

The batch utility reads commands to be executed at a later time.

Commands of the forms:

/usr/bin/batch [-p project]
/usr/xpg4/bin/batch [-p project]

are respectively equivalent to:

/usr/bin/at -q b [-p project] now
/usr/xpg4/bin/at -q b -m [-p project] now

where queue b is a special at queue, specifically for batch jobs. Batch jobs are submitted to the batch queue for immediate execution. Execution of submitted jobs can be delayed by limits on the number of jobs allowed to run concurrently. See queuedefs(5).

at

Example 1 Typical Sequence at a Terminal

This sequence can be used at a terminal:

$ at −m 0730 tomorrow
sort < file >outfile
<EOT>

Example 2 Redirecting Output

This sequence, which demonstrates redirecting standard error to a pipe, is useful in a command procedure (the sequence of output redirection specifications is significant):

$ at now + 1 hour <<!
diff file1 file2 2>&1 >outfile | mailx mygroup

Example 3 Self-rescheduling a Job

To have a job reschedule itself, at can be invoked from within the at-job. For example, this "daily-processing" script named my.daily runs every day (although crontab is a more appropriate vehicle for such work):

# my.daily runs every day
at now tomorrow < my.daily
daily-processing

Example 4 Various Time and Operand Presentations

The spacing of the three portions of the "C" locale timespec is quite flexible as long as there are no ambiguities. Examples of various times and operand presentations include:

at 0815am Jan 24
at 8 :15amjan24
at now "+ 1day"
at 5 pm FRIday
at '17
	utc+
	30minutes'

batch

Example 5 Typical Sequence at a Terminal

This sequence can be used at a terminal:

$ batch
sort <file >outfile
<EOT>

Example 6 Redirecting Output

This sequence, which demonstrates redirecting standard error to a pipe, is useful in a command procedure (the sequence of output redirection specifications is significant):

$ batch <<!
diff file1 file2 2>&1 >outfile | mailx mygroup
!

/usr/bin/at

/usr/xpg4/bin/at

/usr/bin/batch

/usr/xpg4/bin/batch