.\" $FreeBSD$
.Dd June 22, 2015
.Dt ATRUN 8
.Os
.Sh NAME
.Nm atrun
.Nd run jobs queued for later execution
.Sh SYNOPSIS
.Nm atrun
.Op Fl l Ar load_avg
.Op Fl d
.Sh DESCRIPTION
.Nm Atrun
runs jobs queued by
.Xr at 1 .
.Pp
The system
.Xr crontab 5
file
.Pa /etc/crontab
must contain the line
.Bd -literal
*/5     *       *       *       *       root    /usr/libexec/atrun
.Ed
.Pp
so
.Nm
is invoked every five minutes.
.Pp
At every invocation,
.Nm
starts all the jobs in the lowercase queues whose start
time has elapsed.
In addition, if the load average over the last minute was less than
the specified limit, then a maximum of one batch job (denoted by the
uppercase queues) is started.
.Pp
Before starting a job,
.Nm
checks the status of its owner's account with
.Xr pam 3
and refuses to run the job if the account is unavailable,
e.g., locked out or expired.
.Sh OPTIONS
.Bl -tag -width indent
.It Fl l Ar load_avg
Specify a limiting load factor, over which batch jobs should
not be run, instead of the default of 1.5 * number of active CPUs.
.It Fl d
Debug; print error messages to standard error instead of using
.Xr syslog 3 .
.El
.Sh WARNINGS
For
.Nm
to work, a
.Xr cron 8
daemon must be running
.Nm
periodically.
.Sh FILES
.Bl -tag -width /etc/pam.d/atrun -compact
.It Pa /etc/pam.d/atrun
.Xr pam.conf 5
configuration file for
.Nm
.It Pa /var/at/jobs
Directory containing job files
.It Pa /var/at/spool
Directory containing output spool files
.El
.Sh SEE ALSO
.Xr at 1 ,
.Xr crontab 1 ,
.Xr pam 3 ,
.Xr syslog 3 ,
.Xr crontab 5 ,
.Xr pam.conf 5 ,
.Xr cron 8
.Sh BUGS
The functionality of
.Nm
should be merged into
.Xr cron 8 .