atd command in Linux with examples

atd is a job scheduler daemon that runs jobs scheduled for later execution. These jobs are one-time task(not recurring) at a specific time scheduled using ‘at’ or ‘batch’ utility.

Syntax:

atd [-l load_avg] [-b batch_interval] [-d] [-f] [-s]

Options:

• -l : Specifies a limiting load factor, over which batch jobs should not be run, instead of the compile-time choice of 1.5.
• -b : Specify the minimum interval in seconds between the start of two batch jobs (60 default).
• -d : Debug; print error messages to standard error instead of using syslog(3). This option also implies -f.
• -f : Run atd in the foreground.
• -s : Process the at/batch queue only once. This is primarily of use for compatibility with old versions of at; atd -s is equivalent to the old atrun command.

Starting atd:

• To start atd in the current session, use below command:

  $ service atd start 

• To start atd automatically at boot time, use below command:

  $ chkconfig atd on 

• While using ‘at’ utility, the following issue can be seen:

  

  It means that atd is not running and needs to be started.

Stopping atd:

• To stop atd in the current session, use below command:

  $ service atd stop 

• To disable atd from starting at boot time, use below command:

  $ chkconfig atd off 

Restarting atd: To restart atd, use below command.

$ service atd restart 

Checking atd status: To determine if atd is running or not, use below command:

$ service atd status 

• If atd is running, status will be “active”:

  

• If atd is not running, status will be “inactive”:
  

  Example: