Linux / Unix at command

About at Syntax Examples Related commands Linux / Unix main page About at Schedules a command to be ran at a particular time, such as a print job late at night. Syntax at executes commands at a specified time. atq lists the user's pending jobs, unless the user is the superuser; in that case, everybody's jobs are listed. The format of the output lines (one for each job) is: Job number, date, hour, job class. atrm deletes jobs, identified by their job number. batch executes commands when system load levels permit; in other words, when the load average drops below 1.5, or the value specified in the invocation of atrun. at [-c | -k | -s] [-f filename] [-q queuename] [-m] -t time [date] [-l] [-r] -c C shell. csh(1) is used to execute the at-job. -k Korn shell. ksh(1) is used to execute the at-job. -s Bourne shell. sh(1) is used to execute the at-job. -f filename Specifies the file that contains the command to run. -m Sends mail once the command has been run. -t time Specifies at what time you want the command to be ran. Format hh:mm. am / pm indication can also follow the time otherwise a 24-hour clock is used. A timezone name of GMT, UCT or ZULU (case insensitive) can follow to specify that the time is in Coordinated Universal Time. Other timezones can be specified using the TZ environment variable. The below quick times can also be entered: midnight - Indicates the time 12:00 am (00:00). noon - Indicates the time 12:00 pm. now - Indicates the current day and time. Invoking at - now will submit submit an at-job for potentially immediate execution. date Specifies the date you wish it to be ran on. Format month, date, year. The following quick days can also be entered: today - Indicates the current day. tomorrow - Indicates the day following the current day. -l Lists the commands that have been set to run. -r Cancels the command that you have set in the past. Examples at -m 01:35 < atjob =""> commands will be executed using /bin/csh job 1072250520.a at Wed Dec 24 00:22:00 2003 at -l = This command will list each of the scheduled jobs as seen below. 1072250520.a Wed Dec 24 00:22:00 2003 at -r 1072250520.a = Deletes the job just created. or atrm 23 = Deletes job 23. If you wish to create a job that is repeated you could modify the file that executes the commands with another command that recreates the job or better yet use the crontab command. Note: Performing just the at command at the prompt will give you an error "Garbled Time", this is a standard error message if no switch or time setting is given. From:http://www.computerhope.com/unix/uat.htm