at.1 (2010 09)
a
at(1) at(1)
Redirect standard error to a pipe (useful in a shell procedure). Note that the sequence of the output
redirection specifications is significant. Standard error is redirected to where standard output is going;
standard output is redirected to a file; the original "standard output" (which now consists of the former
standard error) is piped to the mail program.
batch <<!! (sets eof temporarily to !!)
nroff input-file 2>&1 1> output-file | mail loginid
!!
Run a job contained in jobfile in the home directory at 5:00 a.m. next Tuesday:
at -f $HOME/jobfile 5am tuesday next week
Run the same job at 5:00 a.m. one week from next Tuesday (i.e., 2 Tuesdays in advance):
at -f $HOME/jobfile 5am tuesday + 2 weeks
Add a command to the file named
weekly-run in directory jobs in the home directory so that it
automatically reschedules itself every time it runs. This example reschedules itself every Thursday at
1900 (7:00 p.m.):
echo "sh $HOME/jobs/weekly-run" | at 1900 thursday next week
The following commands show several forms recognized by
at and include native language usage:
at 0815 Jan 24
at 8:15 Jan 24
at 9:30am tomorrow
at now + 1 day
at -f job 5 pm Friday
at 17:40 Tor. # in Danish
at 17h46 demain # in French
at 5:30 26. Feb. 1988 # in German
at 12:00 26-02 # in Finnish
WARNINGS
If the date argument begins with a number and the time argument is also numeric without a suffix, the
time argument should be a four-digit number that can be correctly interpreted as hours and minutes.
If you use both
next and +count within a single at command, the first operator is accepted and the trail-
ing operator is silently ignored.
If you use both
-t and time ... in the same command, the first specified is accepted and the second is
silently ignored.
If the FIFO used to communicate with
cron fills up, at is suspended until cron
has read sufficient mes-
sages from the FIFO to make room for the message
at is trying to write. This condition can occur if
at is
writing messages faster than
cron can process them or if cron is not executing.
Scheduled processes are run in the background. Any script file that calls itself will cause the user or the
system to run out of available processes.
If the execution-time request for a job duplicates the execution time of a currently scheduled job, the new
job time is set to the next available second.
at will not schedule jobs whose start time precedes the current Epoch (00:00:00 January 1, 1970 UTC).
at will not schedule jobs beyond the year 2037.
DEPENDENCIES
HP Process Resource Manager
If the optional HP Process Resource Management (PRM) software is installed and configured, jobs are
launched in the initial process resource group of the user that scheduled the job. The user’s initial group
is determined at the time the job is started, not when the job is scheduled. If the user’s initial group is
not defined, the job runs in the user default group (
PRMID=1). See prmconfig(1) for a description of how
to configure HP PRM, and prmconf (4) for a description of how the user’s initial process resource group is
determined.
AUTHOR
at was developed by AT&T and HP.
HP-UX 11i Version 3: September 2010 − 5 − Hewlett-Packard Company 5