Documented in Volume 1 of the UNIX Programmers Manual.
% at 8am jan 24 cshscript
will cause the contents of cshscript to be invoked reasonably soon
after 0800 on Jan 24 of the present year.
% at 1530 fr week cshscript
will cause cshscript to be invoked a week from the coming Friday.
% at 2330 jul 25
batchproc >& batchtrace
CTRL-D
will fire up "batchproc", whatever it is, at 2330 on July 25. Standard
and error output will be placed into the file "batchtrace" in the
current working directory.
NOTE:
1) At some installations, the 'at' queue is contained in /usr/spool/at with
the queue interrogated every quarter hour, on the quarter hour.
2) at has standard UNIX protection against run-away processes (almost none).
3) The output gets thrown away unless redirected.
4) To remove an at run, change directories to '/usr/spool/at'. Then identify
the file containing the unwanted run by doing an ls -l and seeing
your name. Once identified, do a cat into it (to nullify its contents).
This functionally kills it (this is necessary because you do not have
write permission into the directory).
BUGS:
As of March, 1984:
Description:
(1) at's date algorithm is wrong .07% of the time: it thinks the julian
date of March 1st in leap years is 60, not 61.
(2) if you try to queue more than 100 jobs at a single time, it loops
(patiently looking for an unused 2-digit sequence)