выполнять команды позже (execute commands at a later time)
Использование в приложениях (Application usage)
The format of the at command line shown here is guaranteed only
for the POSIX locale. Other cultures may be supported with
substantially different interfaces, although implementations are
encouraged to provide comparable levels of functionality.
Since the commands run in a separate shell invocation, running in
a separate process group with no controlling terminal, open file
descriptors, traps, and priority inherited from the invoking
environment are lost.
Some implementations do not allow substitution of different
shells using SHELL. System V systems, for example, have used the
login shell value for the user in /etc/passwd. To select
reliably another command interpreter, the user must include it as
part of the script, such as:
$ at 1800
myshell myscript
EOT
job ... at ...
$
