at -V (return code: 0)
at version 3.1.18
Please report bugs to the Debian bug tracking system (http://bugs.debian.org/)
or contact the maintainers (at@packages.debian.org).
at --help (return code: 1)
at: invalid option -- '-'
Usage: at [-V] [-q x] [-f file] [-mMlbv] timespec ...
at [-V] [-q x] [-f file] [-mMlbv] -t time
at -c job ...
atq [-V] [-q x]
at [ -rd ] job ...
atrm [-V] job ...
batch