how to fix "you do not have permission" error when trying to run the "at" command

when trying to run the at(1) command, e.g.:

idox ~ $ at 'now + 5 minutes'

one may receive the error message:

at: you do not have permission to use this program

the fix is to add one’s user name to the at permissions file. as root, do:

echo dave >>/var/at/at.allow

if one still has problems, check for the presence of a /var/at/at.deny file. man(1) explains it in detail.

that’s all folks!
Sun Nov 5 09:03:05 PST 2017