This works:
$ echo "notify-send HELLO" | at now
This doesn't:
$ at now < echo "notify-send HELLO"
It says 'file or directory not found".
I understand there's a -f
option to this command, which with which i can supply the file to be executed at a given moment.
So this got me thinking... in general, how do i know for which parameter the redirection operators supply the value?
foo | bar
andbar < foo
are equivalent. They are not.