bug#62497: maybe date -f <directory> should generate an error

[Sylvestre Ledru]

Hello

The usual case is:

$ echo "2023-03-27 08:30:00" > dates.txt
$ echo "2023-04-01 12:00:00" >> dates.txt

$ /usr/bin/date -f dates.txt
Mon Mar 27 08:30:00 CEST 2023
Sat Apr 1 12:00:00 CEST 2023

If done on a non existing file, we get:

$ date -f non-existing
/usr/bin/date: non-existing: No such file or directory

Maybe it should do the same on a directory:

 $ /usr/bin/date -f /
doesn't show anything and return 0

Cheers,
Sylvestre