Re: crontab(1) using stdin

On Thu, Oct 31, 2024 at 12:35:01AM +0100, Steffen Nurpmeso wrote:
> наб wrote in
>  <q2pxxf2jv42trd53f3vu6n6656i2oxsne4p4pefirzq52mru7j@tarta.nabijaczleweli\
>  .xyz>:
>  |You can still write this portably:
>  |  echo crontab > ./-
>  |  crontab - < -
>  |  rm -
>  |unideal, sure, but.
> OpenIndiana says
>   #?1|oi-2024:steffen$ crontab -
>   crontab: can't open your crontab file.
Regardless of the school this subscribes to it should work.

I tried to install openindiana to test but the images don't work,
but if it's similar to the illumos gate crontab then I don't see why it
wouldn't
        } else {
                if (argc == 0)
                        copycron(stdin);
                else if (seteuid(getuid()) != 0 || (fp = fopen(argv[0], "r"))
                    == NULL)
                        crabort(BADOPEN);
                else {
                        seteuid(0);
                        copycron(fp);
                }
        }
(BADOPEN is "can't open your crontab file.")

Beside something funny like, say, special - handling?
But unclear why the fopen would fail then or what it'd be.
What about... "crontab -- - < -"?

-----BEGIN PGP SIGNATURE-----
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=gAc9
-----END PGP SIGNATURE-----