Path: utzoo!attcan!uunet!nfsun!ditka!royko!simon!obdient!laidbak!stevea
From: stevea@laidbak.UUCP (Steve Alexander)
Newsgroups: comp.mail.uucp
Subject: Re: su uucp in crontabs/root ?
Keywords: root uucp crontab su
Message-ID: <2290@laidbak.UUCP>
Date: 2 May 89 18:02:20 GMT
References: <75@norsat.UUCP> <2008@egvideo.UUCP> <1524@auspex.auspex.com> <483@sequoia.UUCP>
Reply-To: stevea@laidbak.UUCP (Steve Alexander)
Distribution: na
Organization: Lachman Associates, Inc. Naperville, IL.
Lines: 18

In article <483@sequoia.UUCP> dewey@sequoia.UUCP (Dewey Henize) writes:
>Can someone who's looking at source or speaking from experience tell me, please,
>HOW they're told to?  Is there a signal that could be used?  It would seem the
>most 'unixy' thing, but I've not found it in any of our docs, and we don't have
>any source...

Crontab(1) sends messages to cron(1M) via the named pipe /usr/lib/cron/FIFO.
A generic message contains a type, an action, a filename, and a login name.
Messages from crontab(1) pass the user's login name as the crontab file name,
with a type of 'c' for crontab.  An action is either adding or deleting
a crontab file.  I don't think that the login name field is used by the crontab
command.

This pipe is also used by at(1).  Only root processes can read and write the
pipe.
-- 
Steve Alexander, TCP/IP Development | stevea%laidbak@sun.com
Lachman Associates, Inc.            | ...!sun!laidbak!stevea