topic Re: cannot edit crontab within script sessions in Operating System - HP-UX

cannot edit crontab within script sessions

Ben Dehner — Fri, 04 Aug 2006 10:14:47 GMT

This one's got me baffled. I've got crontab set up for some normal users. If you invoke 'crontab -e', you can modify and save the crontab file as normal. However, if you are within a 'script' session, that is

script somefile
crontab -e

crontab still invokes the editor (vi) as normal, but when you try to exit, it gives an error message

crontab: can't create your crontab file in the cdrontab directory.

Funny thing, I have no problems on our 11.23 system, but I see this problem on our 11.11 systems. And yes, I know capturing the output of a vi editor in a script is of dubious value, but that's another matter.

Re: cannot edit crontab within script sessions

Peter Godron — Fri, 04 Aug 2006 10:36:50 GMT

Ben,
when you run crontab -e it uses a temporary file to edit in vi. On exit it writes the data back to the original file.

Have you compared privs on /usr/bin/crontab ?

Re: cannot edit crontab within script sessions

Ben Dehner — Fri, 04 Aug 2006 10:54:27 GMT

Priviledges on /usr/bin/crontab was one of the first things I checked; looks fine. (Perm 4555, owner/group = root/bin). I also checked the permission on the /var/spool/cron/crontabs directory, and those all look good.

Re: cannot edit crontab within script sessions

Peter Nikitka — Fri, 04 Aug 2006 11:02:31 GMT

Hi,

I definitly would not call "crontab -e" in a script.
Let another file be processed by your script, initialized via
crontab -l >tmpfile

After all modifications are done, perform something like

if crontab tmpfile
then rm tmpfile
else
# do error processing, tmpfile kept
fi

mfG Peter

Re: cannot edit crontab within script sessions

Jonathan Fife — Fri, 04 Aug 2006 11:05:00 GMT

/usr/bin/script doesn't have setuid, does it?

If you start script can you do a 'crontab -l > my.cron', then 'crontab my.cron', or do you get the error then, too?

If not, you could script a
crontab -l > my.cron && vi my.cron && crontab my.cron
command.

Re: cannot edit crontab within script sessions

Ben Dehner — Fri, 04 Aug 2006 12:51:56 GMT

Weird.

If I do

crontab -l > tmpfile
... edit tmpfile
crontab tmpfile

it works and I don't get the error.

Re: cannot edit crontab within script sessions

A. Clay Stephenson — Fri, 04 Aug 2006 12:54:04 GMT

In any event, the 3 step process is, by far, the better approach. crontab -e is an accident waiting to happen and I never use it.

Re: cannot edit crontab within script sessions

Ben Dehner — Fri, 04 Aug 2006 13:44:24 GMT

I'm still confused, but I guess I have a suitable workaround. Thanks.

Re: cannot edit crontab within script sessions

Ben Dehner — Fri, 04 Aug 2006 13:45:17 GMT

Using crontab -l > file will work for me.