Re: [gentoo-user] executing a command as a nologin user

[wabe]

Fernando Rodriguez <cyklonite@×××××.com> wrote:

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> On 07/13/2016 07:10 AM, Alan McKinnon wrote:
> > On 12/07/2016 03:47, jens w wrote:
> >> .procmailrc
> >> :0 c
> >> * !^X-Loop: name@×××××××.com
> >> | formail -X "From:" | $HOME/bin/script.sh
> >>
> >> procmail.log
> >> procmail: Executing " formail -X "From:" | $HOME/bin/script.sh
> >>
> >> for incoming mail, a script is executed. logfile has the same
> >> entry as it is in other users. but the script do nothing.
> >>
> >> How executing a command as a nologin user?
> >>
> >
> >
> > You can't, not the way you are doing it.
> > You want to launch a shell script for the user, but the user's
> > shell is /sbin/nologin. This exits immediately without launching
> > the script.
> >
> > Give the user a real shell.
> >
> > Alan
> >
>
> I've been following this thread and thinking the same thing but
> wasn't sure.

I don't think so. To proof it, I created this user:

nologinuser:x:1015:1016::/home/nologinuser:/sbin/nologin

Then I created this script:

#!/bin/sh
#
date >> /home/nologinuser/envars.txt
echo $HOME >> /home/nologinuser/envars.txt
echo $PATH >> /home/nologinuser/envars.txt
echo "-----------------------" >> /home/nologinuser/envars.txt

I stored it as /var/script-nologinuser/testscript.sh. I had to store 
it at this place because /home is mounted with the noexec option on 
my system.


Then I created a cronjob for the nologinuser user:

*/2 * * * * /var/script-nologinuser/testscript.sh


The result is the file /home/nologinuser/envars.txt with this
content:

Wed Jul 13 18:10:01 CEST 2016
/home/nologinuser
/usr/bin:/bin
-----------------------
Wed Jul 13 18:12:01 CEST 2016
/home/nologinuser
/usr/bin:/bin
-----------------------


The ownership and the rights for /home/nologinuser/, 
/var/script-nologinuser/ and /var/script-nologinuser/testscript.sh
are nologinuser:nologinuser and 700.

So it seems, that it is possible to execute scripts without setting
a shell in /etc/passwd.

I don't know why it doesn't work for jens w.

--
Regards
wabe