On Thu, Dec 1, 2016 at 3:33 AM, Pierre Labastie <pierre.labas...@neuf.fr>
wrote:

> On 01/12/2016 07:56, Douglas R. Reno wrote:
>
>> Pierre Labastie wrote:
>>
>>> On 01/12/2016 04:38, Douglas R. Reno wrote:
>>>
>>>> Hello,
>>>>
>>>> Upon trying to run the newaliases command in the Configuration
>>>> Information page, I'll get the following error:
>>>>
>>>> newaliases: cannot open /etc/mail/aliases: Group writable file
>>>>
>>>> For context, these are the commands that I ran (similar to the book):
>>>>
>>>> renodr [ /sources ]$ su
>>>> Password:
>>>> root [ /sources ]# echo $(hostname) > /etc/mail/local-host-names
>>>> root [ /sources ]# cat > /etc/mail/aliases << "EOF"
>>>> > postmaster: root
>>>> > MAILER-DAEMON: root
>>>> >
>>>> > EOF
>>>> root [ /sources ]# newaliases
>>>> newaliases: cannot open /etc/mail/aliases: Group writable file
>>>> root [ /sources ]#
>>>>
>>>> In order to fix this, I had to run something similar to:
>>>>
>>>> root [ /sources ]# chmod -v 644 /etc/mail/aliases
>>>> mode of '/etc/mail/aliases' changed from 0664 (rw-rw-r--) to 0644
>>>> (rw-r--r--)
>>>> root [ /sources ]# newaliases
>>>> /etc/mail/aliases: 2 aliases, longest 4 bytes, 31 bytes total
>>>>
>>>> I propose adding the "chmod -v 644 /etc/mail/aliases" command to the
>>>> book.
>>>>
>>>> I'd like to ask for comments / suggestions before I put it in there
>>>> myself.
>>>>
>>>> I guess it is an "umask" problem. Normally, if your bash startup files
>>> are set as in the book, umask should be 022 when you are root, and no
>>> additional instruction should be necessary. OTOH, maybe su does not run the
>>> bash startup files...
>>>
>>> Regards
>>> Pierre
>>>
>> As far as I can see after tracing it for a little bit, I can't find a
>> line in /root/.bashrc, /etc/profile, /etc/bashrc, or /root/.bash_profile
>> that accomplishes that. However, we do execute it in
>> /etc/profile.d/umask.sh.
>>
>>
>> When I am "su"ed to root, my umask is 0022. If I use my normal user, my
>> umask is 0002.
>>
>> root [ ~ ]# umask
>> 0022
>>
>> renodr [ /sources ]$ umask
>> 0002
>>
>> I just verified that all of my bash startup files are identical to the
>> ones in the book.
>>
>> If I use "su", my umask as root is the same as that of pierre (0002)
> If I use "su -", umask is correctly set to 0022 (but of course the working
> directory is  changed to /root)
> what I use in my scripts is
> sudo -E sh << ROOT_EOF
> <root commands>
> ROOT_EOF
> If I do that, umask is 0022, and CWD is not changed. I cannot understand
> what makes the difference with su (I do not use this command, that's why...)
>
> Pierre
>
>
Hmm...

I can try what you are doing for sudo. In my case, just running "sudo
cat... << EOF" gives me a permission denied error (if I recall correctly, I
haven't tried that in a long time).

Here's an explanation as to why "su - " and "su" do different things.

"su - <user>" forces a new login session to be spawned I think, which is
why it resets the working directory to the new user's home directory. If
one just uses "su" or "su <user>", I think that it tells it to change to
that user but preserve the current environment.
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