umask

[Stéphane Gauthier]

Hello, here is my question. First what is the real default umask value or permission on HP-UX. Is it 022? How come all books says to set default permission use command umask 000? Can you explain?

[James R. Ferguson]

Hi Stephane:

You should establish an appropriate default umask for every user in the user's profile.

For root, this should be at least 022 or even 027. For all other users, 022 is very appropriate.

Setting the umask to 000 would simply mean that directories are created with octal permissions 777 (read, write, execute for the owner, group and world); and files with octal 666 (read, write).

This is far too insecure.

Regards!

...JRF...

[A. Clay Stephenson]

There is no default umask setting and thus it becomes 0000. Generally one of the first things you do is edit /etc/skel/.profile and add a umask value there so that when new users are created they get a defined umask value.

You books are telling you to set umask to 000 so that when software in installed/copied that the original modes of the files are retained. There are two components in play when a file is created: 1) the mode 2) umask. Umask "subtracts" from mode. (it really isn't subtraction but you can think of it that way). By setting umask to 000, no "subtraction" occurs and the files are installed with their mode intact. This may not be a good thing because running with umask 0000 is normally a security risk.

[Stéphane Gauthier]

Tks for your replay. But I am asking these questions because they are part of the study book for the HP-UX system CSA exam and I don,t really get it. Here are the question on the book.

What is the default umask value in HP-UX?
A. 002
B. 022
C. 222
D. 200


What command will you use to ensure that the default permissions are being used?

A. setperm 777
B. setperm
C. setperm umask
D. umask 000

So I would say B to the fisrt question and D to second question, but still don't get it.

[Peter Nikitka]

Hi,

I think the is a default setting in
/etc/profile
which is used for all users with Bourne-shellstyle and in
/etc/*csh* OR /etc/.login
for those with Cshell style.

mfG Peter

[A. Clay Stephenson]

This illustrates what I consider to be wrong with the entire certification process.

What is the default umask value in HP-UX?
A. 002
B. 022
C. 222
D. 200

The "real" answer is none of the above because an untrusted system has a default umask of 0 and a trusted system has a umask of 077. The question is also a bit nebulous in that the specific version of HP-UX is not mentioned so that really old versions might be different.


What command will you use to ensure that the default permissions are being used?

A. setperm 777
B. setperm
C. setperm umask
D. umask 000

In this case D is correct because with a umask of 000 the permissions (more properly "mode") will be left intact.

[Ivan Ferreira]

For the first is 022, this is the default, for the second, I think that there is something wrong with the question. No answer is right. The answer should be umask 022.

Sometimes, these errors happens on study guides.

[Bharat Katkar]

What is the default umask value in HP-UX?
A. 002
B. 022
C. 222
D. 200
Ans: B

What command will you use to ensure that the default permissions are being used?

A. setperm 777
B. setperm
C. setperm umask
D. umask 000

Ans: D

These are the expected answers.

Regards,

[Jeff_Traigle]

As Ivan points out, you really must be careful relying on the questions and answers in Raqeef's study guide. I found numerous errors in the first edition I used to study for the CSA exam back in 2001. I haven't read the second edition so don't know if much improvement was made.

Use the study guide as just that... a guide. If there's anything that isn't clear, looks contradictory, or you just want verification of its validity, always use the primary sources of information... man pages and other documentation that you can find on http://docs.hp.com/.

[Richard Darling]

I always check for any errata that may have been found since the publishing of a technical book. For Rafeeq's book it is:

http://www.hp.com/hpbooks/prentice/ptr_0130183741.html

You will see the 'publishers errata' on the right-hand side. I sent Rafeeq a list of seven errors from the first publishing in 2000, and he was extremely appreciative.

[Tor-Arne Nostdal]

I've also tried out similare exams, and found same type of ambigous questions.

Clay's answer is perfect, and if you posess the same kind of knowledge you could easily be confused by such questions.

Bharats answer is also great.
"These are the EXPECTED answers"

The point would often be to get a high score on the test. It might not be easy to convince those holding the exam, that there's something wrong in the test...

So the correct here woul be:
- Get the knowledge shown by Clay
- Use your intelligence as shown by Bharat

If you handle both you will become an excellent system administrator!

/Tor-Arne