umask in scripts.

[brian_31]

Hi:

How do you handle umask in scripts? Any tips welcome.

Thanks
Brian.

[Sridhar Bhaskarla]

Brian,

Can you be more specific?.

I don't pay much attention to umask as the script will run in a new shell. If I need the umask from the script to the current shell, then I will dot (.) in the script.

-Sri

[Michael Tully]

umask can be handled just like any other environment variable.

e.g.

umask 022

If I wanted to change the default mask of root for example I will change the umask in the script. If I don't I leave it alone and it will pick up the default of the user running it.

[John Poff]

Hi,

Do you mean, how do you set it in a script? Just do a 'umask 027' and that should set it for the duration of your script.

JP

[James R. Ferguson · Accepted solution]

Hi Brian:

As required, set it the way you want in your script:

# umask 027

For directories, you could do something like:

# mkdir -m 750 /tmp/mydir

Note in the above that a 'mkdir' yields the same permissions with either form when 'umask' as set as shown.

Regards!

...JRF...

[A. Clay Stephenson]

I handle it something like this:

SAVEMASK=$(umask 007)
echo "This is a test" > myfile
# restore to original value for following commands
umask ${SAVEMASK} > /dev/null

[Benedict Adamson]

If a script must create files with specific permissions, do not rely on the inherited umask value being acceptable. In particular, take care with scripts that you intend the root user to run. I've seen root umasks of 0, leaving files and directories wide open.