Re: [vox-tech] how does umask work?

[Harry Souders <gnulinux@MAPSrosecomputing.com>]

On Tue, Mar 27, 2001 at 11:10:28AM -0800, Peter Jay Salzman wrote:
> i think you're thinking of chmod, not umask.
> 
> ok, so how do i set a umask of --x--x--x ?

I give up, how?
Actually, my question is "why doesn't umask work like I thought it
would?"

Since we are just 'masking' bits, it would seem that a umask of 666
would create files with attributes of 111 (ie. --x--x--x ). What it
file attributes you actually get are 000 (ie. --------- ).

So, I set my umask to 666:
        umask 666

Next I type umask -S to confirm this:

        umask -S

The result is:
u=x,g=x,o=x

Looks okay, eh?

Now, I create a file and see what the file attributes are:

        date > testfile

Checking testfile:
        ls -la testfile

And, I get:
        ----------    1 hsouders hsouders

Yikes! Not exactly what I was expecting.

It appears that umask is ANDing 0666 against whatever the umask value
is. 

Why? I'm not sure.
Maybe it inherited a file mode of 0666, or maybe it has to do with
'mount' options, or maybe the 0666 is hard-coded someplace.
Anyone know?