On Thursday 08 February 2007 09:29, edwardspl(a)ita.org.mo
wrote:
Les Mikesell wrote:
>edwardspl(a)ita.org.mo wrote:
>>>>chmod g+rwx ( What number of g+rwx, eg : ?77 )
>>>> /home/edward
>>>
>>>You can use the symbolic form literally. I think it's
>>> easier to understand. Let the computer do the
>>> binary/octal math. g+rwx means add the read, write,
>>> and execute bits for the group.
>>
>>But I want to know what no of g+rwx...
>
>The + means it is added to the bits already permitted.
> Look at them as groups of 3 bits in binary and take the
> octal value.
>
> user group other
> rwx rwx rwx
>
>You'll start with a home dir having rwx --- --- so
> that's 111 000 000 binary or 700 octal.
>Add the group rwx and you get 111 111 000 or 770 octal
So, g+rwx = 770, right ?
>>>>chmod +t ( What number of +t ) /home/edward
>
>That's one more bit to the left, 1 000 000 000 binary,
> so 1000 octal. Add that to what you have.
>
>>>Same here, you can type it that way and it means add
>>> the "sticky" bit.
>>
>>Also want to know...
>
>Altogether, the octal value for the mode ends up at
> 1770. But, as I said before the computer does a better
> job of thinking in octal.
So, +t = 1770, right ?
Edward.
When I first started learning how to write the permissions
setting RWX I could not figure out how to do it using the
letters. I found it very easy to understand doing it with
the numbers. I type it like this chmod 777 <file> to get
the rwxrwxrwx and if I want to change it to rwxr-xr-x I
just type chmod 755 <file> and if I want rwx------ I type
chmod 700 <file>. I am sure I can figure out how to write
it with the letters now but I think it is much easier to
use the numbers.