Security 1

[071]

Hi !
Does anyone know the numerical value of security permissions, rwx etc...
Also how can the format -rwxr-xr-x be interperated ?
Not sure which is group, owner.

Cheers,
71

 

[grega]

017,

Permissions are grouped in 3 parts, each with 3 settings. The first "dash" on the permissions list deals with the type of file (directory, block-special, link, etc.) .. don't worry about that.

The rest of the permissions, in groups of 3, refer to the owner, group, world in that order. So permissions of

-rwxrw-r--

mean

rwx ... the owner has full permissions on the file

rw- ... the group has read/write permissions

r-- ... all other users have read permission

Each group of three permissions can also be specified in Octal notation ...
[tt]
4 2 1 4 2 1 4 2 1
- r w x r w - r - -
[/tt]
So the octal notation for this would be 764, i.e. owner has full permission (4+2+1), group has read/write permission (4+2), others only have read permission (4)

You can use this notation in the chmod command, so if you wanted to change a file to the above permissions, all you need to do is

chmod 764 filename

Hope this helps a bit!

Greg.

 

[071]

Thanks Greg

 

[071]

What about umask and ACL permissions ?
Please help ! I've got the sysadmin exam tomorrow !

 

[grega]

Doing a <b>man umask</b> should tell you all you need to know. As for ACL, don't think I've even heard of them!

Greg.