~~~~~~~~~~~~~~~~~~~~~~~~~~PERMISSIONS~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Permissions:-
permissions on a user are of two types_______________________________
Permissions owner group
permission umask
1_Directory
permissions. | drwxr-xr-x root root
755 0022
2_File
permissions. | -rw-r--r-- root root 644 0022
A
FILE HAVE NOT THE EXECUTE PERMISSIONS BECOUSE WRITE
Read – {4} PERMISSION
FOR FILE ACTS AS A EXECUTES PERMISSION.
Write –{2} + =
7 which is the full permission for the
file or the directory.
Execute{1}
1_ r:- read permission. {4} |for
directory drwxr-xr-x
2_ w:- write permission. {2} |
3_ x:-
execute permission.{1} | this {d} shows that this permission is
for directory
4_
-:_ no permission. {-} |for
file -rw-r--r-- this is the permission for file.
Now permission of a file is
applied on the {user}, {group}
and {other user} they have all different
permissions to understand below _________________........
Take a directory it has 9 digit permission
like :--------
Directory for Users for Groups for Other users defaults permis..
Redhat d rwx r-x r-x per.. 7 5 5
421 421 421 for U G O umask0 2 2 this
{d} shows {7} full permission {5} read, execute for {5} read , execute for the other this is a directory for the users/ owner all groups users
which are not member of
any group.
File for Users for
Groups for Other
users default permission
server {-} rw-
r-- r-- per .. 6
4 4
421 421 421 for
G U O
Umask 0 2 2
At first
position {-} read, write per.. only read for all groups only read for all other users
Shows that it’s a file for users/owner {{{{ }}}}}}}}}}}}}}}}}}}
EXPLAIN SOME OF HOW THE PERMISSIONS APPLIED
____________________________
ROOT USER OR GROUP USER
OR ALL OTHER USERS WHO NOT BELONG THE
OWNER OF THE FILE MEMBERS OF THE FROUP TO ANY GROUP.
|
These are the simple
permissions for a file or directory by a user for groups and other user
Now how to apply permissions
Go to the directory in which directory or file to
which permissions are applied then run the commands
Like we have to apply permission on /data file
# cd /
/]# chmod
777{ or any of permission u wants} file or dir.. name like
/]# chmod
744 /data
Or
/]# chmod
644 myfile
OWNERSHIP to give ownership of a file or directory to
any other user BY ROOT ONLY
# chown pop
[filename]
Username
The user who makes he file he has the full rights on his
file he can do any thing with his file.
And if root write {0} in
the permissions at any permissions place. Then user belogs to thet permission
even can`t open his own file because {0} refers to no permission
This security of {0} also
acts on the groups level security if __0777 then users under group can do
nothing.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
The default roots id is {0}
Every user has its own
primary/private group when we add this into a group then this group is its
secondary group. And then this user is member of both of the groups
primary and secondary.
After add it to secondary group then the group
level security is applied on this that
is as _____
THSES PERMISSIONS IMPLIMENTS ONLY ON THE GROUPS AND
USERS UNDER GROUPS.
1_ SUID____ Set User
Identification. {4}
2_ SGID___ Set Group identification {2}
3_STICKBIT _for restriction to
delete {1}
These permissions acts only
on the groups and the users under the group its add as a first digit for the
permissions like
To give a user under a group
to read permission only on the other members of this group
File is pop
# chmod 4777 pop
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