RHCE033 Lecture14 $

Data stored on the hard disk is stored numberically

 

ex: 

 

ueradd test01

 

ll-d /home/test01/

 

userdel test01

 

UID or GID are 2023   ,for  The user is deleted

 

tail /etc/shadow

 

useradd

 

useradd -s /sbin/nologin 

 

uesermod -a -G users david

 

add user to a group

 

uid

gid        user's private group

Gid       add group

 

tom: gid  

 

ll /var/log/messages

 

ps -ef |grep log

 

id mail

 

last  

 

lastb    serch who login in my computer

 

umask :

 

                        666       777 

root :022         644       755

 

        002          664       775

 

        033          644       744

 

                     rw-rw-rw-

033              ---wx-wx   

                     rw-r--r-- 

                         644

 

 

suid  command run with permissions of the owner of the command .not executor of the command

 

sgid  command runs with group affiliation of the group of the command

 

find / -perm -2000

------------------------------------

mkdir /data

 

chmod 777 /data

 

chmod g+s  /data

 

chgrp users /data/

 

usermod -a -G users user1

 

usermod -a -G users david

 

4   suid 2 sgid  1stiky

chmod 3777

 

find / -perm -4000     find the suid firm