[root@a ~]# mkdir -pv g1 g2
mkdir: created directory 'g1'
mkdir: created directory 'g2'
[root@a ~]# ll
total 8
-rw-------. 1 root root 1563 Nov 16 20:15 anaconda-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Desktop
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Documents
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Downloads
drwxr-xr-x. 2 root root 6 Nov 24 18:42 g1
drwxr-xr-x. 2 root root 6 Nov 24 18:42 g2
-rw-r--r--. 1 root root 1718 Nov 16 22:07 initial-setup-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Music
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Pictures
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Public
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Templates
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Videos
[root@a ~]# useradd owner1
[root@a ~]# useradd owner2
[root@a ~]# useradd owner3
[root@a ~]# useradd owner4
[root@a ~]# groupadd group1
[root@a ~]# groupadd group2
[root@a ~]# usermod -g group1 owner1
[root@a ~]# usermod -g group1 owner2
[root@a ~]# usermod -g group2 owner3
[root@a ~]# usermod -g group2 owner4
[root@a ~]# ll g1
total 0
[root@a ~]# ls g1
[root@a ~]# chgrp group1 g1
[root@a ~]# chmod 750 g1
[root@a ~]# chgrp group2 g2
[root@a ~]# chmod 750 g2
[root@a ~]# mkdir sc
[root@a ~]# groupadd shengchan
[root@a ~]# chmod 770 sc
[root@a ~]# chmod g+s sc
[root@a ~]# chown .shengchan sc
[root@a ~]# ll
total 8
-rw-------. 1 root root 1563 Nov 16 20:15 anaconda-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Desktop
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Documents
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Downloads
-rw-r--r--. 1 root root 1718 Nov 16 22:07 initial-setup-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Music
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Pictures
drwxrwxrwt. 2 root root 6 Nov 24 19:08 pub
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Public
drwxrws---. 2 root shengchan 6 Nov 24 19:17 sc
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Templates
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Videos
[root@a ~]# mkdir cw
[root@a ~]# groupadd caiwu
[root@a ~]# chmod 770 cw
[root@a ~]# chmod g+s cw
[root@a ~]# chown .caiwu sc
[root@a ~]# ll
total 8
-rw-------. 1 root root 1563 Nov 16 20:15 anaconda-ks.cfg
drwxrws---. 2 root root 6 Nov 24 19:26 cw
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Desktop
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Documents
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Downloads
-rw-r--r--. 1 root root 1718 Nov 16 22:07 initial-setup-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Music
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Pictures
drwxrwxrwt. 2 root root 6 Nov 24 19:08 pub
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Public
drwxrws---. 2 root caiwu 6 Nov 24 19:17 sc
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Templates
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Videos
[root@a ~]# which touch
/usr/bin/touch
[root@a ~]# useradd admin
[root@a ~]# chmod u+s /usr/bin/touch
[root@a ~]# ll
total 8
-rw-------. 1 root root 1563 Nov 16 20:15 anaconda-ks.cfg
drwxrws---. 2 root root 6 Nov 24 19:26 cw
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Desktop
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Documents
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Downloads
-rw-r--r--. 1 root root 1718 Nov 16 22:07 initial-setup-ks.cfg
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Music
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Pictures
drwxrwxrwt. 2 root root 6 Nov 24 19:08 pub
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Public
drwxrws---. 2 root caiwu 6 Nov 24 19:17 sc
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Templates
drwxr-xr-x. 2 root root 6 Nov 16 22:30 Videos