suid:以属主的身份去执行命令 任何命令、程序在执行期间都具有身份 [user2@room9pc01 ~]$ ls /root #失败 [root@room9pc01 ~]# chmod u+s /usr/bin/ls

[user2@room9pc01 ~]$ touch u1.txt #touch命令未加suid权限时创建文件 [root@room9pc01 ~]# chmod u+s /usr/bin/touch [user2@room9pc01 ~]$ touch u2.txt #touch 命令加suid权限后创建文件 [user2@room9pc01 ~]$ ll 总用量 0 #文件所有者所属组都是命令执行者的 -rw-rw-r--. 1 user1 user1 0 4月 2 20:41 u1.txt -rw-rw-r--. 1 root user1 0 4月 2 20:41 u2.txt sgid:创建文件继承父目录属组 [root@room9pc01 ~]# mkdir /tmp/demo [root@room9pc01 ~]# chown .user1 /tmp/demo/ [root@room9pc01 ~]# ll -d /tmp/demo/ drwxr-xr-x. 2 root user1 4096 4月 2 21:00 /tmp/demo/ [root@room9pc01 ~]# cp /etc/passwd /tmp/demo/ [root@room9pc01 ~]# ll -d /tmp/demo/ drwxr-xr-x. 2 root user1 4096 4月 2 21:01 /tmp/demo/ [root@room9pc01 ~]# ll -d /tmp/demo/passwd -rw-r--r--. 1 root root 2825 4月 2 21:01 /tmp/demo/passwd [root@room9pc01 ~]# chmod g+s /tmp/demo [root@room9pc01 ~]# cp /etc/host host.conf hostname hosts hosts.allow hosts.deny
[root@room9pc01 ~]# cp /etc/hosts /tmp/demo/ [root@room9pc01 ~]# ll -d /tmp/demo/hosts -rw-r--r--. 1 root user1 503 4月 2 21:02 /tmp/demo/hosts

sticky bit:只允许修改自己的文件 [root@room9pc01 ~]# mkdir /tmp/share [root@room9pc01 ~]# ll -ld /tmp/share drwxr-xr-x. 2 root root 4096 4月 2 21:07 /tmp/share [root@room9pc01 ~]# chmod 777 /tmp/share [root@room9pc01 ~]# chmod o+t /tmp/share [root@room9pc01 ~]# ll -ld /tmp/share drwxrwxrwt. 2 root root 4096 4月 2 21:07 /tmp/share [user2@room9pc01 share]$ echo 'how are you?' > /tmp/share/user2.txt [user1@room9pc01 ~]$ echo 'who are you?' > /tmp/share/user1.txt [user1@room9pc01 ~]$ rm -rf /tmp/share/user2.txt rm: 无法删除"/tmp/share/user2.txt": 不允许的操作