Linux 命令笔记（1）

[root@Oracle11_2 ~]# ll
total
-rw-------.  root root    May   : anaconda-ks.cfg
drwxr-xr-x.  root root    May  : backup
drwxr-xr-x   root root    May  : Desktop
drwxr-xr-x   root root    May  : Documents
drwxr-xr-x   root root    May  : Downloads
-rw-r--r--.  root root    May   : install.log
-rw-r--r--.  root root    May   : install.log.syslog
drwxr-xr-x   root root    May  : Music
-rw-r--r--   root root  Aug    pdksh-5.2.-.el5_8..x86_64.rpm
drwxr-xr-x   root root    May  : Pictures
drwxr-xr-x   root root    May  : Public
drwxr-xr-x.  root root    May   : scripts
drwxr-xr-x   root root    May  : Templates
drwxr-xr-x   root root    May  : Videos

用户读取目录的权限应该是5(r-x) 而不是 4(r--) ,x意味着有在目录下执行命令的权限。

[root@Oracle11_2 ~]# useradd backup
[root@Oracle11_2 ~]# useradd jingy
[root@Oracle11_2 ~]# su - backup
[backup@Oracle11_2 ~]$ id
uid=(backup) gid=(backup) groups=(backup)
[backup@Oracle11_2 ~]$ exit
logout
[root@Oracle11_2 ~]# su - jingy
[jiongy@Oracle11_2 ~]$ id
uid=(jingy) gid=(jingy) groups=(jingy)
[jiongy@Oracle11_2 ~]$ exit
logout
[root@Oracle11_2 ~]# usermod -a -G backup jingy
[root@Oracle11_2 ~]# su - jingy
[jiongy@Oracle11_2 ~]$ id
uid=(jiongy) gid=(jingy) groups=(jingy),(backup)
[jiongy@Oracle11_2 ~]$ id
uid=(jiongy) gid=(jingy) groups=(jingy),(backup)

usermod -G backup jingy #修改用户次要组信息
usermod -a -G backup jingy #将用户添加到新的次要组中