Linux命令：文件和目录权限管理-优快云博客

文件和目录权限管理（1）

$》:在Linux系统中，每个文件和目录都有访问的许可权限，用它来确定用户能以何种方式对文件和目录进行访问和操作。

$》：文件或目录的访问权限分为只读，只写和可执行三种。以文件为例，只读权限表示只允许读其内容，而不能对其内容进行任何的修改操作；可执行权限表示允许将该文件作为一个程序执行。

如图：

root@ubuntu:~# cd /home/weijunqiang/Documents

root@ubuntu:/home/weijunqiang/Documents# ll

total 36

drwxr-xr-x 9 weijunqiang weijunqiang 4096 Feb 7 07:48 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

root@ubuntu:~# ll

total 10588

drwx------ 4 root root 4096 Feb 7 03:28 ./

drwxr-xr-x 24 root root 4096 Feb 7 07:00 ../

-rw-r--r-- 1 root root 74 Feb 6 23:02 argv.awk

-rw------- 1 root root 112 Feb 6 13:01 .bash_history

-rw-r--r-- 1 root root 3106 Apr 19 2012 .bashrc

-rw-r--r-- 1 root root 10796012 Feb 6 12:44 Bryan_Adams-Here_I_Am.mp3

drwx------ 2 root root 4096 Feb 6 22:42 .cache/

-rw-r--r-- 1 root root 3633 Jan 28 08:12 english-2015-1-28.txt

-rw-r--r-- 1 root root 140 Apr 19 2012 .profile

drwx------ 2 root root 4096 Feb 6 22:29 .pulse/

-rw------- 1 root root 256 Feb 6 19:19 .pulse-cookie

-rw------- 1 root root 2652 Feb 7 03:28 .viminfo

权限三位(rwx:读、写、可执行)为一组，开头(权限位的第一位)为d表示目录，开头(权限位的第一位)为-表示文件

drwxr-xr-x 24 root root 4096 Feb 7 07:00 ../

rwx(rwx：可读可写可执行):属主用户权限位

r-x(r-x：可读不可写可执行)：与文件属主同组的用户权限位

r-x(rwx：可读不可写可执行)：其它用户权限位

-rw-r--r-- 1 root root 74 Feb 6 23:02 argv.awk

rw-(rwx：可读可写不可执行): 属主用户权限位

r--(rwx：可读不可写不可执行)：与文件属主同组的用户权限位

r-(rwx：可读不可写不可执行)-：其它用户权限位

文件和目录权限管理（2）

》文件和目录权限管理依赖于两个极其重要的命令：更改文件(目录)权限命令chmod和更改文件(目录)用户命令chown

》chmod命令格式：

chmod [userType] [signal] [type] [filename]

用户类型	数学符号	文件类型
u表示用户(user),即文件和目录的所有者	+ 添加某个权限	r可读
g表示同组(group)，即与文件属主同组的用户	- 取消某个权限	w可写
o表示其他(other)用户	= 赋予给定权限并取消其他所有权限	x可执行
a表示所有(all)用户。它是系统默认值

root@ubuntu:/home/weijunqiang/Documents# ls

java-ws mv_cp_temp mydirs mydirs001 notes rm01 workspace

root@ubuntu:/home/weijunqiang/Documents# vi test.html

<!doctype html>

<html>

<head>

<head>

<body>

<b>Hello World!</b>

</body>

"test.html" [New] 8L, 92C written

root@ubuntu:/home/weijunqiang/Documents# ls

java-ws mv_cp_temp mydirs mydirs001 notes rm01 test.html workspace

root@ubuntu:/home/weijunqiang/Documents# ll

total 40

drwxr-xr-x 9 weijunqiang weijunqiang 4096 Feb 7 08:50 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rw-r--r-- 1 root root 92 Feb 7 08:50 test.html

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

root@ubuntu:/home/weijunqiang/Documents# ll test.html

-rw-r--r-- 1 root root 92 Feb 7 08:50 test.html

# u+x,g+x:用户主，同组用户都添加可执行的权限

root@ubuntu:/home/weijunqiang/Documents# chmod u+x,g+x test.html

root@ubuntu:/home/weijunqiang/Documents# ll test.html

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

root@ubuntu:/home/weijunqiang/Documents# mkdir promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwxr-xr-x 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

root@ubuntu:/home/weijunqiang/Documents# ll promiss_dir

total 8

drwxr-xr-x 2 root root 4096 Feb 7 08:54 ./

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ../

root@ubuntu:/home/weijunqiang/Documents# ll promiss_dir/

total 8

drwxr-xr-x 2 root root 4096 Feb 7 08:54 ./

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ../

root@ubuntu:/home/weijunqiang/Documents# chmod o-x,a+r promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwxr-xr-- 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

root@ubuntu:/home/weijunqiang/Documents# chmod u-r,u-x promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

d-w-r-xr-- 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

# u+x,u+r,g-x,g-r,o-r 用户主添加可执行可读权限，同组用户取消可执行可读权限，其他用户取消可读权限

root@ubuntu:/home/weijunqiang/Documents# chmod u+x,u+r,g-x,g-r,o-r promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwx------ 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

# a+x,a+r,a+w用户主、同组用户、其他用户均添加可执行可读可写的权限

root@ubuntu:/home/weijunqiang/Documents# chmod a+x,a+r,a+w promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwxrwxrwx 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

文件和目录权限管理（3）

》权限的数字表示方法

》0表示没有权限， 1表示可执行权限，2表示可写权限，4表示可读权限

》将上面的数字相加，形成3个从0到7的八进制数，其顺序是u(用户主user), g(同组用户group), o(其他用户other)

》chmod u+x,g+w test.txt等价于(假设test.txt文件的权限是 rw-r--r-- )

》chmod 764 test.txt 即表示test.txt 文件，用户主权限为可读可写可执行(4+2+1=7)，同组用户可读可写不可执行(4+2=6)，其他用户可读不可写不可执行(4)。

root@ubuntu:/home/weijunqiang/Documents# clear

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

#当前所有用户都具有可读可写可执行权限

drwxrwxrwx 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

#将文件夹权限改为用户主拥有可读可写可执行权限(4+2+1=7),群组用户、其他用户权限改为可读不可写不可执行(4)

root@ubuntu:/home/weijunqiang/Documents# chmod 744 promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

drwxr--r-- 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

文件和目录权限管理（4）

》chown命令可以该变变文件或目录的属主。一般来说，这个指令只有是由系统管理者(root)所使用的，一般使用者没有权限改变别人的文件或目录属主。

》chown [option] [owner] [filename]

》 -R是最常用的选项，对目前目录下的所有文件与子目录进行相同的拥有者变更。

root@ubuntu:/home/weijunqiang/Documents# clear

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

#文件夹promiss_dir所属主为root

drwxr--r-- 2 root root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

#文件夹promiss_dir所属主改为weijunqiang

root@ubuntu:/home/weijunqiang/Documents# chown weijunqiang promiss_dir

root@ubuntu:/home/weijunqiang/Documents# ll

total 44

drwxr-xr-x 10 weijunqiang weijunqiang 4096 Feb 7 08:54 ./

drwxr-xr-x 24 weijunqiang weijunqiang 4096 Feb 7 03:09 ../

drwxrwxr-x 3 weijunqiang weijunqiang 4096 Feb 7 02:40 java-ws/

drwxr-xr-x 4 root root 4096 Feb 7 07:14 mv_cp_temp/

drwxr-xr-x 3 root root 4096 Feb 7 07:45 mydirs/

drwxrwxrwx 2 root root 4096 Feb 7 07:48 mydirs001/

drwxrwxr-x 2 weijunqiang weijunqiang 4096 Feb 7 03:47 notes/

#文件夹promiss_dir所属主已被改为weijunqiang

drwxr--r-- 2 weijunqiang root 4096 Feb 7 08:54 promiss_dir/

drwxr-xr-x 3 root root 4096 Feb 7 07:30 rm01/

-rwxr-xr-- 1 root root 92 Feb 7 08:50 test.html*

drwxr-xr-x 7 root root 4096 Feb 7 07:05 workspace/

转载于:https://www.cnblogs.com/weijunqiang/articles/4279611.html