2- 设置文件的权限及归属

2016.6.9

设置文件的权限chmod

• 格式1

  • chomd [ugoa] [+-=] [rwx] 文件...

• 格式2

  • chmod nnn 文件...

[root@test1 dev]# chmod --help
Usage: chmod [OPTION]... MODE[,MODE]... FILE...
  or:  chmod [OPTION]... OCTAL-MODE FILE...
  or:  chmod [OPTION]... --reference=RFILE FILE...
Change the mode of each FILE to MODE.

  -c, --changes           like verbose but report only when a change is made
      --no-preserve-root  do not treat `/' specially (the default)
      --preserve-root     fail to operate recursively on `/'
  -f, --silent, --quiet   suppress most error messages
  -v, --verbose           output a diagnostic for every file processed
      --reference=RFILE   use RFILE's mode instead of MODE values
  -R, --recursive         change files and directories recursively
      --help     display this help and exit
      --version  output version information and exit

Each MODE is of the form `[ugoa]*([-+=]([rwxXst]*|[ugo]))+'.

Report chmod bugs to [email protected]
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'chmod invocation'
[root@test1 dev]#

octal [oc·tal || 'ɑktl /'ɒktl]
adj. 八进制的, 以八为基础, 以八为基础的 (计算机, 电子学用语)

设置文件的权限chmod

示例1：调整mymkdir文件的权限，为属主用户添加执行权限，删除其他用户的读取权限
示例2：将mymkdir文件的访问权限设置位“rwxr-xr-x”

示例1：

[root@test1 jason]# mkdir learn
[root@test1 jason]# ls
learn
[root@test1 jason]# cd learn
[root@test1 learn]# touch mymkdir
[root@test1 learn]# ls
mymkdir
[root@test1 learn]# ll
total 0
-rw-r--r-- 1 root root 0 Jun  9 10:27 mymkdir
[root@test1 learn]# chmod u+x,o-r mymkdir
[root@test1 learn]# ll
total 0
-rwxr----- 1 root root 0 Jun  9 10:27 mymkdir
[root@test1 learn]#

示例2：

添加要求权限方法一：

[root@test1 learn]# chmod u=rwx,g=rx,o=rx mymkdir
[root@test1 learn]# ll
total 0
-rwxr-xr-x 1 root root 0 Jun  9 10:27 mymkdir
[root@test1 learn]#

去掉所有权限

[root@test1 learn]# chmod 000 mymkdir
[root@test1 learn]# ll
total 0
---------- 1 root root 0 Jun  9 10:27 mymkdir
[root@test1 learn]#

添加要求权限方法二：
```bash
[root@test1 learn]# chmod 755 mymkdir
[root@test1 learn]# ll
total 0
-rwxr-xr-x 1 root root 0 Jun  9 10:27 mymkdir
[root@test1 learn]#

设置文件的归属chown

• 格式
  • chown 属主 文件
  • chown :属组 文件
  • chown 属主:属组 文件

示例：将mymkdir文件的属主更改为daemon、属组更改为wheel

[root@test1 learn]# chown --help
Usage: chown [OPTION]... [OWNER][:[GROUP]] FILE...
  or:  chown [OPTION]... --reference=RFILE FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP.
With --reference, change the owner and group of each FILE to those of RFILE.

  -c, --changes          like verbose but report only when a change is made
      --dereference      affect the referent of each symbolic link (this is
                         the default), rather than the symbolic link itself
  -h, --no-dereference   affect each symbolic link instead of any referenced
                         file (useful only on systems that can change the
                         ownership of a symlink)
      --from=CURRENT_OWNER:CURRENT_GROUP
                         change the owner and/or group of each file only if
                         its current owner and/or group match those specified
                         here.  Either may be omitted, in which case a match
                         is not required for the omitted attribute.
      --no-preserve-root  do not treat `/' specially (the default)
      --preserve-root    fail to operate recursively on `/'
  -f, --silent, --quiet  suppress most error messages
      --reference=RFILE  use RFILE's owner and group rather than
                         specifying OWNER:GROUP values
  -R, --recursive        operate on files and directories recursively
  -v, --verbose          output a diagnostic for every file processed

The following options modify how a hierarchy is traversed when the -R
option is also specified.  If more than one is specified, only the final
one takes effect.

  -H                     if a command line argument is a symbolic link
                         to a directory, traverse it
  -L                     traverse every symbolic link to a directory
                         encountered
  -P                     do not traverse any symbolic links (default)

      --help     display this help and exit
      --version  output version information and exit

Owner is unchanged if missing.  Group is unchanged if missing, but changed
to login group if implied by a `:' following a symbolic OWNER.
OWNER and GROUP may be numeric as well as symbolic.

Examples:
  chown root /u        Change the owner of /u to "root".
  chown root:staff /u  Likewise, but also change its group to "staff".
  chown -hR root /u    Change the owner of /u and subfiles to "root".

Report chown bugs to [email protected]
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'chown invocation'
[root@test1 learn]#

omit [o·mit || ə'mɪt]

v.  省略, 遗漏, 疏忽  
traverse  [trav·erse || 'trævə(r)s]  
v.  横过, 经过, 穿过; 横越, 旋转, 横断  
adj.  横断的, 横的

示例：
查看

[root@test1 learn]# id daemon
uid=2(daemon) gid=2(daemon) groups=2(daemon),1(bin),4(adm),7(lp)
[root@test1 learn]#
[root@test1 learn]# grep 'wheel' /etc/group
wheel:x:10:
[root@test1 learn]# grep "wheel" /etc/group
wheel:x:10:
[root@test1 learn]#

更改

[root@test1 learn]# chown deamon:wheel mymkdir
chown: invalid user: `deamon:wheel' (拼写错误）
[root@test1 learn]# chown daemon:wheel mymkdir
[root@test1 learn]# ll
total 0
-rwxr-xr-x 1 daemon wheel 0 Jun  9 10:27 mymkdir
[root@test1 learn]#

另一种更改组的方法：

[root@test1 learn]# chgrp root mymkdir
[root@test1 learn]#
[root@test1 learn]# ll
total 0
-rwxr-xr-x 1 daemon root 0 Jun  9 10:27 mymkdir
[root@test1 learn]#