chgrp 改变所属群组
chgrp命令可以变更文件或目录所属群组,当然,要被改变的组名必须要在/etc/group文件内存在才行。
chgrp基本参数:
1 root@ubuntu:~# chgrp --help 2 Usage: chgrp[OPTION]... GROUP FILE... 3 or: chgrp [OPTION]... --reference=RFILE FILE... 4 Change the group of each FILE to GROUP. 5 With --reference, change the group of each FILE to that of RFILE. 6 7 -c, --changes like verbose but report only when a change is made 8 --dereference affect the referent of each symbolic link (this is 9 the default), rather than the symbolic link itself 10 -h, --no-dereference affect each symbolic link instead of any referenced 11 file(useful only on systems that can change the 12 ownership of a symlink) 13 --no-preserve-root do not treat `/'specially (the default) 14 --preserve-root fail to operate recursively on `/' 15 -f, --silent, --quiet suppress most error messages 16 --reference=RFILE use RFILE's group rather than specifying a 17 GROUP value 18 -R, --recursive operate on files and directories recursively 19 -v, --verbose output a diagnostic for every file processed
范例1,新建文件test.txt,并将其所属群组改为gboy:
1 root@ubuntu:~# touchtest.txt <==新建文件test.txt 2 root@ubuntu:~# ls -l 3 total 0 4 -rw-r--r-- 1 root root 0 2015-07-19 02:24test.txt <==所属群组为root 5 root@ubuntu:~# chgrpgboy test.txt 6 root@ubuntu:~# ls -l 7 total 0 8 -rw-r--r-- 1 root gboy 0 2015-07-19 02:24 test.txt <==所属群组成功改为gboy
*可以发现,test.txt的所属群组成功从root改为gboy(被改变的组名必须要在/etc/group文件中存在,否则会报错)
有时候,我们会需要改变指定目录以及其子目录下的所有文件的群组属性,这个时候就需要加上-R参数,进行递归的持续更改。
范例2,新建文件夹test,在其内新建文件test1.txt,test2.txt,更改其目录以及其子目录下的所有文件的群组属性:
1 root@ubuntu:~# mkdirtest <==新建文件夹test 2 root@ubuntu:~# cd test/ 3 root@ubuntu:~/test# touchtest1.txt <==新建文件test1.txt 4 root@ubuntu:~/test# touchtest2.txt 5 root@ubuntu:~/test# ls -l 6 total 0 7 -rw-r--r-- 1 root root 0 2015-07-19 02:42test1.txt <== 文件所属群组root 8 -rw-r--r-- 1 root root 0 2015-07-19 02:42test2.txt 9 root@ubuntu:~/test# cd 10 root@ubuntu:~# chgrp -R gboy test 11 root@ubuntu:~# ls -l 12 total 4 13 drwxr-xr-x 2 root gboy 4096 2015-07-19 02:42test <==文件夹test的所属群组成功改为gboy 14 root@ubuntu:~# cd test 15 root@ubuntu:~/test# ls -l 16 total 0 17 -rw-r--r-- 1 root gboy 0 2015-07-19 02:42test1.txt 18 -rw-r--r-- 1 root gboy 0 2015-07-19 02:42 test2.txt <==test1.txt和test2.txt所属群组成功改为gboy
chown 改变文件所有者
chown命令可以将指定文件的所有者改为指定的用户或组,普通用户不能将自己的文件改变成其他的拥有者。其操作权限一般为管理员。
chown基本参数:
1 root@ubuntu:~# chown --help 2 Usage: chown[OPTION]... [OWNER][:[GROUP]] FILE... 3 or: chown [OPTION]... --reference=RFILE FILE... 4 Change the owner and/or group of each FILE to OWNER and/or GROUP. 5 With --reference, change the owner and group of each FILE to those of RFILE. 6 7 -c, --changes like verbose but report only when a change is made 8 --dereference affect the referent of each symbolic link (this is 9 the default), rather than the symbolic link itself 10 -h, --no-dereference affect each symbolic link instead of any referenced 11 file(useful only on systems that can change the 12 ownership of a symlink) 13 --from=CURRENT_OWNER:CURRENT_GROUP 14 change the owner and/or group of each file only if 15 its current owner and/or group match those specified 16 here. Either may be omitted, in which casea match 17 is not required forthe omitted attribute 18 --no-preserve-root do not treat `/'specially (the default) 19 --preserve-root fail to operate recursively on `/' 20 -f, --silent, --quiet suppress most error messages 21 --reference=RFILE use RFILE's owner and group rather than 22 specifying OWNER:GROUP values 23 -R, --recursive operate on files and directories recursively 24 -v, --verbose output a diagnostic for every file processed
范例1,改变文件test.txt的拥有者为gboy
1 root@ubuntu:~# touch test.txt <==新建文件test.txt 2 root@ubuntu:~# ls -l 3 total 0 4 -rw-r--r-- 1 root root 0 2015-07-19 02:24 test.txt <==拥有者为root 5 root@ubuntu:~# chowngboy test.txt 6 root@ubuntu:~# ls -l 7 total 0 8 -rw-r--r-- 1 gboy root 0 2015-07-19 02:53 test.txt <==拥有者变为gboy
范例2,改变文件test.txt的拥有者改为gboy,群组改为users
1 root@ubuntu:~# touchtest.txt 2 root@ubuntu:~# ls -l 3 total 0 4 -rw-r--r-- 1 root root 0 2015-07-19 02:58test.txt 5 root@ubuntu:~# chowngboy:users test.txt <==":"前面是拥有者,后面是群组 6 root@ubuntu:~# ls -l 7 total 0 8 -rw-r--r-- 1 gboy users 0 2015-07-19 02:58 test.txt
范例3,将范例2中test.txt的拥有者和群组都改为root
1 root@ubuntu:~# chownroot: test.txt 2 root@ubuntu:~# ls -l 3 total 0 4 -rw-r--r-- 1 root root 0 2015-07-19 02:58 test.txt
范例4,将范例3中test.txt群组改为users
1 -rw-r--r-- 1 root root 0 2015-07-19 02:58test.txt 2 root@ubuntu:~# chown:users test.txt 3 root@ubuntu:~# ls -l 4 total 0 5 -rw-r--r-- 1 root users 0 2015-07-19 02:58 test.txt
范例5,改变目录以及其子目录下的所有文件的拥有者和群组
1 root@ubuntu:~# mkdirtest <==创建文件夹test 2 root@ubuntu:~# ls -l 3 total 4 4 drwxr-xr-x 2 root root 4096 2015-07-19 03:56test <==test文件夹的拥有者和群组都为root 5 root@ubuntu:~# cd test 6 root@ubuntu:~/test# touchtest1.txt <== 创建文件test1.txt,test2.txt 7 root@ubuntu:~/test# touchtest2.txt 8 root@ubuntu:~/test# ls -l 9 total 0 10 -rw-r--r-- 1 root root 0 2015-07-19 03:56test1.txt <== test1.txt和test2.txt的拥有者和群组都为root 11 -rw-r--r-- 1 root root 0 2015-07-19 03:56test2.txt 12 root@ubuntu:~/test# cd 13 root@ubuntu:~# chown -R -v gboy:users test <==改变权限的命令 14 changed ownership of `test/test2.txt'to gboy:users 15 changed ownership of `test/test1.txt'to gboy:users 16 changed ownership of `test'to gboy:users 17 root@ubuntu:~# ls -l 18 total 4 19 drwxr-xr-x 2 gboy users 4096 2015-07-19 03:56test <==test文件夹的拥有者变为gboy,群组变为users 20 root@ubuntu:~# cd test 21 root@ubuntu:~/test# ls -l 22 total 0 23 -rw-r--r-- 1 gboy users 0 2015-07-19 03:56test1.txt <==test1.txt和test2.txt的拥有者变为gboy,群组变为users 24 -rw-r--r-- 1 gboy users 0 2015-07-19 03:56 test2.txt
*chown -R -v gboy:users test中,-R是进行递归的持续更改,-V是显示详细的处理信息,表示将test目录以及其子目录下的test1.txt和test2.txt的拥有者改为gboy,群组改为users
chmod 改变文件权限
chmod命令用于改变Linux系统文件或目录的访问权限。权限的设置方法有两种,分别可以用数字或者符号进行权限的更改
基本参数:
1 root@ubuntu:~# chmod --help 2 Usage: chmod[OPTION]... MODE[,MODE]... FILE... 3 or: chmod [OPTION]... OCTAL-MODE FILE... 4 or: chmod [OPTION]... --reference=RFILE FILE... 5 Change the mode of each FILE to MODE. 6 7 -c, --changes like verbose but report only when a change is made 8 --no-preserve-root do not treat `/'specially (the default) 9 --preserve-root fail to operate recursively on `/' 10 -f, --silent, --quiet suppress most error messages 11 -v, --verbose output a diagnostic for every fileprocessed 12 --reference=RFILE use RFILE's mode instead of MODE values 13 -R, --recursive change files and directories recursively 14 --help display this help and exit 15 --version output version information and exit 16 17 Each MODE is of the form `[ugoa]*([-+=]([rwxXst]*|[ugo]))+'.
(1)数字类型改变文件权限
Linux中的文件有9个基本权限,分别是user(拥有者)、group(群组)、others(其他)三种身份,每种身份有各自的r(read)、w(write)、x(executive)三个权限。
数字与字符对应关系为:r=4,w=2,x=1 (若要rwx属性则4+2+1=7,若要rw-属性则4+2=6,若要r-x属性则4+1=7)
例:当权限为[-rwxr-xr-x]时,user=rwx=4+2+1=7,group=r-x=4+1=5,others=r-x=4+1=5,则文件权限问755
*r(read):可读取文件的实际内容
w(write):可以编辑、新增或者修改文件的内容(不包括删除文件)
x(execute):该文件具有可以被系统执行的权限
范例1,启用test.txt文件的所有权限(即权限为[-rwxrwxrwx]):
1 root@ubuntu:~# touchtest.txt 2 root@ubuntu:~# ls -l 3 total 0 4 -rw-r--r-- 1 root root 0 2015-07-19 04:29test.txt <==可以发现test.txt权限为[-rw-r--r--],即644 5 root@ubuntu:~# chmod 777test.txt 6 root@ubuntu:~# ls -l 7 total 0 8 -rwxrwxrwx 1 root root 0 2015-07-19 04:29 test.txt <==权限改为了[-rwxrwxrwx]
(2)数字类型改变文件权限
由上面的介绍可知,Linux文件有user,group,others三种身份,那么我们可以通过u,g,o来代表三种身份的权限,此外,a代表all,即全部的身份。所以,设置权限也可以用以下方式
chmod | u g o a | +(加入) -(除去) =(设置) | 文件或目录 |
范例1,将test.txt文件的权限设置为[-rwxrw-r--]
1 root@ubuntu:~# ls -l 2 total 0 3 -rwxrwxrwx 1 root root 0 2015-07-19 04:29test.txt 4 root@ubuntu:~# chmod u=rwx,g=rw,o=r test.txt 5 root@ubuntu:~# ls -l 6 total 0 7 -rwxrw-r-- 1 root root 0 2015-07-19 04:29 test.txt
范例2,将test.txt文件的权限设置为[-rwxrw-rw-]
1 root@ubuntu:~# chmod u=rwx,go=rw test.txt 2 root@ubuntu:~# ls -l 3 total 0 4 -rwxrw-rw- 1 root root 0 2015-07-19 04:29 test.txt
范例3,去掉test.txt所以身份的w权限
1 root@ubuntu:~# ls -l 2 total 0 3 -rwxrw-rw- 1 root root 0 2015-07-19 04:29test.txt 4 root@ubuntu:~# chmod a-wtest.txt 5 root@ubuntu:~# ls -l 6 total 0 7 -r-xr--r-- 1 root root 0 2015-07-19 04:29 test.txt
范例4,增加user的w权限,去掉others的r权限
1 root@ubuntu:~# ls -l 2 total 0 3 -r-xr--r-- 1 root root 0 2015-07-19 04:29test.txt 4 root@ubuntu:~# chmod u+w,o-r test.txt 5 root@ubuntu:~# ls -l 6 total 0 7 -rwxr----- 1 root root 0 2015-07-19 04:29 test.txt