Linux Command Encyclopedia file management: chmod

Function Description: Change the permissions of a file or directory.

Grammar: chmod&http://www.aliyun.com/zixun/aggregation/37954.html ">NBSP;" [-CFRV] [--help] [--version] [< Permission range >+/-/=< permission settings ... [File or directory ...] or chmod [-cfrv][--help][--version][Digital Code] [file or directory ...] or chmod [-cfrv][--help][--reference=< reference file or directory >][--version][ File or directory ...]

Supplementary note: In the UNIX system family, the file or directory permissions control to read, write, execute 3 general permissions to distinguish, another 3 special permissions available, and then with the owner and the group to manage the scope of authority. You can use the CHMOD directive to change the permissions of files and directories by using either a literal or a digital code. The permissions for symbolic connections cannot be changed, and if you modify permissions on symbolic connections, their changes will affect the original file being connected. The notation for the scope of the permission is as follows:
U:user is the owner of a file or directory.
G:group is the group that the file or directory belongs to.
O:other, in addition to file or directory owners or groups, other users belong to this scope.
A:all, that is, all users, including owners, groups and other users.

For the section on the permission code, the list is:
R: Read permission, numeric Code "4".
W: Write permission, the number is code-named "2".
X: Execute or toggle the permission, the number is code-named "1".
-: No authority, the number is "0".
S: Special?b> Feature Description: Changes to file or directory permissions.

Parameters：
The-C or--changes effect is similar to the "-V" parameter but only returns the changed part.
The-F or--quiet or--silent does not display an error message.
-R or--recursive recursively, all files and subdirectories in the specified directory are processed together.
The-V or--verbose displays the instruction execution process.
--help online Help.
--reference=< reference file or directory > set permissions for the specified file or directory to the same permissions as the reference file or directory
--version Displays version information.
< permission settings > permission setting for a file or directory that opens a permission scope.
< permission settings > permission settings for a file or directory that closes the permission range.
< permission range >=< permission settings > This permission setting for a file or directory that specifies a permission scope.