Linux file attributes and permissions management

One, file properties

Use the command "Ls-al" to list all the files (directories) and their attributes in the current directory, for example:

D	Rwxr-xr-x	3	Root	Root	3242	Dec 12 09:33	Abc
1	2	3	4	5	6	7	8

1: File type, D represents the directory,-represents a normal file, B represents a block device file, C represents a character device, p represents a pipe file, and s represents a nested machine file.

2: Permission, R for Read, W for write, X for file to execute, for directory to enter this directory,-no permissions. 9 characters are divided into three groups, respectively, the owner of the file, group, and other people's permissions.

3: The number of files in the directory or the number of hard links in the file.

4: File owner.

5: Group of files.

6: If the file represents its size, the directory represents the size of the filename it contains.

7: Date modified.

8: File name or directory name.

Ii.. File permissions

There are two ways to express file permissions, one is to use R, W, X to represent the letter permission, and one is a digital permission to be represented by a number. The numeric permission converts the letter of the letter permission to a decimal number, and three sums it for a group.

R W X-

4 2 1 0

such as: Rwxr-xr-x the corresponding permission is 755.

Third, Rights management

Modify file permissions: chmod [-R] < permissions > < files >

• Change the file permissions to rw-r--r--:chmod 644 File
• Change all file permissions in Dir directory and its subdirectories to 755:chmod-r 755 dir
• To the owner of file files executable permissions (U means master, G for Group, O for others):chmod u+x file
• Deprive the host to execute permission, give group members Read permission, deprive others write permission:chomod u-x,g+r,o-w file

Modify file Owner: Chown [-R] < account > < file >

• Modify file's owner to LxW:chown LxW file
• Recursive modification of all files under Dir directory the owner is LxW:chown-r LxW dir

Modify file groups: Chgrp [-r] < groups > < files >

• Modify file group to class:chgrp class file
• Recursively modify all the file groups in the Dir directory as class:Chgrp-r class dir

Linux file properties and Rights management