Basic introduction permissions:
Detailed rwx permissions:
rwx applied to the file:
[R]: Representative read, read, see
[W]: representative may write, can be modified, but it does not mean you can delete the file, delete a file on the premise that you have write access to the directory where the file can delete the file
[X]: represents the executable
rwx role in the directory:
[R]: Representative read, read, view contents of LS
[W]: representatives can write, you can modify, create a directory within the directory renaming + Remove +
[X]: represents the executable, you can enter the directory
Modify permission -chmod: You can modify the permissions of a file or directory
The first way: + - = change the permissions
u: Owner g: all groups o: Other Group a: all (u, g, o sum)
chmod u = rwx, g = rx, o = x filename
chmod o + w filename
chmod ax file name
The second way: by changing the digital rights
r=4,w=2,x=1,rwx=7
chmod 751 filename
Modify the file owner
chmod [-R] newowner file: change the owner of the file
chmod [-R] newowner: newgroup file: change the file owner's group and
If -R is a directory, so that all sub-files or directories recursively into force
Modify the file's group
chgrd [-R] newgroup file: change the file's group