LINUX File Permissions Detailed

Ls-l//View file permissions equivalent to LL

Permission information for a file view

-rw-rw-r--1 Ceshi Ceshi 891 8 17:28 Server

Drwxrwxr-x Ceshi Ceshi 4096 17:51 www.aa.com

Start 10 characters determine the permissions for different users to manipulate files

The first character represents a file (-), a directory (d), a connection (L)

The remaining characters are set per three (RWX), read (R), write (W), execute (x)

First set of rwx: The permissions of the file owner are read, write, and execute

Second set of rw-: Permissions for users of the same group as the file owner are read, write, but cannot be executed

Third group r--: permissions for other users who are not in the same group as the file owner are read and cannot be written and executed

It can also be a numeric representation of r=4,w=2,x=1

Rwx:=>7 read, Write and execute
Rw-:=>6 Read and write. Cannot execute
R--:=>4 read-only files
R-x:=>5 Read and Execute
-w-:=>2 Write
-wx:=>3 Write, execute
--x:=>1 execution

1 indicates the number of files connected
Ceshi indicates that the user
Ceshi represents the group to which the user resides
891 indicates the size of the file (bytes)
8 17:28 Indicates the date the file was last modified
Server represents the file name

Commands to modify Permissions

chmod changing the permissions of a file or directory

chmod 755 Server gives permissions to the server Rwxr-xr-x

chmod u=rwx,g=rx,o=rx Serveru User Rights g user group permissions o different groups of other user rights

chmod u-x,g+w Server removes user-executed permissions and increases user group Write permissions

chmod a+r Server to add Read permissions to all users

Change owner (chown) and user Group (CHGRP) commands

Chown xiaoming ABC: Change the owner of ABC to Xiaoming

CHGRP Root ABC: Change the group that the ABC belongs to IS root

Chown root./ABC: Change ABC the owner of this directory is root

Chown‐r root./ABC: Change the ABC directory and the owner of all files and directories below it is root

Change the user group

When you add a user, you can specify which group to add the user to, as well as root administrative permissions to change the group in which a user resides

-USERMOD‐G Group name User name

You can use

-Usermod‐d directory name User name, change the initial directory of the user login

-Groupadd group name, adding groups to Linux

-Vi/etc/group, see all the group information in Linux, can be edited

-Cat/etc/group, view all the group information in Linux, can not be edited

-USERADD‐G group name User name, create a user and specify which group to assign the user to

-VI/ETC/PASSWD, see all user information in Linux, can be edited

-CAT/ETC/PASSWD, view all the user information in Linux, can only see can not edit

LINUX File Permissions Detailed