2015/8/25 jobs: Related commands for users and groups

Related commands for users and groups

Useradd, Usermod, passwd, Userdel

Groupadd, Groupmod, GPASSWD, Groupdel

Chage, Chsh, CHFN

ID, W, who, WhoAmI

Su

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19. Permissions
Permissions: R, W, X
File:
R: Readable, can view file contents with commands like Cat
W: writable, can edit or delete this file
X: Executable, can be executed at the command prompt as a command to submit to the kernel.
Directory:
R: You can perform LS on this directory to list all internal files
W: You can create files in this directory
X: You can use the CD to switch to this directory, or you can use Ls-l to view the details of the internal files.
===========================================================================================
20, Useradd
Useradd NAME: Add user
-U UID: Specifies the primary ID of the user
-G GID: Specifies the base group ID or group name (this group must first exist to be used)
-G GID: Set additional groups (additional groups), you can specify multiple, separated from each other by commas (this additional
Group must first exist to be used)
-C "COMMENT" specifies annotation information
-d/path/to/somedirectory Specify the user's home directory, when not used by default in the home
Create a directory with the same name as the user.
-s Specifies the shell, and the path is finally the shell path specified in the Etc/shells file.
-M does not create home directories for users
-R creates a system user, a common system call, and does not establish a home directory
Userdel USERNAME: Deleting users
(The user's home directory is not deleted by default when no parameters are added)
-R: Delete the user and also delete the home directory
===========================================================================================
21. Id
ID command: View the ID information for the current user
-G USERNAME: View the user's GID
-U USERNAME: View uid of user
-G USERNAME: View all groups of users
-un: Displays the user name of the current user
-GN: Displays the group name of the current user
===========================================================================================

22, Finger
Finger command: View user account information
Finger USERNAME
===========================================================================================

24. User Account Attribute Management
Usermod: Modifying the properties of an account
usermod [option] USERNAME
-U: Modify UID
-G: Modify GID
-G: Modify additional groups
-A-G: Add additional groups without overwriting previous additional groups
-C: Modify user's comment information
-D: Know the new home directory for users
-d-m: Specify the home directory and move files from the previous home directory to the new home directory
-S: Modify the user's default shell
-L: Modify user Name
-L: Lock user account
-U: Unlock Account
==========================================================================================

25. User Password Management
passwd USERNAME
-L: Lock account
-U: Unlock Account
-D: Remove user password
-N: Minimum user password time
-x: Maximum User password usage time
PWCK: Checking user account Integrity
==========================================================================================

26. Group Management
Groupadd: New Group
groupadd [option] GROUPNAME
-g:gid specifying GID
-R: Added as System group
Groupmod: Group Properties
groupmod [option] GROUPNAME
-G GID: modifying GID
-N Name: Modify Group name
GPASSWD: Modify Group password
GPASSWD GROUPNAME
===========================================================================================


27, Chage
Chage: Change user account information
-D: Last modification time
-E: Expiration time
-I: Inactive time
-M: Minimum period
-M: Maximum age
-W: Warning time
===========================================================================================


28, Chown
Chown: Change the file owner, belong to the group, only the administrator is also this command
Chown USERNAME file .... (Change the directory itself only)
-R Recursive modification (owner of modified directory and its internal files)
--reference=/path/to/somefile file ... Set the owner of the file to the
Somefile the same as the owner (no need to designate the owner)
Chown username:grpname Fiel ... Change both the owner and the group
Chown username,grpname Fiel ... Change both the owner and the group
Chown:groupname Fiel .... Modify Genus Group
===========================================================================================


29, Chgrp
CHGRP: Modifying a file group
Chgrp GROUPNAME file .... (Change the directory itself only)
-R recursive modification (modifying the genus Group of directories and their internal files)
--reference=/path/to/somefile file ... Set the owner of the file to the
The genus of somefile (not required to designate a group)
===========================================================================================

30, chmod
chmod: Modify the file's user rights
chmod MODE File ...
-R: Recursive modification
--reference=/path/to/somefile file ...
chmod 755 File ...
Modify certain permissions for a certain type of user
U: Owner
G: Genus Group
O: Other
A: All
chmod user category =mode Fiel.
chmod U=wr,g=w/fiel.
chmod uo=wr/file.
Modify a certain bit or some bit permission for a user of a class
chmod user Category [-/+]mode fiel:

2015/8/25 jobs: Related commands for users and groups