top of page
Writer's pictureMukesh Chanderia

Linux - Commands Part 12 - User modify "chage"

Updated: Aug 21, 2021

1) Add User


[root@RedHat ~]# useradd udaipur

[root@RedHat ~]# passwd udaipur

Changing password for user udaipur.

New password:

BAD PASSWORD: The password fails the dictionary check - it is based on a dictionary word

Retype new password:

passwd: all authentication tokens updated successfully.


2) To change settings of user use "usermod"


Changed userid from 1002 to 2121


[root@RedHat mail]# usermod -u 2121 mukesh

[root@RedHat mail]# grep mukesh /etc/passwd

mukesh:x:2121:1002::/home/mukesh:/bin/bash


3) To search in file with specific word


[root@RedHat ~]# getent passwd mukesh

mukesh:x:1002:1002::/home/mukesh:/bin/bash


4) Password Lock


[root@RedHat mail]# passwd -l mukesh


Locking password for user mukesh.

passwd: Success


[root@RedHat mail]# passwd -S mukesh (-S for status)

mukesh LK 2021-01-15 0 99999 7 -1 (Password locked.)


[root@RedHat mail]# passwd -u mukesh

Unlocking password for user mukesh.

passwd: Success


[root@RedHat mail]# passwd -S mukesh

mukesh PS 2021-01-15 0 99999 7 -1 (Password set, SHA512 crypt.)


5) If users are created through script then we need to set password within script file.


[root@RedHat mail]# echo RedHat@2019 | passwd --stdin mukesh

Changing password for user mukesh.

passwd: all authentication tokens updated successfully.


6) If required to remove user password so that account can be logged without password


passwd -S user


7) In /etc/passwd "/bin/bash" means user can log.


8) If you want to disable user login then assign shell /sbin/nologin


9) To change password policy use "chage"


[root@RedHat ~]# chage -l mukesh

Last password change : Jan 15, 2021

Password expires : never

Password inactive : never

Account expires : never

Minimum number of days between password change : 99

Maximum number of days between password change : 99999

Number of days of warning before password expires : 7


[root@RedHat ~]# chage mukesh

Changing the aging information for mukesh

Enter the new value, or press ENTER for the default


Minimum Password Age [99]:

Maximum Password Age [99999]:

Last Password Change (YYYY-MM-DD) [2021-01-15]: 2021-09-21

Password Expiration Warning [7]:

Password Inactive [-1]:

Account Expiration Date (YYYY-MM-DD) [-1]:


[root@RedHat ~]# chage mukesh

Changing the aging information for mukesh

Enter the new value, or press ENTER for the default



[root@RedHat ~]# chage -l mukesh

Last password change : Sep 21, 2021

Password expires : never

Password inactive : never

Account expires : never

Minimum number of days between password change : 99

Maximum number of days between password change : 99999

Number of days of warning before password expires : 7


10 ) To change home directory of user


[root@RedHat adminji]# cd india/

[root@RedHat india]# pwd

[root@RedHat india]# useradd -d /home/adminji/india/ usershell

[root@RedHat india]# ls

usershell -⇾ user directory created at /home/adminji/india rather than default /home.


11) How to change default directory while creating user


There is default file at location /etc/default/useradd

GROUP=100

HOME=/home

INACTIVE=-1

EXPIRE=

SHELL=/bin/bash

SKEL=/etc/skel

CREATE_MAIL_SPOOL=yes


If you change value here then it will become the default setting for user creation.

GROUP=100

HOME=/home/adminji/india

INACTIVE=-1

EXPIRE=

SHELL=/bin/bash

SKEL=/etc/skel

CREATE_MAIL_SPOOL=yes



12) Common hidden files for all user's home directory


[root@RedHat ~]# cd /etc/skel

bash: .l: command not found

[root@RedHat skel]# l.

. .. .bash_logout .bash_profile .bashrc



115 views0 comments

Comments


bottom of page