vipw -s & vigr -s Command use in Linux & Ubuntu for editing /etc/passwd, shadow, and group files / The best way to edit /etc/passwd, shadow, and group files.

The best way to edit /etc/passwd, or shadow or group file is to use vipw command. Traditionally (under UNIX and Linux) if you use vi to edit /etc/passwd file and same time a user try to change a password while root editing file, then the user’s change will not entered into file. To avoid this problem and to put a lock while editing file, use vipw and vigr command which will edit the files /etc/passwd and /etc/group respectively. If you pass -s option to these command, then they will edit the shadow versions of those files i.e. /etc/shadow and /etc/gshadow, respectively.

The main purpose of locks is to prevent file corruption. Do not use vi or other text editor to edit password file. Syntax:

• vipw -s : Edit /etc/passwd file

• vigr -s : Edit /etc/group file

Where,

• -s : Secure file editing

An example :-

Login as a root user:

 [root@linuxbiginner ~]# vipw -s 

On other terminal login as normal user (for example anurag) and issue command passwd to change anurag’s password:

[anurag@linuxbiginner ~]# passwd
Changing password for user anurag.
Changing password for anurag.
(current) UNIX password:
New password:
Retype new password:
passwd: authentication tokens lock busy.

As you see it returned with an error “passwd: Authentication token lock busy”

This will avoid /etc/shadow file corruption.