vigr

Edit the group file

$ vigr

$ vigr [[-V|--version]]

vigr [-n] [-s]

-n
    Disable the shadow password suite. This option is mainly useful on systems that do not use shadow passwords.

-s
    Edit the shadow password file (/etc/shadow) instead of the password file (/etc/passwd).

The vigr command is a utility in Linux systems used to edit the /etc/group, /etc/passwd, and /etc/shadow files in a safe and controlled manner. It locks these files while being edited to prevent corruption by concurrent modifications. vigr ensures that only one user can edit these vital system files simultaneously, safeguarding the integrity of user account and group information.

Unlike direct editing with a text editor, vigr uses a temporary copy of the file, and upon saving, it checks for any changes made by other processes in the meantime. If conflicts are detected, the user is prompted to resolve them. This mechanism is essential for maintaining system stability and preventing data loss. The default editor used by vigr is typically determined by the $EDITOR environment variable, or vi if $EDITOR is not set.

Directly manipulating the shadow file requires elevated privileges (usually root). Using the wrong editor or misconfiguring the files can severely compromise system security and user access.

Careless use of vigr can have serious security consequences. Always ensure that you are editing the correct file and that the changes made are consistent with your intended outcome. Backups are strongly recommended before making modifications.

vigr has been part of Unix-like systems for a long time. It arose from the need for a safe way to edit the system's user and group databases, preventing concurrent writes from corrupting these critical files. The command's development has focused on ensuring atomicity and conflict resolution during editing sessions.

vipw(8), groupadd(8), useradd(8), shadow(5), passwd(5)