vipw, vigr - edit the password, group, shadow-password or shadow-group file
The vipw and vigr commands edits the files /etc/passwd and /etc/group, respectively. With the -s flag, they will edit the shadow versions of those files, /etc/shadow and /etc/gshadow, respectively. The programs will set the appropriate locks to prevent file corruption. When looking for an editor, the programs will first try the environment variable $VISUAL, then the environment variable $EDITOR, and finally the default editor, vi(1).
The options which apply to the vipw and vigr commands are:
Edit group database.
Display help message and exit.
Edit passwd database.
-R, --root CHROOT_DIR
Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.
Edit shadow or gshadow database.
Editor to be used.
Editor to be used if VISUAL is not set.
Group account information.
Secure group account information.
User account information.
Secure user account information.