vipw
vipw is a small computer program which enables a Unix system administrator to comfortably edit the "passwd" and "Shadow password" files. It comes bundled in the "Shadow" software package.
vigr does similar thing for /etc/group and /etc/gshadow.
References
- The vipw manpage, 26 September 1997, in the Debian passwd package version 1:4.0.13-6