vipw(8) on Linux
The text 40eceac16b5a, as Debian 7 (Wheezy) shipped it.
edit the password, group, shadow-password or shadow-group file
Flags it lists
-
--group -
--help -
--passwd -
--quiet -
--root -
--shadow -
-R -
-g -
-h -
-p -
-q -
-s