.TH ADD-SHELL 8 "23 Sep 2021" .SH NAME add-shell \- add shells to the list of valid login shells .SH SYNOPSIS .B add-shell .I shellname .RI [ shellname ...] .SH DESCRIPTION .B add-shell copies .I /etc/shells to .IR /etc/shells.tmp , adds the given shells to this file if they are not already present, and copies this temporary file back to .IR /etc/shells . .sp 1 The shells must be provided by their full pathnames. .SH "ENVIRONMENT" .TP .I DPKG_ROOT specifies the base path under which .I /etc/shells resides. .SH SEE ALSO .BR shells (5)