command-not-found-setup.sh

# command-not-found support is now available
# for nixpkgs-unstable through nix-index

# install Nix (if you haven't already)
curl https://nixos.org/nix/install | sh

# install nix-index
nix-env -iA nixpkgs.nix-index

# generate the index (will take a little bit)
nix-index

# load command_not_found_handler for Bash
# and command_not_found_handle for Zsh
source $HOME/.nix-profile/etc/profile.d/command-not-found.sh

# try it out:
cowsay
# The program 'cowsay' is currently not installed. You can install it
# by typing:
#  nix-env -iA nixpkgs.cowsay.out
nix-env -iA nixpkgs.cowsay.out
# installing ‘cowsay-3.03+dfsg1-16’
# these paths will be fetched (0.01 MiB download, 0.03 MiB unpacked):
#   /nix/store/jqwlgxjz31mzl2zmz6fg1prvfsj2ya3v-cowsay-3.03+dfsg1-16
# fetching path ‘/nix/store/jqwlgxjz31mzl2zmz6fg1prvfsj2ya3v-cowsay-3.03+dfsg1-16’...

# *** Downloading ‘https://cache.nixos.org/nar/0hsls9ngbgd4kjacg47shcqmnjf790zmnv2w0bjkdppcrdgf928i.nar.xz’ to ‘/nix/store/jqwlgxjz31mzl2zmz6fg1prvfsj2ya3v-cowsay-3.03+dfsg1-16’...
#   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
#                                  Dload  Upload   Total   Spent    Left  Speed
# 100  9488  100  9488    0     0  23362      0 --:--:-- --:--:-- --:--:-- 23427

# building path(s) ‘/nix/store/80ig0a7rwy4a6qn7yigqac0f56swa8mj-user-environment’
# created 1389 symlinks in user environment
cowsay hello world
#  _____________ 
# < hello world >
#  ------------- 
#         \   ^__^
#          \  (oo)\_______
#             (__)\       )\/\
#                 ||----w |
#                 ||     ||

# make command-not-found available on login
echo 'source $HOME/.nix-profile/etc/profile.d/command-not-found.sh' >> $HOME/.profile