nix-list

#!/bin/bash

# Query installed pkgs in nix store of the current user's profile
# see `man nix-store' for more info
# 
# I wrote a little `depth' helper that makes viewing the --tree output a little better

op="$1"
[[ -z "$op" ]] && op="-R"

_name () {
    fd --maxdepth 1 --type d "$1-?[^-]*$" /nix/store
}

# Args:
#   -R - shows list of installed pkgs
#   --tree - shows list of installed pkgs as ascii art tree output
_default () {
    nix-store -q $1 /nix/var/nix/profiles/per-user/$USER/profile
}

# Allows filtering the tree by how deep pkgs are
# Minimum 0 (just outputs user manifest)
# Depth 1 will show top-level pkgs (i.e. probably the ones the user installed with nix-env -i)
_depth () {

    esc=$(printf '\033')
    _gsed () { gsed -e "1 s|^\(.*\)$|${esc}[31m\1${esc}[0m|"; }

    expr='^'
    if [[ $1 -eq 0 ]]; then
        expr+='/'
    elif [[ $1 -eq 1 ]]; then
        expr+='+'

        # make sure to print first line too
        expr="\($expr\)\|\(^/\)"
    else
        for i in $(seq 1 $(($1-1))); do
            expr+='\(|\s*\)\?'
        done
        expr+='+'

        # make sure to print first line too
        expr="\($expr\)\|\(^/\)"
    fi

    # display results (including first line) inside less if necessary
    _default --tree | grep $expr | less -FX
}

if [[ "$op" == "--depth" ]]; then
    [[ -z "$2" ]] && echo "Require arg to --depth" && exit 1
    _depth $2
elif [[ "$op" == "--name" ]]; then
    _name $2
else
    _default $op
fi