Recursively remove homebrew packages

brew-zap

#!/bin/zsh

set -euo pipefail

local preall=$(brew list -1)
local predeps=$(brew deps --installed)
local preleaves=$(brew leaves)

recur() {
        local pkg=$1
        local deps=$(echo "$predeps"|grep "^$pkg:"|cut -d':' -f2|xargs|tr ' ' '\n')
        echo "> Zapping $pkg..."
        brew uninstall "$pkg" || {
                if echo "$preall"|grep -q "^$pkg$"; then
                        echo "> Package depended on by another package, skipping."
                        return
                fi
        }
        echo "Dependencies: $(echo "$deps"|tr '\n' ',')"
        test -z "$deps" || {
                echo $deps|while read dep; do
                        if ! echo $preleaves|grep -q $dep; then
                                recur "$dep"
                        else
                                echo "> Skipping $dep as it was a leaf before."
                        fi
                done
        }
}

recur "$1"