#!/bin/sh

find_level() {
  if [ "$1" = 1 ]; then
    pkg_info | awk '{print $1}' | while read name
    do
      grep -q '^@pkgdep' /var/db/pkg/$name/+CONTENTS || echo $name
    done > l1
    return
  fi
  
  cat l* > "s$1"
  pkg_info | awk '{print $1}' | fgrep -xvf "s$1" | while read name
  do
    awk '/^@pkgdep/ {print $2}' /var/db/pkg/$name/+CONTENTS | grep -qxvf "s$1" || echo $name
  done > "l$1"
}

i=1
find_level $i
while [ -s "l$i" ]
do
  i=$(($i+1))
  find_level $i
done