Passphrase generator for linux based on /dev/urandom and dict words available in linux

passphrase_gen.bash

#!/bin/bash
# Usage: ./passphrase_gen.bash 4 > x && vim x
# We redirect to file and print via vim so no history is saved anywhere.
# Repeat after you get passphrase you like. Memorize it/write it down
# and remove x afterwards.
set -eo pipefail

words=/usr/share/dict/words

# https://serverfault.com/a/214620/216850
sudo rngd -r /dev/urandom

n=$1

# print $n randomly chosen words from $words file
for i in $(seq 1 $n); do
  # https://unix.stackexchange.com/a/268960
  random=$(od -vAn -N4 -tu4 < /dev/urandom)

  lines=$(cat $words | wc -l)

  line=$((random % lines))
  awk "NR==$line" $words
done