I use a Bash Script copied from Stack Overflow:

  #!/bin/bash
  choose() { echo ${1:RANDOM%${#1}:1} $RANDOM; }

  {
      choose '!@#$%^\&'
      choose '0123456789'
      choose 'abcdefghijklmnopqrstuvwxyz'
      choose 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
      for i in $( seq 1 $(( 4 + RANDOM % 8 )) )
      do
          choose '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
      done

  } | sort -R | awk '{printf "%s",$1}'
  echo ""

https://stackoverflow.com/questions/26665389/random-password...