This script will create a password with 12 alphanumeric character, split into 3 parts of 4 character each, and using dash "-" as the separator

genpassword.sh

#!/bin/bash
#
# This script will create a password with 12 alphanumeric character, split into 3 parts of 4 character each, and using dash "-" as
# the separator
#
# Example: pyYq-gFcn-jRa3
#

generate_password () {

  while true
  do
    raw_string=$(base64 /dev/urandom | head -n1 | tr -cd '[:alnum:]' | cut -c-12 | grep '[0-9]')

    if [ ! -z "${raw_string}" ]; then
      final_password="${raw_string:0:4}-${raw_string:4:4}-${raw_string:8:4}"
      echo "${final_password}"
      break
    fi
  done

}

generate_password