Random password generator in bash (and zsh)

randomPasswordGenerator.sh

# shell logger (if DEBUG = 1)
log() {
  if [[ "$DEBUG" = 1 ]]
  then
    echo " *** [`date +'%x %T'`] $*" >&2
  fi
}

# Random password generator
# 1st parameter is the length of the password (15 by default)
randomPassword() {
  # Darwin hack to sed and tr in binary data
  OLD_LC_CTYPE=$LC_CTYPE
  if [[ "`uname`" = "Darwin" ]]
  then
    LC_CTYPE=C
  fi
  # End hack

  length=15
  if [[ -n $1 ]]; then length=$1; fi
  baseLength=$(( $length * 10 ))
  randomBytes=`dd if=/dev/urandom bs=$baseLength count=1 2> /dev/null | tr '\n' ' '`
  # $ sign before the sed string means: hey shell, I want to translate that before
  password=$(sed -Ee $'s/[^\x21-\x7E]//g' <<< $randomBytes | cut -c 1-$length)
  if [[ ${#password} -lt $length ]]
  then
    password="${password}`randomPassword $(( $length - ${#password} ))`"
  fi
  log "Current length is ${#password}"
  LC_CTYPE=$OLD_LC_CTYPE # revert to original LC_CTYPE
  echo $password
}