Shell script that rolls a single die

rolldie.sh

#!/bin/sh

random() {
  od -A n -t d -N 1 /dev/random | tr '\n' ' ' | awk '{print $1}'
}

rolldie() {
  local r=$(random)
  while [ $r -gt 6 -o $r -lt 1 ]; do
    r=$(random)
  done
  echo $r
}

rolldie