Bash UUID

uuid.sh

#!/bin/bash

# Couldn't find a pure Bash utility for UUIDs, so I wrote this for fun (it ain't fast)

base_36_char () {
  (
    HIGH=${1:-15}
    LOW=${2:-0}
    RAND_NUM=$RANDOM

    for i in $(seq $HIGH $LOW); do
      if (( $RAND_NUM  > ((32767/16)*$i) )); then
        echo "obase=16;${i}" | bc
        break
      fi
    done
  )
}

uuid_chars () {
  (
    TIMES=$1
    HIGH=${2:-15}
    LOW=${3:-0}

    CHARS=""

    for i in $(seq 1 $TIMES); do
      CHARS+=$(base_16_char $HIGH $LOW)
    done

    echo $CHARS
  )
}

echo "$(uuid_chars 8)-$(uuid_chars 4)-4$(uuid_chars 3)-$(uuid_chars 1 11 8)$(uuid_chars 3)-$(uuid_chars 12)"