Find all anagrams in the system's dictionary

anagrams.sh

#!/bin/sh
#
# Find all anagrams in the system's dictionary by mapping the words
# into a product of prime numbers associated with each letter
#

# Process plain ASCII characters
export LC_ALL=C

# Create commands for the calculator bc
{
  # Obtain numbers from 1 to 200
  seq 1 200 |
    # Factorize them to find primes
    factor |
    # Assign prime numbers to variables a-z
    awk 'BEGIN { n = 97 } NF == 2 {printf("%c = %s\n", n++, $2)}' |
    head -26

  # Process system dictionary
  sed -n '
    # Obtain lowercase words
    /^[a-z]*$/ {
    # Save word
    h
    # Convert it into a bc command that will print it
    s/.*/"& "/
    p
    # Retrieve word
    g
    # Convert word into variable multiplications, e.g. h * e * l * l * o
    s/./ * &/g
    s/..//
    p
  }' /usr/share/dict/words
} |
  # Process commands with bc
  bc |
  # Save produced map from words into a product of primes
  tee map |
  # Obtain only the products
  cut -d ' ' -f 2 |
  # Sort them
  sort |
  # Obtain duplicate products
  uniq -d |
  # Find those products as words in the map
  fgrep -wf - map |
  # Order result by the product
  sort -k 2n