Soundex in Bash

COPYING

Copyright (c) 2012 Yu-Jie Lin

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

fuzzy.sh

#!/bin/bash
# Copyright (c) 2012 Yu-Jie Lin
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
# of the Software, and to permit persons to whom the Software is furnished to do
# so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

shopt -s extglob

# http://en.wikipedia.org/wiki/Soundex#Rules
soundex() {
  local s="${1,,}"
  s="${s//[^a-z]/}"
  local l="${s::1}"

  s="${s//[bfpv]/1}"
  s="${s//[cgjkqsxz]/2}"
  s="${s//[dt]/3}"
  s="${s//l/4}"
  s="${s//[mn]/5}"
  s="${s//r/6}"

  local old_s
  s="${s//w/h}"
  while [[ "$s" != "$old_s" ]]; do
    old_s="$s"
    s="${s//1?(h)1/1}"
    s="${s//2?(h)2/2}"
    s="${s//3?(h)3/3}"
    s="${s//4?(h)4/4}"
    s="${s//5?(h)5/5}"
    s="${s//6?(h)6/6}"
  done

  s="${s//[eiou]/a}"
  s="${s//1a1/11}"
  s="${s//2a2/22}"
  s="${s//3a3/33}"
  s="${s//4a4/44}"
  s="${s//5a5/55}"
  s="${s//6a6/66}"

  s="${s:1}"
  s="${s//[ayh]/}000"
  s="${l^^}${s::3}"

  ret="$s"
}


while (( $# > 0 )); do
  name="$1"
  soundex "$1"
  echo "$ret"
  shift
done

test.sh

#!/bin/bash


source fuzzy.sh


test_soundex() {
  soundex "$1"
  if [[ "$ret" == "$2" ]]; then
    printf "PASS: %-12s -> %4s\n" "$1" "$2"
    let test_pass++
  else
    printf "FAIL: %-12s -> %4s != %4s\n" "$1" "$ret" "$2"
    let test_fail++
  fi
}


tests_soundex() {
  test_pass=0
  test_fail=0
  # test cases from http://en.wikipedia.org/wiki/Soundex
  test_soundex "Robert"   "R163"
  test_soundex "Rupert"   "R163"
  test_soundex "Rubin"    "R150"
  test_soundex "Ashcraft" "A261"
  test_soundex "Ashcroft" "A261"
  test_soundex "Tymczak"  "T522"
  test_soundex "Pfister"  "P236"
  # test cases from http://tldp.org/LDP/abs/html/contributed-scripts.html
  test_soundex "Smith"    "S530"
  test_soundex "Smythe"   "S530"
  test_soundex "Harrison" "H625"
  test_soundex "Hargison" "H622"
  test_soundex "Harriman" "H655"
  # test cases from http://rosettacode.org/wiki/Soundex
  test_soundex "Soundex"     "S532"
  test_soundex "Example"     "E251"
  test_soundex "Sownteks"    "S532"
  test_soundex "Ekzampul"    "E251"
  test_soundex "Euler"       "E460"
  test_soundex "Gauss"       "G200"
  test_soundex "Hilbert"     "H416"
  test_soundex "Knuth"       "K530"
  test_soundex "Lloyd"       "L300"
  test_soundex "Lukasiewicz" "L222"
  test_soundex "Ellery"      "E460"
  test_soundex "Ghosh"       "G200"
  test_soundex "Heilbronn"   "H416"
  test_soundex "Kant"        "K530"
  test_soundex "Ladd"        "L300"
  test_soundex "Lissajous"   "L222"
  test_soundex "Wheaton"     "W350"
  test_soundex "Burroughs"   "B620"
  test_soundex "Burrows"     "B620"
  test_soundex "O'Hara"      "O600"
  test_soundex "Washington"  "W252"
  test_soundex "Lee"         "L000"
  test_soundex "Gutierrez"   "G362"
  test_soundex "Jackson"     "J250"
  test_soundex "VanDeusen"   "V532"
  # test cases from me
  test_soundex "Tomahawk"    "T520"
  echo "Tests passed: $test_pass / $(( test_pass + test_fail ))"
}


tests_soundex

TIMEFORMAT=%R
d=$((time for ((i=0; i<1000; i++)); do soundex "fuzzy" &>/dev/null; done) 2>&1)
echo "$(bc <<< "scale = 3; 1000000 * $d / 1000") us per call"

Blog post: http://blog.yjl.im/2012/03/soundex-in-bash.html