Rename file names and contents

translate.fish

#!/usr/bin/env fish

for tool in ack rename perl
  if not which $tool >/dev/null
    echo You need $tool to run this tool >&2
    exit 1
  end
end

if [ (count $argv) != 3 ]
  echo USAGE: translate FROM TO FILE_OR_DIRECTORY >&2
  exit 1
end

set -l from $argv[1]
set -l to $argv[2]
set -l target $argv[3]

function tolower
  echo $argv | tr [A-Z] [a-z]
end

function toupper
  echo $argv | tr [a-z] [A-Z]
end

function capitalize
  tolower $argv | sed 's/^./\U&/; s/[^a-zA-Z0-9]./\U&/g'
end

function parameterize
  set -l c ""
  if [ (count $argv) = 1 ]
    set c $argv[1]
  end
  sed 's/[^a-zA-Z0-9]/'$c'/g'
end

function pascalize
  capitalize $argv | parameterize
end

function camelize
  pascalize $argv | sed 's/^./\L&/'
end

function wikipedify
  echo $argv | parameterize _
end

function hyphenate
  echo $argv | parameterize -
end

set -l lowercase 's/\Q'(tolower $from)'\E/\Q'(tolower $to)'\E/g'
set -l uppercase 's/\Q'(toupper $from)'\E/\Q'(toupper $to)'\E/g'
set -l capitalized 's/\Q'(capitalize $from)'\E/\Q'(capitalize $to)'\E/g'

set -l replace "$lowercase ; $uppercase ; $capitalized"

# more than one word
if echo $from | grep [^a-zA-Z0-9]
  set -l pascalcase 's/\Q'(pascalize $from)'\E/\Q'(pascalize $to)'\E/g'
  set -l camelcase 's/\Q'(camelize $from)'\E/\Q'(camelize $to)'\E/g'
  set -l underline_lowercase 's/\Q'(wikipedify $lowercase[1])'\E/\Q'(wikipedify $lowercase[2])'\E/g'
  set -l underline_uppercase 's/\Q'(wikipedify $uppercase[1])'\E/\Q'(wikipedify $uppercase[2])'\E/g'
  set -l hyphenated_lowercase 's/\Q'(hyphenate $lowercase[1])'\E/\Q'(hyphenate $lowercase[2])'\E/g'
  set -l hyphenated_uppercase 's/\Q'(hyphenate $uppercase[1])'\E/\Q'(hyphenate $uppercase[2])'\E/g'

  set replace "$replace ; $pascalcase ; $camelcase ; $underline_lowercase ; $underline_uppercase ; $hyphenated_lowercase ; $hyphenated_uppercase"
end

if [ -d $target ]
  pushd $target
  rename "$replace" **
  ack -f --nopager | xargs perl -p -e "$replace" -i
  popd
else
  rename "$replace" $target
  perl -p -e "$replace" -i $target
end

Using it to compare differences between rbenv and pyenv:

git clone https://github.com/sstephenson/rbenv
git clone https://github.com/yyuu/pyenv
./translate.fish rbenv pyenv rbenv
./translate.fish ruby pythong rbenv
./translate.fish sstephenson yyuu rbenv
meld rbenv pyenv