diff --git a/README.md b/README.md
index da9755e..828251b 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 # scripts
 
-A collection of scripts that contain useful utilities and functions.
+A collection of scripts that contain useful utilities and functions. 
+Most scripts are written for bash/zsh shell in mind, although some are Ruby files which will need the Ruby interpreter to function.
 
-On Linux, run `setup.sh` with admin privileges to automatically copy over shell scripts into `/usr/local/bin`.
+On Linux, run `setup.sh` with admin privileges to automatically copy over these scripts into `/usr/local/bin`.
diff --git a/setup.sh b/setup.sh
index 0245b91..7d63afc 100644
--- a/setup.sh
+++ b/setup.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
-for file in src/*.sh; do
-  cp "$file" "${file%.sh}"
+for file in src/*.{sh,rb}; do
+  [ -e "$file" ] || continue
+  cp "$file" "${file%.*}"
 done
diff --git a/src/sharpener.rb b/src/sharpener.rb
new file mode 100755
index 0000000..5bf4e36
--- /dev/null
+++ b/src/sharpener.rb
@@ -0,0 +1,66 @@
+#!/usr/bin/env ruby
+
+require "find"
+require "openssl"
+
+$duplicates_increment = 0
+$files_increment = 0
+
+##
+# Logs progress finding duplicates to stdout.
+#
+# @param is_duplicate A boolean indicating if the progress to be logged includes a duplicate file or not.
+def log_duplicate_progress(is_duplicate:)
+  $duplicates_increment += 1 if is_duplicate
+
+  print "\r#{$duplicates_increment} duplicates / #{$files_increment} files scanned"
+  $files_increment += 1
+end
+
+##
+# Finds all duplicates—recursively—within the supplied target directory. Ignores any directories or files that are
+# prefixed with a period character.
+#
+# @param target The string that represents the path to the target directory.
+#
+def find_dupes(target)
+  duplicates = {}
+
+  Find.find(target) do |path|
+    Find.prune if File.basename(path).start_with?(".")
+
+    if FileTest.file?(path)
+      digest = OpenSSL::Digest::SHA256.file(path).hexdigest
+
+      log_duplicate_progress(is_duplicate: duplicates.key?(digest))
+
+      duplicates[digest] = [] unless duplicates.key?(digest)
+      duplicates[digest] << path
+    end
+  end
+
+  STDOUT.puts "\n==="
+  duplicates.select { |k, v| v.size > 1 }.each do |k, v|
+    STDOUT.puts "duplicate: #{k}"
+    STDOUT.puts "#{v}"
+  end
+end
+
+##
+# Given a source directory, find all files in source directory that are not present in the target directory. Ignores any
+# directories or files that are prefixed with a period character.
+#
+# @param source
+# @param target
+#
+def find_unqiues(source, target); end
+
+case ARGV[0]
+when "duplicates"
+  find_dupes(ARGV[1])
+when "uniques"
+  find_uniques(ARGV[1], ARGV[2])
+else
+  STDERR.puts "Please provide either 'duplicates' or 'uniques' to 'sharpener'."
+  exit(1)
+end
\ No newline at end of file