diff --git a/lib/optimist.rb b/lib/optimist.rb
index 07a11a4..4f617a9 100644
--- a/lib/optimist.rb
+++ b/lib/optimist.rb
@@ -84,7 +84,7 @@ def self.registry_getopttype(type)
   ##  ignore options that it does not recognize.
   attr_accessor :ignore_invalid_options
 
-  DEFAULT_SETTINGS = { suggestions: true }
+  DEFAULT_SETTINGS = { suggestions: true, exact_match: true }
 
   ## Initializes the parser, and instance-evaluates any block given.
   def initialize(*a, &b)
@@ -246,6 +246,21 @@ def educate_on_error
     @educate_on_error = true
   end
 
+  ## Match long variables with inexact match.
+  ## If we hit a complete match, then use that, otherwise see how many long-options partially match.
+  ## If only one partially matches, then we can safely use that.
+  ## Otherwise, we raise an error that the partially given option was ambiguous.
+  def perform_inexact_match(arg, partial_match)  # :nodoc:
+    return @long[partial_match] if @long.has_key?(partial_match)
+    partially_matched_keys = @long.keys.select { |opt| opt.start_with?(partial_match) }
+    case partially_matched_keys.size
+    when 0 ; nil
+    when 1 ; @long[partially_matched_keys.first]
+    else ; raise CommandlineError, "ambiguous option '#{arg}' matched keys (#{partially_matched_keys.join(',')})"
+    end
+  end
+  private :perform_inexact_match
+
   def handle_unknown_argument(arg, candidates, suggestions)
     errstring = "unknown argument '#{arg}'"
     if (suggestions &&
@@ -316,10 +331,14 @@ def parse(cmdline = ARGV)
         else                       raise CommandlineError, "invalid argument syntax: '#{arg}'"
       end
 
-      sym = nil if arg =~ /--no-/ # explicitly invalidate --no-no- arguments
+      if arg.start_with?("--no-") # explicitly invalidate --no-no- arguments
+        sym = nil
+      ## Support inexact matching of long-arguments like perl's Getopt::Long
+      elsif !sym && !@settings[:exact_match] && arg.match(/^--(\S+)$/)
+        sym = perform_inexact_match(arg, $1)
+      end
 
       next nil if ignore_invalid_options && !sym
-
       handle_unknown_argument(arg, @long.keys, @settings[:suggestions]) unless sym
 
       if given_args.include?(sym) && !@specs[sym].multi?
@@ -513,7 +532,7 @@ def each_arg(args)
     until i >= args.length
       return remains += args[i..-1] if @stop_words.member? args[i]
       case args[i]
-      when /^--$/ # arg terminator
+      when "--" # arg terminator
         return remains += args[(i + 1)..-1]
       when /^--(\S+?)=(.*)$/ # long argument with equals
         num_params_taken = yield "--#{$1}", [$2]
@@ -598,7 +617,7 @@ def resolve_default_short_options!
       opts = @specs[name]
       next if type != :opt || opts.short
 
-      c = opts.long.split(//).find { |d| d !~ INVALID_SHORT_ARG_REGEX && !@short.member?(d) }
+      c = opts.long.chars.find { |d| d !~ INVALID_SHORT_ARG_REGEX && !@short.member?(d) }
       if c # found a character to use
         opts.short = c
         @short[c] = name
@@ -996,6 +1015,20 @@ def multi_arg? ; true ; end
 ##   ## if called with --monkey
 ##   p opts # => {:monkey=>true, :name=>nil, :num_limbs=>4, :help=>false, :monkey_given=>true}
 ##
+## Settings:
+##   Optimist::options and Optimist::Parser.new accept +settings+ to control how
+##   options are interpreted.  These settings are given as hash arguments, e.g:
+##
+##   opts = Optimist::options(ARGV, exact_match: false) do
+##     opt :foobar, 'messed up'
+##     opt :forget, 'forget it'
+##   end
+##
+##  +settings+ include:
+##  * :exact_match  : (default=true) Allow minimum unambigous number of characters to match a long option
+##  * :suggestions  : (default=true) Enables suggestions when unknown arguments are given and DidYouMean is installed.  DidYouMean comes standard with Ruby 2.3+
+##  Because Optimist::options uses a default argument for +args+, you must pass that argument when using the settings feature.
+##
 ## See more examples at https://www.manageiq.org/optimist
 def options(args = ARGV, *a, &b)
   @last_parser = Parser.new(*a, &b)
diff --git a/test/optimist/parser_test.rb b/test/optimist/parser_test.rb
index d492a79..c07adda 100644
--- a/test/optimist/parser_test.rb
+++ b/test/optimist/parser_test.rb
@@ -45,10 +45,12 @@ def test_synopsis
 
 
   def test_unknown_arguments
-    assert_raises(CommandlineError) { @p.parse(%w(--arg)) }
+    err = assert_raises(CommandlineError) { @p.parse(%w(--arg)) }
+    assert_match(/unknown argument '--arg'/, err.message)
     @p.opt "arg"
     @p.parse(%w(--arg))
-    assert_raises(CommandlineError) { @p.parse(%w(--arg2)) }
+    err = assert_raises(CommandlineError) { @p.parse(%w(--arg2)) }
+    assert_match(/unknown argument '--arg2'/, err.message)
   end
 
   def test_unknown_arguments_with_suggestions
@@ -779,6 +781,20 @@ def test_arguments_passed_through_block
     assert_equal @goat, boat
   end
 
+  ## test-only access reader method so that we dont have to
+  ## expose settings in the public API.
+  class Optimist::Parser
+    def get_settings_for_testing ; return @settings ;end
+  end
+
+  def test_two_arguments_passed_through_block
+    newp = Parser.new(:abcd => 123, :efgh => "other" ) do |i|
+    end
+    assert_equal newp.get_settings_for_testing[:abcd], 123
+    assert_equal newp.get_settings_for_testing[:efgh], "other"
+  end
+
+
   def test_version_and_help_override_errors
     @p.opt :asdf, "desc", :type => String
     @p.version "version"
@@ -1161,6 +1177,53 @@ def test_default_shorts_assigned_only_after_user_shorts
     assert opts[:ccd]
   end
 
+  def test_inexact_match
+    newp = Parser.new(exact_match: false)
+    newp.opt :liberation, "liberate something", :type => :int
+    newp.opt :evaluate, "evaluate something", :type => :string
+    opts = newp.parse %w(--lib 5 --ev bar)
+    assert_equal 5, opts[:liberation]
+    assert_equal 'bar', opts[:evaluate]
+    assert_nil opts[:eval]
+  end
+
+  def test_exact_match
+    newp = Parser.new()
+    newp.opt :liberation, "liberate something", :type => :int
+    newp.opt :evaluate, "evaluate something", :type => :string
+    assert_raises(CommandlineError, /unknown argument '--lib'/) do
+      newp.parse %w(--lib 5)
+    end
+    assert_raises_errmatch(CommandlineError, /unknown argument '--ev'/) do
+      newp.parse %w(--ev bar)
+    end
+  end
+
+  def test_inexact_collision
+    newp = Parser.new(exact_match: false)
+    newp.opt :bookname, "name of a book", :type => :string
+    newp.opt :bookcost, "cost of the book", :type => :string
+    opts = newp.parse %w(--bookn hairy_potsworth --bookc 10)
+    assert_equal 'hairy_potsworth', opts[:bookname]
+    assert_equal '10', opts[:bookcost]
+    assert_raises(CommandlineError) do
+      newp.parse %w(--book 5) # ambiguous
+    end
+    ## partial match causes 'specified multiple times' error
+    assert_raises(CommandlineError, /specified multiple times/) do
+      newp.parse %w(--bookc 17 --bookcost 22)
+    end
+  end
+
+  def test_inexact_collision_with_exact
+    newp = Parser.new(exact_match: false)
+    newp.opt :book, "name of a book", :type => :string, :default => "ABC"
+    newp.opt :bookcost, "cost of the book", :type => :int, :default => 5
+    opts = newp.parse %w(--book warthog --bookc 3)
+    assert_equal 'warthog', opts[:book]
+    assert_equal 3, opts[:bookcost]
+  end
+
   def test_accepts_arguments_with_spaces
     @p.opt :arg1, "arg", :type => String
     @p.opt :arg2, "arg2", :type => String
@@ -1316,6 +1379,37 @@ def test_ignore_invalid_options_stop_on_unknown_partial_mid_short
     assert opts[:arg1]
     assert_equal %w{-bu potato}, @p.leftovers
   end
+
+  # Due to strangeness in how the cloaker works, there were
+  # cases where Optimist.parse would work, but Optimist.options
+  # did not, depending on arguments given to the function.
+  # These serve to validate different args given to Optimist.options
+  def test_options_takes_hashy_settings
+    passargs_copy = []
+    settings_copy = []
+    ::Optimist.options(%w(--wig --pig), :fizz=>:buzz, :bear=>:cat) do |*passargs|
+      opt :wig
+      opt :pig
+      passargs_copy = passargs.dup
+      settings_copy = @settings
+    end
+    assert_equal [], passargs_copy
+    assert_equal settings_copy[:fizz], :buzz
+    assert_equal settings_copy[:bear], :cat
+  end
+
+  def test_options_takes_some_other_data
+    passargs_copy = []
+    settings_copy = []
+    ::Optimist.options(%w(--nose --close), 1, 2, 3) do |*passargs|
+      opt :nose
+      opt :close
+      passargs_copy = passargs.dup
+      settings_copy = @settings
+    end
+    assert_equal [1,2,3], passargs_copy
+    assert_equal(Optimist::Parser::DEFAULT_SETTINGS, settings_copy)
+  end
 end
 
 end
diff --git a/test/support/assert_helpers.rb b/test/support/assert_helpers.rb
index 558e701..e17c67a 100644
--- a/test/support/assert_helpers.rb
+++ b/test/support/assert_helpers.rb
@@ -42,5 +42,11 @@ def assert_system_exit *exp
     end
     flunk "#{msg}#{mu_pp(exp)} SystemExit expected but nothing was raised."
   end
+
+  # wrapper around common assertion checking pattern
+  def assert_raises_errmatch(err_klass, err_regexp, &b)
+    err = assert_raises(err_klass, &b)
+    assert_match(err_regexp, err.message)
+  end
 end