OptimistXL

$ ./examples/optional_string_arg_type.rb -h
Options:
  -l, --log=<s?>, --no-log    specify optional log-file path (Default: progname.log)
  -h, --help                  Show this message

# Note that when no options are given, :log_given is not set, but the default passes through.
$ ./examples/optional_string_arg_type.rb
{:log=>"progname.log", :help=>false}

$ ./examples/optional_string_arg_type.rb -l
{:log=>"progname.log", :help=>false, :log_given=>true}

# In this case no-log can be used to force a false value into :log
$ ./examples/optional_string_arg_type.rb --no-log
{:log=>false, :help=>false, :log_given=>true}

# Overriding the default case
$ ./examples/optional_string_arg_type.rb --log othername.log
{:log=>"othername.log", :help=>false, :log_given=>true}

$ ./examples/didyoumean.rb -h
Options:
  -c, --cone       Ice cream cone
  -z, --zippy      It zips
  -a, --zapzy      It zapz
  -b, --big-bug    Madagascar cockroach
  -h, --help       Show this message

# Suggestions for a simple misspelling

$ ./examples/didyoumean.rb --bone
Error: unknown argument '--bone'.  Did you mean: [--cone] ?.
Try --help for help.

# Letter transposition
$ ./examples/didyoumean.rb --ocne
Error: unknown argument '--ocne'.  Did you mean: [--cone] ?.
Try --help for help.

# Accidental plural

$ ./examples/didyoumean.rb --cones
Error: unknown argument '--cones'.  Did you mean: [--cone] ?.
Try --help for help.

# Two close matches, provide two suggestions.

$ ./examples/didyoumean.rb --zipzy
Error: unknown argument '--zipzy'.  Did you mean: [--zippy, --zapzy] ?.
Try --help for help.

# Posix-style options with '-' instead of '_' are a common mistake

$ ./examples/didyoumean.rb --big_bug
Error: unknown argument '--big_bug'.  Did you mean: [--big-bug] ?.
Try --help for help.

# Eventually the input option is too far away from 
# anything we know about so just say we dont understand

$ ./examples/didyoumean.rb --bugblatter-beast
Error: unknown argument '--bugblatter-beast'.
Try --help for help.

$ ./examples/partialmatch.rb -h
Options:
  -a, --apple          An apple
  -p, --apple-sauce    Cooked apple puree
  -t, --atom           Smallest unit of ordinary matter
  -n, --anvil          Heavy metal
  -e, --anteater       Eats ants
  -h, --help           Show this message

# Exact match for 'apple'
$ ./examples/partialmatch.rb --apple
{:apple=>true, :apple_sauce=>false, :atom=>false, :anvil=>false, :anteater=>false, :help=>false, :apple_given=>true}

# Cannot inexact match with 'app', as it partially matches more than one known option
$ ./examples/partialmatch.rb --app
Error: ambiguous option '--app' matched keys (apple,apple-sauce).
Try --help for help.

# Inexact match for 'apple-sauce'
$ ./examples/partialmatch.rb --apple-s
{:apple=>false, :apple_sauce=>true, :atom=>false, :anvil=>false, :anteater=>false, :help=>false, :apple_sauce_given=>true}

# Shortest match for 'anvil'
$ ./examples/partialmatch.rb --anv
{:apple=>false, :apple_sauce=>false, :atom=>false, :anvil=>true, :anteater=>false, :help=>false, :anvil_given=>true}

# Cannot inexact match with 'an', as it partially matches more than one known option
$ ./examples/partialmatch.rb --an
Error: ambiguous option '--an' matched keys (anvil,anteater).
Try --help for help.

# Shortest match for 'atom'
$ ./examples/partialmatch.rb --at
{:apple=>false, :apple_sauce=>false, :atom=>true, :anvil=>false, :anteater=>false, :help=>false, :atom_given=>true}