anchor.diff:      %% Parse getopt options
       OptSpecList = option_spec_list(),
       case getopt:parse(OptSpecList, Args) of
  -        {ok, {_Options, []}} ->
  -            %% no command to run specified
  -            help(),
  -            halt(1);
           {ok, {Options, NonOptArgs}} ->
  -            case proplists:get_bool(help, Options) of
  -                true ->
  -                    %% display help
  -                    help(),
  -                    halt(0);
  -                false ->
  -                    %% Set global variables based on getopt options
  -                    set_global_flag(Options, verbose),
  -                    set_global_flag(Options, force),
  -                    DefJobs = rebar_config:get_jobs(),
  -                    case proplists:get_value(jobs, Options, DefJobs) of
  -                        DefJobs ->
  -                            ok;
  -                        Jobs ->
  -                            rebar_config:set_global(jobs, Jobs)
  -                    end,
  -
  -                    %% Filter all the flags (i.e. strings of form key=value) from the
  -                    %% command line arguments. What's left will be the commands to run.
  -                    filter_flags(NonOptArgs, [])
  -            end;
  +            %% Check options and maybe halt execution
  +            {ok, continue} = print_help_maybe_halt(Options, NonOptArgs),
  +
  +            %% Set global variables based on getopt options
  +            set_global_flag(Options, verbose),
  +            set_global_flag(Options, force),
  +            DefJobs = rebar_config:get_jobs(),
  +            case proplists:get_value(jobs, Options, DefJobs) of
  +                DefJobs ->
  +                    ok;
  +                Jobs ->
  +                    rebar_config:set_global(jobs, Jobs)
  +            end,
  +
  +            %% Filter all the flags (i.e. strings of form key=value) from the
  +            %% command line arguments. What's left will be the commands to run.
  +            filter_flags(NonOptArgs, []);
  +
           {error, {Reason, Data}} ->
               ?ERROR("Error: ~s ~p~n~n", [Reason, Data]),
               help(),
  
positive.code:     rebar_config:set_global(Flag, Value).
  
  %%
  %% print help/usage string
  %%
  help() ->
  
negative.code:                  "[var=value,...] <command,...>",
                   [{"var=value", "rebar global variables (e.g. force=1)"},
                    {"command", "Command to run (e.g. compile)"}]).
  
  %%
  %% print known commands
  %%
  commands() ->
      io:format(<<
  "analyze                              Analyze with Dialyzer~n"
  "build_plt                            Build Dialyzer PLT~n"
  "check_plt                            Check Dialyzer PLT~n"
  "~n"
  "clean                                Clean~n"
  "compile                              Compile sources~n"
  "~n"
  "create      template= [var=foo,...]  Create skel based on template and vars~n"
  "create-app                           Create simple app skel~n"
  "create-node                          Create simple node skel~n"
  "~n"
  "generate    [dump_spec=0/1]          Build release with reltool~n"
  "install     [target=]                Install build into target~n"
  "~n"
  "eunit       [suite=foo]              Run eunit [test/foo_tests.erl] tests~n"
  "~n"
  "int_test    [suite=] [case=]         Run ct suites in ./int_test~n"
  "perf_test   [suite=] [case=]         Run ct suites in ./perf_test~n"
  "test        [suite=] [case=]         Run ct suites in ./test~n"
  >>).
  
  %%
  %% options accepted via getopt
  