A simple escript for checking git repositories (on disk) against a rebar.config file

gitvsns

#!/usr/bin/env escript


%% License: http://www.mozilla.org/MPL/2.0/
%% Author: Ulf Wiger <ulf@feuerlabs.com>

-mode(compile).

main([]) ->
    {ok, Fs} = file:list_dir("."),
    {ok, Cwd} = file:get_cwd(),
    [git_vsn(F, Cwd) || F <- Fs];
main([H]) when H=="-help"; H=="-h" ->
    usage();
main(["-config", Cfg]) ->
    {ok, Cwd} = file:get_cwd(),
    case file:consult(Cfg) of
  {ok, Terms} ->
      case lists:keyfind(deps, 1, Terms) of
		{_, Deps} ->
		    Apps = find_deps(Deps),
		    lists:foreach(
		      fun({A,AppVsn,Tag}) ->
			      io:fwrite("[~w - expected: ~s / ~s]~n",
					[A,AppVsn,Tag]),
			      git_vsn(atom_to_list(A), Cwd)
		      end, Apps);
		false ->
		    io:fwrite("Cannot find deps in ~s~n", [Cfg]),
		    halt(1)
	    end;
	Error ->
	    io:fwrite("Error parsing ~p:~n~w~n", [Cfg, Error]),
	    halt(1)
    end.

%% stolen & modified from rebar_deps.erl
find_deps([App | Rest]) when is_atom(App) ->
    [{App, ".*", undefined}|find_deps(Rest)];
find_deps([{App, VsnRegex} | Rest]) when is_atom(App) ->
    [{App, VsnRegex, undefined}|find_deps(Rest)];
find_deps([{App, VsnRegex, Source} | Rest]) ->
    [{App, VsnRegex, get_vsn(Source)}|find_deps(Rest)];
find_deps([{App, VsnRegex, Source, Opts} | Rest]) when is_list(Opts) ->
    [{App, VsnRegex, get_vsn(Source)}|find_deps(Rest)];
find_deps([_|Rest]) ->
    find_deps(Rest);
find_deps([]) ->
    [].

get_vsn({hg, _Url, Rev}) -> Rev;
get_vsn({git, _Url}) -> "HEAD";
get_vsn({git, _Url, ""}) -> "HEAD";
get_vsn({git, _Url, Rev}) -> Rev;
get_vsn({bzr, _Url, Rev}) -> Rev;
get_vsn({svn, _Url, Rev}) -> Rev;
get_vsn({rsync, _Url}) -> "latest";
get_vsn({fossil, _Url}) -> "latest";
get_vsn({fossil, _Url, latest}) -> "latest";
get_vsn({fossil, _Url, Rev}) -> Rev;
get_vsn(_) -> "unknown".

usage() ->
    io:fwrite(
escript:script_name() ++ " [-config PathToRebarConfig]

This utility checks each subdirectory of the current working dir, and
lists the git version of the git repository (assuming it is in fact a
git repos).

Options:

-config PathToRebarConfig reads a given rebar.config, and lists the
  corresponding git versions for each dependent app - both the version
  expected by the rebar.config and the version derived from the git repository.
"), halt().

git_vsn(D, Cwd) ->
    case file:set_cwd(D) of
	ok ->
            Res = os:cmd("git describe --always --tags "
                         "`git log -n 1 --pretty=format:%h .`"),
	    io:fwrite("~s: ~s / ~s~n", [D, try_app_vsn(), Res]),
	    file:set_cwd(Cwd);
	_ ->
	    ignore
    end.

try_app_vsn() ->
    %% we are in the app directory
    case filelib:wildcard("ebin/*.app") of
	[AppF] ->
	    case file:consult(AppF) of
		{ok, [{application, _, Attrs}]} ->
		    proplists:get_value(vsn, Attrs, "?");
		_ ->
		    "?"
	    end;
	_ ->
	    "?"
    end.