%%% vi:ts=4 sw=4 et %%%------------------------------------------------------------------- %%% @copyright (C) 2011, Erlware LLC %%% @doc %%% Helper functions for working with files. %%% @end %%%------------------------------------------------------------------- -module(ec_file). -export([ exists/1, copy/2, copy/3, copy_file_info/3, insecure_mkdtemp/0, mkdir_path/1, mkdir_p/1, find/2, is_symlink/1, is_dir/1, type/1, real_dir_path/1, remove/1, remove/2, md5sum/1, sha1sum/1, read/1, write/2, write_term/2 ]). -export_type([ option/0 ]). -include_lib("kernel/include/file.hrl"). -define(CHECK_PERMS_MSG, "Try checking that you have the correct permissions and try again~n"). %%============================================================================ %% Types %%============================================================================ -type file_info() :: mode | time | owner | group. -type option() :: recursive | {file_info, [file_info()]}. %%%=================================================================== %%% API %%%=================================================================== -spec exists(file:filename()) -> boolean(). exists(Filename) -> case file:read_file_info(Filename) of {ok, _} -> true; {error, _Reason} -> false end. %% @doc copy an entire directory to another location. -spec copy(file:name(), file:name(), Options::[option()]) -> ok | {error, Reason::term()}. copy(From, To, []) -> copy_(From, To, []); copy(From, To, Options) -> case proplists:get_value(recursive, Options, false) of true -> case is_dir(From) of false -> copy_(From, To, Options); true -> make_dir_if_dir(To), copy_subfiles(From, To, Options) end; false -> copy_(From, To, Options) end. %% @doc copy a file including timestamps,ownership and mode etc. -spec copy(From::file:filename(), To::file:filename()) -> ok | {error, Reason::term()}. copy(From, To) -> copy_(From, To, [{file_info, [mode, time, owner, group]}]). copy_(From, To, Options) -> Linked = case file:read_link(From) of {ok, Linked0} -> Linked0; {error, _} -> undefined end, case Linked =/= undefined orelse file:copy(From, To) of true -> file:make_symlink(Linked, To); {ok, _} -> copy_file_info(To, From, proplists:get_value(file_info, Options, [])); {error, Error} -> {error, {copy_failed, Error}} end. copy_file_info(To, From, FileInfoToKeep) -> case file:read_file_info(From) of {ok, FileInfo} -> case write_file_info(To, FileInfo, FileInfoToKeep) of [] -> ok; Errors -> {error, {write_file_info_failed_for, Errors}} end; {error, RFError} -> {error, {read_file_info_failed, RFError}} end. write_file_info(To, FileInfo, FileInfoToKeep) -> WriteInfoFuns = [{mode, fun try_write_mode/2}, {time, fun try_write_time/2}, {group, fun try_write_group/2}, {owner, fun try_write_owner/2}], lists:foldl(fun(Info, Acc) -> case proplists:get_value(Info, WriteInfoFuns, undefined) of undefined -> Acc; F -> case F(To, FileInfo) of ok -> Acc; {error, Reason} -> [{Info, Reason} | Acc] end end end, [], FileInfoToKeep). try_write_mode(To, #file_info{mode=Mode}) -> file:write_file_info(To, #file_info{mode=Mode}). try_write_time(To, #file_info{atime=Atime, mtime=Mtime}) -> file:write_file_info(To, #file_info{atime=Atime, mtime=Mtime}). try_write_owner(To, #file_info{uid=OwnerId}) -> file:write_file_info(To, #file_info{uid=OwnerId}). try_write_group(To, #file_info{gid=OwnerId}) -> file:write_file_info(To, #file_info{gid=OwnerId}). %% @doc return the MD5 digest of a string or a binary, %% named after the UNIX utility. -spec md5sum(string() | binary()) -> string(). md5sum(Value) -> bin_to_hex(crypto:hash(md5, Value)). %% @doc return the SHA-1 digest of a string or a binary, %% named after the UNIX utility. -spec sha1sum(string() | binary()) -> string(). sha1sum(Value) -> bin_to_hex(crypto:hash(sha, Value)). bin_to_hex(Bin) -> hex(binary_to_list(Bin)). %% @doc delete a file. Use the recursive option for directories. %% 
%% Example: remove("./tmp_dir", [recursive]).
%%
-spec remove(file:name(), Options::[option()]) -> ok | {error, Reason::term()}. remove(Path, Options) -> case lists:member(recursive, Options) of false -> file:delete(Path); true -> remove_recursive(Path, Options) end. %% @doc delete a file. -spec remove(file:name()) -> ok | {error, Reason::term()}. remove(Path) -> remove(Path, []). %% @doc indicates with a boolean if the path supplied refers to symlink. -spec is_symlink(file:name()) -> boolean(). is_symlink(Path) -> case file:read_link_info(Path) of {ok, #file_info{type = symlink}} -> true; _ -> false end. is_dir(Path) -> case file:read_file_info(Path) of {ok, #file_info{type = directory}} -> true; _ -> false end. %% @doc returns the type of the file. -spec type(file:name()) -> file | symlink | directory | undefined. type(Path) -> case filelib:is_regular(Path) of true -> file; false -> case is_symlink(Path) of true -> symlink; false -> case is_dir(Path) of true -> directory; false -> undefined end end end. %% @doc gets the real path of a directory. This is mostly useful for %% resolving symlinks. Be aware that this temporarily changes the %% current working directory to figure out what the actual path %% is. That means that it can be quite slow. -spec real_dir_path(file:name()) -> file:name(). real_dir_path(Path) -> {ok, CurCwd} = file:get_cwd(), ok = file:set_cwd(Path), {ok, RealPath} = file:get_cwd(), ok = file:set_cwd(CurCwd), filename:absname(RealPath). %% @doc make a unique temporary directory. Similar function to BSD stdlib %% function of the same name. -spec insecure_mkdtemp() -> TmpDirPath::file:name() | {error, term()}. insecure_mkdtemp() -> UniqueNumber = erlang:integer_to_list(erlang:trunc(rand:uniform() * 1_000_000_000_000)), TmpDirPath = filename:join([tmp(), lists:flatten([".tmp_dir", UniqueNumber])]), case mkdir_path(TmpDirPath) of ok -> TmpDirPath; Error -> Error end. %% @doc Makes a directory including parent dirs if they are missing. -spec mkdir_p(file:name()) -> ok | {error, Reason::term()}. mkdir_p(Path) -> %% We are exploiting a feature of ensuredir that that creates all %% directories up to the last element in the filename, then ignores %% that last element. This way we ensure that the dir is created %% and not have any worries about path names DirName = filename:join([filename:absname(Path), "tmp"]), filelib:ensure_dir(DirName). %% @doc Makes a directory including parent dirs if they are missing. -spec mkdir_path(file:name()) -> ok | {error, Reason::term()}. mkdir_path(Path) -> mkdir_p(Path). %% @doc read a file from the file system. Provide UEX exception on failure. -spec read(FilePath::file:filename()) -> {ok, binary()} | {error, Reason::term()}. read(FilePath) -> %% Now that we are moving away from exceptions again this becomes %% a bit redundant but we want to be backwards compatible as much %% as possible in the api. file:read_file(FilePath). %% @doc write a file to the file system. Provide UEX exception on failure. -spec write(FileName::file:filename(), Contents::string()) -> ok | {error, Reason::term()}. write(FileName, Contents) -> %% Now that we are moving away from exceptions again this becomes %% a bit redundant but we want to be backwards compatible as much %% as possible in the api. file:write_file(FileName, Contents). %% @doc write a term out to a file so that it can be consulted later. -spec write_term(file:filename(), term()) -> ok | {error, Reason::term()}. write_term(FileName, Term) -> write(FileName, lists:flatten(io_lib:fwrite("~p. ", [Term]))). %% @doc Finds files and directories that match the regexp supplied in %% the TargetPattern regexp. -spec find(FromDir::file:name(), TargetPattern::string()) -> [file:name()]. find([], _) -> []; find(FromDir, TargetPattern) -> case is_dir(FromDir) of false -> case re:run(FromDir, TargetPattern) of {match, _} -> [FromDir]; _ -> [] end; true -> FoundDir = case re:run(FromDir, TargetPattern) of {match, _} -> [FromDir]; _ -> [] end, List = find_in_subdirs(FromDir, TargetPattern), FoundDir ++ List end. %%%=================================================================== %%% Internal Functions %%%=================================================================== -spec find_in_subdirs(file:name(), string()) -> [file:name()]. find_in_subdirs(FromDir, TargetPattern) -> lists:foldl(fun(CheckFromDir, Acc) when CheckFromDir == FromDir -> Acc; (ChildFromDir, Acc) -> case find(ChildFromDir, TargetPattern) of [] -> Acc; Res -> Res ++ Acc end end, [], sub_files(FromDir)). -spec remove_recursive(file:name(), Options::list()) -> ok | {error, Reason::term()}. remove_recursive(Path, Options) -> case is_dir(Path) of false -> file:delete(Path); true -> lists:foreach(fun(ChildPath) -> remove_recursive(ChildPath, Options) end, sub_files(Path)), file:del_dir(Path) end. -spec tmp() -> file:name(). tmp() -> case os:type() of {win32, _} -> case os:getenv("TEMP") of false -> "./tmp"; Val -> Val end; _ -> case os:getenv("TMPDIR") of false -> "/tmp"; Val -> Val end end. %% Copy the subfiles of the From directory to the to directory. -spec copy_subfiles(file:name(), file:name(), [option()]) -> {error, Reason::term()} | ok. copy_subfiles(From, To, Options) -> Fun = fun(ChildFrom) -> ChildTo = filename:join([To, filename:basename(ChildFrom)]), copy(ChildFrom, ChildTo, Options) end, lists:foreach(Fun, sub_files(From)). -spec make_dir_if_dir(file:name()) -> ok | {error, Reason::term()}. make_dir_if_dir(File) -> case is_dir(File) of true -> ok; false -> mkdir_path(File) end. %% @doc convert a list of integers into hex. -spec hex(string() | non_neg_integer()) -> string(). hex(L) when is_list (L) -> lists:flatten([hex(I) || I <- L]); hex(I) when I > 16#f -> [hex0((I band 16#f0) bsr 4), hex0((I band 16#0f))]; hex(I) -> [$0, hex0(I)]. hex0(10) -> $a; hex0(11) -> $b; hex0(12) -> $c; hex0(13) -> $d; hex0(14) -> $e; hex0(15) -> $f; hex0(I) -> $0 + I. sub_files(From) -> {ok, SubFiles} = file:list_dir(From), [filename:join(From, SubFile) || SubFile <- SubFiles].