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%% @author Bob Ippolito <bob@mochimedia.com>
%% @copyright 2010 Mochi Media, Inc.
%% @doc Create temporary files and directories. Requires crypto to be started.
-module(mochitemp).
-export([gettempdir/0]).
-export([mkdtemp/0, mkdtemp/3]).
-export([rmtempdir/1]).
%% -export([mkstemp/4]).
-define(SAFE_CHARS, {$a, $b, $c, $d, $e, $f, $g, $h, $i, $j, $k, $l, $m,
$n, $o, $p, $q, $r, $s, $t, $u, $v, $w, $x, $y, $z,
$A, $B, $C, $D, $E, $F, $G, $H, $I, $J, $K, $L, $M,
$N, $O, $P, $Q, $R, $S, $T, $U, $V, $W, $X, $Y, $Z,
$0, $1, $2, $3, $4, $5, $6, $7, $8, $9, $_}).
-define(TMP_MAX, 10000).
-include_lib("kernel/include/file.hrl").
%% TODO: An ugly wrapper over the mktemp tool with open_port and sadness?
%% We can't implement this race-free in Erlang without the ability
%% to issue O_CREAT|O_EXCL. I suppose we could hack something with
%% mkdtemp, del_dir, open.
%% mkstemp(Suffix, Prefix, Dir, Options) ->
%% ok.
rmtempdir(Dir) ->
case file:del_dir(Dir) of
{error, eexist} ->
ok = rmtempdirfiles(Dir),
ok = file:del_dir(Dir);
ok ->
ok
end.
rmtempdirfiles(Dir) ->
{ok, Files} = file:list_dir(Dir),
ok = rmtempdirfiles(Dir, Files).
rmtempdirfiles(_Dir, []) ->
ok;
rmtempdirfiles(Dir, [Basename | Rest]) ->
Path = filename:join([Dir, Basename]),
case filelib:is_dir(Path) of
true ->
ok = rmtempdir(Path);
false ->
ok = file:delete(Path)
end,
rmtempdirfiles(Dir, Rest).
mkdtemp() ->
mkdtemp("", "tmp", gettempdir()).
mkdtemp(Suffix, Prefix, Dir) ->
mkdtemp_n(rngpath_fun(Suffix, Prefix, Dir), ?TMP_MAX).
mkdtemp_n(RngPath, 1) ->
make_dir(RngPath());
mkdtemp_n(RngPath, N) ->
try make_dir(RngPath())
catch throw:{error, eexist} ->
mkdtemp_n(RngPath, N - 1)
end.
make_dir(Path) ->
case file:make_dir(Path) of
ok ->
ok;
E={error, eexist} ->
throw(E)
end,
%% Small window for a race condition here because dir is created 777
ok = file:write_file_info(Path, #file_info{mode=8#0700}),
Path.
rngpath_fun(Prefix, Suffix, Dir) ->
fun () ->
filename:join([Dir, Prefix ++ rngchars(6) ++ Suffix])
end.
rngchars(0) ->
"";
rngchars(N) ->
[rngchar() | rngchars(N - 1)].
rngchar() ->
rngchar(crypto:rand_uniform(0, tuple_size(?SAFE_CHARS))).
rngchar(C) ->
element(1 + C, ?SAFE_CHARS).
%% @spec gettempdir() -> string()
%% @doc Get a usable temporary directory using the first of these that is a directory:
%% $TMPDIR, $TMP, $TEMP, "/tmp", "/var/tmp", "/usr/tmp", ".".
gettempdir() ->
gettempdir(gettempdir_checks(), fun normalize_dir/1).
gettempdir_checks() ->
[{fun os:getenv/1, ["TMPDIR", "TMP", "TEMP"]},
{fun gettempdir_identity/1, ["/tmp", "/var/tmp", "/usr/tmp"]},
{fun gettempdir_cwd/1, [cwd]}].
gettempdir_identity(L) ->
L.
gettempdir_cwd(cwd) ->
{ok, L} = file:get_cwd(),
L.
gettempdir([{_F, []} | RestF], Normalize) ->
gettempdir(RestF, Normalize);
gettempdir([{F, [L | RestL]} | RestF], Normalize) ->
case Normalize(F(L)) of
false ->
gettempdir([{F, RestL} | RestF], Normalize);
Dir ->
Dir
end.
normalize_dir(False) when False =:= false orelse False =:= "" ->
%% Erlang doesn't have an unsetenv, wtf.
false;
normalize_dir(L) ->
Dir = filename:absname(L),
case filelib:is_dir(Dir) of
false ->
false;
true ->
Dir
end.
%%
%% Tests
%%
-ifdef(TEST).
-include_lib("eunit/include/eunit.hrl").
pushenv(L) ->
[{K, os:getenv(K)} || K <- L].
popenv(L) ->
F = fun ({K, false}) ->
%% Erlang doesn't have an unsetenv, wtf.
os:putenv(K, "");
({K, V}) ->
os:putenv(K, V)
end,
lists:foreach(F, L).
gettempdir_fallback_test() ->
?assertEqual(
"/",
gettempdir([{fun gettempdir_identity/1, ["/--not-here--/"]},
{fun gettempdir_identity/1, ["/"]}],
fun normalize_dir/1)),
?assertEqual(
"/",
%% simulate a true os:getenv unset env
gettempdir([{fun gettempdir_identity/1, [false]},
{fun gettempdir_identity/1, ["/"]}],
fun normalize_dir/1)),
ok.
gettempdir_identity_test() ->
?assertEqual(
"/",
gettempdir([{fun gettempdir_identity/1, ["/"]}], fun normalize_dir/1)),
ok.
gettempdir_cwd_test() ->
{ok, Cwd} = file:get_cwd(),
?assertEqual(
normalize_dir(Cwd),
gettempdir([{fun gettempdir_cwd/1, [cwd]}], fun normalize_dir/1)),
ok.
rngchars_test() ->
crypto:start(),
?assertEqual(
"",
rngchars(0)),
?assertEqual(
10,
length(rngchars(10))),
ok.
rngchar_test() ->
?assertEqual(
$a,
rngchar(0)),
?assertEqual(
$A,
rngchar(26)),
?assertEqual(
$_,
rngchar(62)),
ok.
mkdtemp_n_failonce_test() ->
crypto:start(),
D = mkdtemp(),
Path = filename:join([D, "testdir"]),
%% Toggle the existence of a dir so that it fails
%% the first time and succeeds the second.
F = fun () ->
case filelib:is_dir(Path) of
true ->
file:del_dir(Path);
false ->
file:make_dir(Path)
end,
Path
end,
try
%% Fails the first time
?assertThrow(
{error, eexist},
mkdtemp_n(F, 1)),
%% Reset state
file:del_dir(Path),
%% Succeeds the second time
?assertEqual(
Path,
mkdtemp_n(F, 2))
after rmtempdir(D)
end,
ok.
mkdtemp_n_fail_test() ->
{ok, Cwd} = file:get_cwd(),
?assertThrow(
{error, eexist},
mkdtemp_n(fun () -> Cwd end, 1)),
?assertThrow(
{error, eexist},
mkdtemp_n(fun () -> Cwd end, 2)),
ok.
make_dir_fail_test() ->
{ok, Cwd} = file:get_cwd(),
?assertThrow(
{error, eexist},
make_dir(Cwd)),
ok.
mkdtemp_test() ->
crypto:start(),
D = mkdtemp(),
?assertEqual(
true,
filelib:is_dir(D)),
?assertEqual(
ok,
file:del_dir(D)),
ok.
rmtempdir_test() ->
crypto:start(),
D1 = mkdtemp(),
?assertEqual(
true,
filelib:is_dir(D1)),
?assertEqual(
ok,
rmtempdir(D1)),
D2 = mkdtemp(),
?assertEqual(
true,
filelib:is_dir(D2)),
ok = file:write_file(filename:join([D2, "foo"]), <<"bytes">>),
D3 = mkdtemp("suffix", "prefix", D2),
?assertEqual(
true,
filelib:is_dir(D3)),
ok = file:write_file(filename:join([D3, "foo"]), <<"bytes">>),
?assertEqual(
ok,
rmtempdir(D2)),
?assertEqual(
{error, enoent},
file:consult(D3)),
?assertEqual(
{error, enoent},
file:consult(D2)),
ok.
gettempdir_env_test() ->
Env = pushenv(["TMPDIR", "TEMP", "TMP"]),
FalseEnv = [{"TMPDIR", false}, {"TEMP", false}, {"TMP", false}],
try
popenv(FalseEnv),
popenv([{"TMPDIR", "/"}]),
?assertEqual(
"/",
os:getenv("TMPDIR")),
?assertEqual(
"/",
gettempdir()),
{ok, Cwd} = file:get_cwd(),
popenv(FalseEnv),
popenv([{"TMP", Cwd}]),
?assertEqual(
normalize_dir(Cwd),
gettempdir())
after popenv(Env)
end,
ok.
-endif.
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