diff options
Diffstat (limited to 'lib/stdlib/src/filename.erl')
| -rw-r--r-- | lib/stdlib/src/filename.erl | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/lib/stdlib/src/filename.erl b/lib/stdlib/src/filename.erl index 2a2f25dcd2..b5df5c9d37 100644 --- a/lib/stdlib/src/filename.erl +++ b/lib/stdlib/src/filename.erl @@ -37,7 +37,8 @@ -export([absname/1, absname/2, absname_join/2, basename/1, basename/2, dirname/1, extension/1, join/1, join/2, pathtype/1, - rootname/1, rootname/2, split/1, flatten/1, nativename/1]). + rootname/1, rootname/2, split/1, flatten/1, nativename/1, + safe_relative_path/1]). -export([find_src/1, find_src/2]). % deprecated -export([basedir/2, basedir/3]). @@ -753,12 +754,46 @@ separators() -> _ -> {false, false} end. +-spec safe_relative_path(Filename) -> 'unsafe' | SafeFilename when + Filename :: file:name_all(), + SafeFilename :: file:name_all(). + +safe_relative_path(Path) -> + case pathtype(Path) of + relative -> + Cs0 = split(Path), + safe_relative_path_1(Cs0, []); + _ -> + unsafe + end. + +safe_relative_path_1(["."|T], Acc) -> + safe_relative_path_1(T, Acc); +safe_relative_path_1([<<".">>|T], Acc) -> + safe_relative_path_1(T, Acc); +safe_relative_path_1([".."|T], Acc) -> + climb(T, Acc); +safe_relative_path_1([<<"..">>|T], Acc) -> + climb(T, Acc); +safe_relative_path_1([H|T], Acc) -> + safe_relative_path_1(T, [H|Acc]); +safe_relative_path_1([], []) -> + []; +safe_relative_path_1([], Acc) -> + join(lists:reverse(Acc)). + +climb(_, []) -> + unsafe; +climb(T, [_|Acc]) -> + safe_relative_path_1(T, Acc). + %% NOTE: The find_src/1/2 functions are deprecated; they try to do too much %% at once and are not a good fit for this module. Parts of the code have %% been moved to filelib:find_file/2 instead. Only this part of this %% module is allowed to call the filelib module; such mutual dependency %% should otherwise be avoided! This code should eventually be removed. %% + %% find_src(Module) -- %% find_src(Module, Rules) -- %% |