How may we do case-insensitive file-searches in Erlang/Elixir?

Questions / Help
,
1

Is there a way to do case-insensitive file-searches in Elixir/Erlang?

Matching is case-sensitive, for example, “a” does not match “A”. (Erlang -- filelib)

does not handle this completely.

2

You could always alternate the characters, so if searching for "blah.txt" and you want it to find any file regardless of case that matches then you could instead search for "[bB][lL][aA][hH].[tT][xX][tT]" or so, which is easily generateable.

Or you could just get all the files in the path and Enum.filter them out directly with a case insensitive regex or so.

/me thinks case-insensitive filenames is Not a good thing regardless

3

What happens when you are searching user created paths?

"DFR 200" or "Dfr 200" or "dfr 200"

iex(11)> fp = root <> "\\**DFR 200**\\20170101.{xls,xlsx}"
"C:\\Clients\\Pensure\\RECENT RMAS\\source files\\**DFR 200**\\20170101.{xls,xlsx}"
iex(12)> Path.wildcard fp                                 
["c:/Clients/Pensure/RECENT RMAS/source files/DFR 200/20170101.xlsx"]
iex(13)> fp = root <> "\\**dfr 200**\\20170101.{xls,xlsx}"
"C:\\Clients\\Pensure\\RECENT RMAS\\source files\\**dfr 200**\\20170101.{xls,xlsx}"
iex(14)> Path.wildcard fp                                 
[]
4

Not sure what you are asking? Also be careful about passing anything to the filesystem, even as a path, from user input, sanitize your inputs.

5

Got a very nice solution here:

defmodule A do
  def case_insensitive_glob(glob) do
    Regex.replace(~r/[a-zA-Z]/, glob, fn letter ->
      "[#{String.downcase(letter)}#{String.upcase(letter)}]"
    end)
  end
end

glob = A.case_insensitive_glob("**/*reAdmE.*") |> IO.inspect
Path.wildcard(glob) |> IO.inspect
6

Yep, that is precisely the kind of helper that would work then. :slight_smile:

7

This could be useful to have:

Path.wildcard("my path", [:case_insensitive])

8

I’m unsure how useful that would be (I’ve never needed a case insensitive path search in 30 years, seems very odd…), but you could always submit a PR to Elixir and see if it gets in. :slight_smile:

1 Like
9

mainly on windows