1 defmodule Pleroma.MIME do
3 Returns the mime-type of a binary and optionally a normalized file-name. Requires at least (the first) 8 bytes.
5 @default "application/octet-stream"
7 @spec file_mime_type(String.t()) ::
8 {:ok, content_type :: String.t(), filename :: String.t()} | {:error, any()} | :error
9 def file_mime_type(path, filename) do
10 with {:ok, content_type} <- file_mime_type(path),
11 filename <- fix_extension(filename, content_type) do
12 {:ok, content_type, filename}
16 @spec file_mime_type(String.t()) :: {:ok, String.t()} | {:error, any()} | :error
17 def file_mime_type(filename) do
18 File.open(filename, [:read], fn f ->
19 check_mime_type(IO.binread(f, 8))
23 def bin_mime_type(binary, filename) do
24 with {:ok, content_type} <- bin_mime_type(binary),
25 filename <- fix_extension(filename, content_type) do
26 {:ok, content_type, filename}
30 @spec bin_mime_type(binary()) :: {:ok, String.t()} | :error
31 def bin_mime_type(<<head::binary-size(8), _::binary>>) do
32 {:ok, check_mime_type(head)}
35 def mime_type(<<_::binary>>), do: {:ok, @default}
37 def bin_mime_type(_), do: :error
39 defp fix_extension(filename, content_type) do
40 parts = String.split(filename, ".")
43 if length(parts) > 1 do
44 Enum.drop(parts, -1) |> Enum.join(".")
50 content_type == "application/octet-stream" ->
53 ext = List.first(MIME.extensions(content_type)) ->
54 new_filename <> "." <> ext
57 Enum.join([new_filename, String.split(content_type, "/") |> List.last()], ".")
61 defp check_mime_type(<<0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A>>) do
65 defp check_mime_type(<<0x47, 0x49, 0x46, 0x38, _, 0x61, _, _>>) do
69 defp check_mime_type(<<0xFF, 0xD8, 0xFF, _, _, _, _, _>>) do
73 defp check_mime_type(<<0x1A, 0x45, 0xDF, 0xA3, _, _, _, _>>) do
77 defp check_mime_type(<<0x00, 0x00, 0x00, _, 0x66, 0x74, 0x79, 0x70>>) do
81 defp check_mime_type(<<0x49, 0x44, 0x33, _, _, _, _, _>>) do
85 defp check_mime_type(<<255, 251, _, 68, 0, 0, 0, 0>>) do
89 defp check_mime_type(<<0x4F, 0x67, 0x67, 0x53, 0x00, 0x02, 0x00, 0x00>>) do
93 defp check_mime_type(<<0x52, 0x49, 0x46, 0x46, _, _, _, _>>) do
97 defp check_mime_type(_) do