Merge pull request #7220 from jdamanalo/kernel/file-read-file-raw

kernel/file: Add read_file/2 OTP-18589 OTP-18590
erlang · May 22, 2023 · 7df46d0 · 7df46d0
2 parents 4ab57f7 + 039a3bd
commit 7df46d0
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Showing 3 changed files with 52 additions and 5 deletions.
diff --git a/lib/kernel/doc/src/file.xml b/lib/kernel/doc/src/file.xml
@@ -1413,13 +1413,16 @@ f.txt:  {person, "kalle", 25}.
     </func>
     <func>
       <name name="read_file" arity="1" since=""/>
+      <name name="read_file" arity="2" since=""/>
       <fsummary>Read a file.</fsummary>
+      <type name="read_file_option"/>
       <desc>
         <p>Returns <c>{ok, <anno>Binary</anno>}</c>, where
           <c><anno>Binary</anno></c> is a binary
           data object that contains the contents of
           <c><anno>Filename</anno></c>, or
           <c>{error, <anno>Reason</anno>}</c> if an error occurs.</p>
+        <p>If the option <c>raw</c> is set, the file server is not called.</p>
         <p>Typical error reasons:</p>
         <taglist>
           <tag><c>enoent</c></tag>

diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl
@@ -36,7 +36,8 @@
 	 read_link_info/1, read_link_info/2,
 	 read_link/1, read_link_all/1,
 	 make_link/2, make_symlink/2,
-	 read_file/1, write_file/2, write_file/3]).
+	 read_file/1, read_file/2,
+	 write_file/2, write_file/3]).
 %% Specialized
 -export([ipread_s32bu_p32bu/3]).
 %% Generic file contents.
@@ -125,6 +126,7 @@
 -type posix_file_advise() :: 'normal' | 'sequential' | 'random'
                            | 'no_reuse' | 'will_need' | 'dont_need'.
 -type delete_option() :: 'raw'.
+-type read_file_option() :: 'raw'.
 -type sendfile_option() :: {chunk_size, non_neg_integer()}
 			 | {use_threads, boolean()}.
 -type file_info_option() :: {'time', 'local'} | {'time', 'universal'}
@@ -218,15 +220,14 @@ delete(Name) ->
       Reason :: posix() | badarg.
 
 delete(Name, Opts) when is_list(Opts) ->
-    Args = [file_name(Name), Opts],
-    case check_args(Args) of
+    FileName = file_name(Name),
+    case check_args(Opts) of
         ok ->
             case lists:member(raw, Opts) of
                 true ->
-                    [FileName|_] = Args,
                     ?PRIM_FILE:delete(FileName);
                 false ->
-                    call(delete, Args)
+                    call(delete, [FileName])
             end;
         Error ->
             Error
@@ -418,6 +419,26 @@ list_dir_all(Name) ->
 read_file(Name) ->
     check_and_call(read_file, [file_name(Name)]).
 
+-spec read_file(Filename, Opts) -> {ok, Binary} | {error, Reason} when
+      Filename :: name_all(),
+      Opts :: [read_file_option()],
+      Binary :: binary(),
+      Reason :: posix() | badarg | terminated | system_limit.
+
+read_file(Name, Opts) when is_list(Opts) ->
+    FileName = file_name(Name),
+    case check_args(Opts) of
+        ok ->
+            case lists:member(raw, Opts) of
+                true ->
+                    ?PRIM_FILE:read_file(FileName);
+                false ->
+                    call(read_file, [FileName])
+            end;
+        Error ->
+            Error
+    end.
+
 -spec make_link(Existing, New) -> ok | {error, Reason} when
       Existing :: name_all(),
       New :: name_all(),

diff --git a/lib/kernel/test/file_SUITE.erl b/lib/kernel/test/file_SUITE.erl
@@ -535,6 +535,9 @@ read_write_file(Config) when is_list(Config) ->
     {error, enoent} = ?FILE_MODULE:read_file(Name2),
     {error, enoent} = ?FILE_MODULE:read_file(""),
     {error, enoent} = ?FILE_MODULE:read_file(''),
+    {error, enoent} = ?FILE_MODULE:read_file(Name2, [raw]),
+    {error, enoent} = ?FILE_MODULE:read_file("", [raw]),
+    {error, enoent} = ?FILE_MODULE:read_file('', [raw]),
 
     %% Try writing to a bad filename
     {error, enoent} = do_read_write_file("", Bin2),
@@ -559,12 +562,15 @@ do_read_write_file(Name, Data) ->
 	ok ->
 	    BinData = iolist_to_binary(Data),
 	    {ok,BinData} = ?FILE_MODULE:read_file(Name),
+	    {ok,BinData} = ?FILE_MODULE:read_file(Name, [raw]),
 
 	    ok = ?FILE_MODULE:write_file(Name, Data, []),
 	    {ok,BinData} = ?FILE_MODULE:read_file(Name),
+	    {ok,BinData} = ?FILE_MODULE:read_file(Name, [raw]),
 
 	    ok = ?FILE_MODULE:write_file(Name, Data, [raw]),
 	    {ok,BinData} = ?FILE_MODULE:read_file(Name),
+	    {ok,BinData} = ?FILE_MODULE:read_file(Name, [raw]),
 
 	    ok;
 	{error,_}=Res ->
@@ -2333,6 +2339,23 @@ delete(Config) when is_list(Config) ->
     {error, _} = ?FILE_MODULE:open(Name2, read),
     %% Try deleting a nonexistent file with the raw option
     {error, enoent} = ?FILE_MODULE:delete(Name2, [raw]),
+
+    Name3 = filename:join(RootDir,
+                          atom_to_list(?MODULE)
+                          ++"_delete_3.fil"),
+    {ok, Fd5} = ?FILE_MODULE:open(Name3, write),
+    io:format(Fd5,"ok.\n",[]),
+    ok = ?FILE_MODULE:close(Fd5),
+    %% Check that the file is readable
+    {ok, Fd6} = ?FILE_MODULE:open(Name3, read),
+    ok = ?FILE_MODULE:close(Fd6),
+    %% Try deleting with no option, should be equivalent to delete/1
+    ok = ?FILE_MODULE:delete(Name3, []),
+    %% Check that the file is not readable anymore
+    {error, _} = ?FILE_MODULE:open(Name3, read),
+    %% Try deleting a nonexistent file with no option
+    {error, enoent} = ?FILE_MODULE:delete(Name3, []),
+
     [] = flush(),
     ok.