%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(file).
%% Interface module for the file server and the file io servers.
%%% External exports
-export([format_error/1]).
%% File system and metadata.
-export([get_cwd/0, get_cwd/1, set_cwd/1, delete/1, rename/2,
make_dir/1, del_dir/1, list_dir/1,
read_file_info/1, write_file_info/2,
altname/1,
read_link_info/1, read_link/1,
make_link/2, make_symlink/2,
read_file/1, write_file/2, write_file/3]).
%% Specialized
-export([ipread_s32bu_p32bu/3]).
%% Generic file contents.
-export([open/2, close/1, advise/4,
read/2, write/2,
pread/2, pread/3, pwrite/2, pwrite/3,
read_line/1,
position/2, truncate/1, datasync/1, sync/1,
copy/2, copy/3]).
%% High level operations
-export([consult/1, path_consult/2]).
-export([eval/1, eval/2, path_eval/2, path_eval/3, path_open/3]).
-export([script/1, script/2, path_script/2, path_script/3]).
-export([change_owner/2, change_owner/3, change_group/2,
change_mode/2, change_time/2, change_time/3]).
-export([pid2name/1]).
%%% Obsolete exported functions
-export([raw_read_file_info/1, raw_write_file_info/2]).
%% Internal export to prim_file and ram_file until they implement
%% an efficient copy themselves.
-export([copy_opened/3]).
-export([ipread_s32bu_p32bu_int/3]).
%% Types that can be used from other modules -- alphabetically ordered.
-export_type([date_time/0, fd/0, file_info/0, filename/0, io_device/0,
name/0, posix/0]).
%%% Includes and defines
-include("file.hrl").
-define(FILE_IO_SERVER_TABLE, file_io_servers).
-define(FILE_SERVER, file_server_2). % Registered name
-define(PRIM_FILE, prim_file). % Module
-define(RAM_FILE, ram_file). % Module
%% data types
-type filename() :: string() | binary().
-type file_info() :: #file_info{}.
-type fd() :: #file_descriptor{}.
-type io_device() :: pid() | fd().
-type location() :: integer() | {'bof', integer()} | {'cur', integer()}
| {'eof', integer()} | 'bof' | 'cur' | 'eof'.
-type mode() :: 'read' | 'write' | 'append'
| 'exclusive' | 'raw' | 'binary'
| {'delayed_write', non_neg_integer(), non_neg_integer()}
| 'delayed_write' | {'read_ahead', pos_integer()}
| 'read_ahead' | 'compressed'
| {'encoding', unicode:encoding()}.
-type name() :: string() | atom() | [name()] | binary().
-type posix() :: 'eacces' | 'eagain' | 'ebadf' | 'ebusy' | 'edquot'
| 'eexist' | 'efault' | 'efbig' | 'eintr' | 'einval'
| 'eio' | 'eisdir' | 'eloop' | 'emfile' | 'emlink'
| 'enametoolong'
| 'enfile' | 'enodev' | 'enoent' | 'enomem' | 'enospc'
| 'enotblk' | 'enotdir' | 'enotsup' | 'enxio' | 'eperm'
| 'epipe' | 'erofs' | 'espipe' | 'esrch' | 'estale'
| 'exdev'.
-type bindings() :: any().
-type date() :: {pos_integer(), pos_integer(), pos_integer()}.
-type time() :: {non_neg_integer(), non_neg_integer(), non_neg_integer()}.
-type date_time() :: {date(), time()}.
-type posix_file_advise() :: 'normal' | 'sequential' | 'random'
| 'no_reuse' | 'will_need' | 'dont_need'.
%%%-----------------------------------------------------------------
%%% General functions
-spec format_error(Reason :: posix() | {integer(), atom(), any()}) ->
string().
format_error({_Line, ?MODULE, undefined_script}) ->
"no value returned from script";
format_error({Line, ?MODULE, {Class, Reason, Stacktrace}}) ->
io_lib:format("~w: evaluation failed with reason ~w:~w and stacktrace ~w",
[Line, Class, Reason, Stacktrace]);
format_error({Line, ?MODULE, {Reason, Stacktrace}}) ->
io_lib:format("~w: evaluation failed with reason ~w and stacktrace ~w",
[Line, Reason, Stacktrace]);
format_error({Line, Mod, Reason}) ->
io_lib:format("~w: ~s", [Line, Mod:format_error(Reason)]);
format_error(badarg) ->
"bad argument";
format_error(system_limit) ->
"a system limit was hit, probably not enough ports";
format_error(terminated) ->
"the file server process is terminated";
format_error(ErrorId) ->
erl_posix_msg:message(ErrorId).
-spec pid2name(Pid :: pid()) -> {'ok', filename()} | 'undefined'.
pid2name(Pid) when is_pid(Pid) ->
case whereis(?FILE_SERVER) of
undefined ->
undefined;
_ ->
case ets:lookup(?FILE_IO_SERVER_TABLE, Pid) of
[{_, Name} | _] ->
{ok, Name};
_ ->
undefined
end
end.
%%%-----------------------------------------------------------------
%%% File server functions.
%%% Functions that do not operate on a single open file.
%%% Stateless.
-spec get_cwd() -> {'ok', filename()} | {'error', posix()}.
get_cwd() ->
call(get_cwd, []).
-spec get_cwd(Drive :: string()) -> {'ok', filename()} | {'error', posix()}.
get_cwd(Drive) ->
check_and_call(get_cwd, [file_name(Drive)]).
-spec set_cwd(Dirname :: name()) -> 'ok' | {'error', posix()}.
set_cwd(Dirname) ->
check_and_call(set_cwd, [file_name(Dirname)]).
-spec delete(Name :: name()) -> 'ok' | {'error', posix()}.
delete(Name) ->
check_and_call(delete, [file_name(Name)]).
-spec rename(From :: name(), To :: name()) -> 'ok' | {'error', posix()}.
rename(From, To) ->
check_and_call(rename, [file_name(From), file_name(To)]).
-spec make_dir(Name :: name()) -> 'ok' | {'error', posix()}.
make_dir(Name) ->
check_and_call(make_dir, [file_name(Name)]).
-spec del_dir(Name :: name()) -> 'ok' | {'error', posix()}.
del_dir(Name) ->
check_and_call(del_dir, [file_name(Name)]).
-spec read_file_info(Name :: name()) -> {'ok', file_info()} | {'error', posix()}.
read_file_info(Name) ->
check_and_call(read_file_info, [file_name(Name)]).
-spec altname(Name :: name()) -> any().
altname(Name) ->
check_and_call(altname, [file_name(Name)]).
-spec read_link_info(Name :: name()) -> {'ok', file_info()} | {'error', posix()}.
read_link_info(Name) ->
check_and_call(read_link_info, [file_name(Name)]).
-spec read_link(Name :: name()) -> {'ok', filename()} | {'error', posix()}.
read_link(Name) ->
check_and_call(read_link, [file_name(Name)]).
-spec write_file_info(Name :: name(), Info :: file_info()) ->
'ok' | {'error', posix()}.
write_file_info(Name, Info = #file_info{}) ->
check_and_call(write_file_info, [file_name(Name), Info]).
-spec list_dir(Name :: name()) -> {'ok', [filename()]} | {'error', posix()}.
list_dir(Name) ->
check_and_call(list_dir, [file_name(Name)]).
-spec read_file(Name :: name()) ->
{'ok', binary()} | {'error', posix() | 'terminated' | 'system_limit'}.
read_file(Name) ->
check_and_call(read_file, [file_name(Name)]).
-spec make_link(Old :: name(), New :: name()) -> 'ok' | {'error', posix()}.
make_link(Old, New) ->
check_and_call(make_link, [file_name(Old), file_name(New)]).
-spec make_symlink(Old :: name(), New :: name()) -> 'ok' | {'error', posix()}.
make_symlink(Old, New) ->
check_and_call(make_symlink, [file_name(Old), file_name(New)]).
-spec write_file(Name :: name(), Bin :: iodata()) ->
'ok' | {'error', posix() | 'terminated' | 'system_limit'}.
write_file(Name, Bin) ->
check_and_call(write_file, [file_name(Name), make_binary(Bin)]).
%% This whole operation should be moved to the file_server and prim_file
%% when it is time to change file server protocol again.
%% Meanwhile, it is implemented here, slightly less efficient.
-spec write_file(Name :: name(), Bin :: binary(), Modes :: [mode()]) ->
'ok' | {'error', posix()}.
write_file(Name, Bin, ModeList) when is_list(ModeList) ->
case make_binary(Bin) of
B when is_binary(B) ->
case open(Name, [binary, write |
lists:delete(binary,
lists:delete(write, ModeList))]) of
{ok, Handle} ->
case write(Handle, B) of
ok ->
close(Handle);
E1 ->
close(Handle),
E1
end;
E2 ->
E2
end;
E3 ->
E3
end.
%% Obsolete, undocumented, local node only, don't use!.
%% XXX to be removed.
raw_read_file_info(Name) ->
Args = [file_name(Name)],
case check_args(Args) of
ok ->
[FileName] = Args,
?PRIM_FILE:read_file_info(FileName);
Error ->
Error
end.
%% Obsolete, undocumented, local node only, don't use!.
%% XXX to be removed.
raw_write_file_info(Name, #file_info{} = Info) ->
Args = [file_name(Name)],
case check_args(Args) of
ok ->
[FileName] = Args,
?PRIM_FILE:write_file_info(FileName, Info);
Error ->
Error
end.
%%%-----------------------------------------------------------------
%%% File io server functions.
%%% They operate on a single open file.
%%% Stateful.
%% Contemporary mode specification - list of options
-spec open(Name :: name(), Modes :: [mode()]) ->
{'ok', io_device()} | {'error', posix() | 'system_limit'}.
open(Item, ModeList) when is_list(ModeList) ->
case lists:member(raw, ModeList) of
%% Raw file, use ?PRIM_FILE to handle this file
true ->
%% check if raw file mode is disabled
case catch application:get_env(kernel, raw_files) of
{ok,false} ->
open(Item, lists:delete(raw, ModeList));
_ -> % undefined | {ok,true}
Args = [file_name(Item) | ModeList],
case check_args(Args) of
ok ->
[FileName | _] = Args,
%% We rely on the returned Handle (in {ok, Handle})
%% being a pid() or a #file_descriptor{}
?PRIM_FILE:open(FileName, ModeList);
Error ->
Error
end
end;
false ->
case lists:member(ram, ModeList) of
%% RAM file, use ?RAM_FILE to handle this file
true ->
case check_args(ModeList) of
ok ->
?RAM_FILE:open(Item, ModeList);
Error ->
Error
end;
%% File server file
false ->
Args = [file_name(Item) | ModeList],
case check_args(Args) of
ok ->
[FileName | _] = Args,
call(open, [FileName, ModeList]);
Error ->
Error
end
end
end;
%% Old obsolete mode specification in atom or 2-tuple format
open(Item, Mode) ->
open(Item, mode_list(Mode)).
%%%-----------------------------------------------------------------
%%% The following interface functions operate on open files.
%%% The File argument must be either a Pid or a handle
%%% returned from ?PRIM_FILE:open.
-spec close(File :: io_device()) -> 'ok' | {'error', posix() | 'terminated'}.
close(File) when is_pid(File) ->
R = file_request(File, close),
case wait_file_reply(File, R) of
{error, terminated} ->
ok;
Other ->
Other
end;
%% unlink(File),
%% exit(File, close),
%% ok;
close(#file_descriptor{module = Module} = Handle) ->
Module:close(Handle);
close(_) ->
{error, badarg}.
-spec advise(File :: io_device(), Offset :: integer(),
Length :: integer(), Advise :: posix_file_advise()) ->
'ok' | {'error', posix()}.
advise(File, Offset, Length, Advise) when is_pid(File) ->
R = file_request(File, {advise, Offset, Length, Advise}),
wait_file_reply(File, R);
advise(#file_descriptor{module = Module} = Handle, Offset, Length, Advise) ->
Module:advise(Handle, Offset, Length, Advise);
advise(_, _, _, _) ->
{error, badarg}.
-spec read(File :: io_device() | atom(), Size :: non_neg_integer()) ->
'eof' | {'ok', [char()] | binary()} | {'error', posix()}.
read(File, Sz) when (is_pid(File) orelse is_atom(File)), is_integer(Sz), Sz >= 0 ->
case io:request(File, {get_chars, '', Sz}) of
Data when is_list(Data); is_binary(Data) ->
{ok, Data};
Other ->
Other
end;
read(#file_descriptor{module = Module} = Handle, Sz)
when is_integer(Sz), Sz >= 0 ->
Module:read(Handle, Sz);
read(_, _) ->
{error, badarg}.
-spec read_line(File :: io_device() | atom()) ->
'eof' | {'ok', [char()] | binary()} | {'error', posix()}.
read_line(File) when (is_pid(File) orelse is_atom(File)) ->
case io:request(File, {get_line, ''}) of
Data when is_list(Data); is_binary(Data) ->
{ok, Data};
Other ->
Other
end;
read_line(#file_descriptor{module = Module} = Handle) ->
Module:read_line(Handle);
read_line(_) ->
{error, badarg}.
-spec pread(File :: io_device(),
LocationNumbers :: [{location(), non_neg_integer()}]) ->
{'ok', [string() | binary() | 'eof']} | {'error', posix()}.
pread(File, L) when is_pid(File), is_list(L) ->
pread_int(File, L, []);
pread(#file_descriptor{module = Module} = Handle, L) when is_list(L) ->
Module:pread(Handle, L);
pread(_, _) ->
{error, badarg}.
pread_int(_File, [], R) ->
{ok, lists:reverse(R)};
pread_int(File, [{At, Sz} | T], R) when is_integer(Sz), Sz >= 0 ->
case pread(File, At, Sz) of
{ok, Data} ->
pread_int(File, T, [Data | R]);
eof ->
pread_int(File, T, [eof | R]);
{error, _} = Error ->
Error
end;
pread_int(_, _, _) ->
{error, badarg}.
-spec pread(File :: io_device(),
Location :: location(),
Size :: non_neg_integer()) ->
'eof' | {'ok', string() | binary()} | {'error', posix()}.
pread(File, At, Sz) when is_pid(File), is_integer(Sz), Sz >= 0 ->
R = file_request(File, {pread, At, Sz}),
wait_file_reply(File, R);
pread(#file_descriptor{module = Module} = Handle, Offs, Sz)
when is_integer(Sz), Sz >= 0 ->
Module:pread(Handle, Offs, Sz);
pread(_, _, _) ->
{error, badarg}.
-spec write(File :: io_device() | atom(), Byte :: iodata()) ->
'ok' | {'error', posix() | 'terminated'}.
write(File, Bytes) when (is_pid(File) orelse is_atom(File)) ->
case make_binary(Bytes) of
Bin when is_binary(Bin) ->
io:request(File, {put_chars,Bin});
Error ->
Error
end;
write(#file_descriptor{module = Module} = Handle, Bytes) ->
Module:write(Handle, Bytes);
write(_, _) ->
{error, badarg}.
-spec pwrite(File :: io_device(), L :: [{location(), iodata()}]) ->
'ok' | {'error', {non_neg_integer(), posix()}}.
pwrite(File, L) when is_pid(File), is_list(L) ->
pwrite_int(File, L, 0);
pwrite(#file_descriptor{module = Module} = Handle, L) when is_list(L) ->
Module:pwrite(Handle, L);
pwrite(_, _) ->
{error, badarg}.
pwrite_int(_File, [], _R) ->
ok;
pwrite_int(File, [{At, Bytes} | T], R) ->
case pwrite(File, At, Bytes) of
ok ->
pwrite_int(File, T, R+1);
{error, Reason} ->
{error, {R, Reason}}
end;
pwrite_int(_, _, _) ->
{error, badarg}.
-spec pwrite(File :: io_device(),
Location :: location(),
Bytes :: iodata()) ->
'ok' | {'error', posix()}.
pwrite(File, At, Bytes) when is_pid(File) ->
R = file_request(File, {pwrite, At, Bytes}),
wait_file_reply(File, R);
pwrite(#file_descriptor{module = Module} = Handle, Offs, Bytes) ->
Module:pwrite(Handle, Offs, Bytes);
pwrite(_, _, _) ->
{error, badarg}.
-spec datasync(File :: io_device()) -> 'ok' | {'error', posix()}.
datasync(File) when is_pid(File) ->
R = file_request(File, datasync),
wait_file_reply(File, R);
datasync(#file_descriptor{module = Module} = Handle) ->
Module:datasync(Handle);
datasync(_) ->
{error, badarg}.
-spec sync(File :: io_device()) -> 'ok' | {'error', posix()}.
sync(File) when is_pid(File) ->
R = file_request(File, sync),
wait_file_reply(File, R);
sync(#file_descriptor{module = Module} = Handle) ->
Module:sync(Handle);
sync(_) ->
{error, badarg}.
-spec position(File :: io_device(), Location :: location()) ->
{'ok',integer()} | {'error', posix()}.
position(File, At) when is_pid(File) ->
R = file_request(File, {position,At}),
wait_file_reply(File, R);
position(#file_descriptor{module = Module} = Handle, At) ->
Module:position(Handle, At);
position(_, _) ->
{error, badarg}.
-spec truncate(File :: io_device()) -> 'ok' | {'error', posix()}.
truncate(File) when is_pid(File) ->
R = file_request(File, truncate),
wait_file_reply(File, R);
truncate(#file_descriptor{module = Module} = Handle) ->
Module:truncate(Handle);
truncate(_) ->
{error, badarg}.
-spec copy(Source :: io_device() | name() | {name(), [mode()]},
Destination :: io_device() | name() | {name(), [mode()]}) ->
{'ok', non_neg_integer()} | {'error', posix()}.
copy(Source, Dest) ->
copy_int(Source, Dest, infinity).
-spec copy(Source :: io_device() | name() | {name(), [mode()]},
Destination :: io_device() | name() | {name(), [mode()]},
Length :: non_neg_integer() | 'infinity') ->
{'ok', non_neg_integer()} | {'error', posix()}.
copy(Source, Dest, Length)
when is_integer(Length), Length >= 0;
is_atom(Length) ->
copy_int(Source, Dest, Length);
copy(_, _, _) ->
{error, badarg}.
%% Here we know that Length is either an atom or an integer >= 0
%% (by the way, atoms > integers)
%%
%% Copy between open files.
copy_int(Source, Dest, Length)
when is_pid(Source), is_pid(Dest);
is_pid(Source), is_record(Dest, file_descriptor);
is_record(Source, file_descriptor), is_pid(Dest) ->
copy_opened_int(Source, Dest, Length, 0);
%% Copy between open raw files, both handled by the same module
copy_int(#file_descriptor{module = Module} = Source,
#file_descriptor{module = Module} = Dest,
Length) ->
Module:copy(Source, Dest, Length);
%% Copy between open raw files of different modules
copy_int(#file_descriptor{} = Source,
#file_descriptor{} = Dest, Length) ->
copy_opened_int(Source, Dest, Length, 0);
%% Copy between filenames, let the server do the copy
copy_int({SourceName, SourceOpts}, {DestName, DestOpts}, Length)
when is_list(SourceOpts), is_list(DestOpts) ->
check_and_call(copy,
[file_name(SourceName), SourceOpts,
file_name(DestName), DestOpts,
Length]);
%% Filename -> open file; must open Source and do client copy
copy_int({SourceName, SourceOpts}, Dest, Length)
when is_list(SourceOpts), is_pid(Dest);
is_list(SourceOpts), is_record(Dest, file_descriptor) ->
case file_name(SourceName) of
{error, _} = Error ->
Error;
Source ->
case open(Source, [read | SourceOpts]) of
{ok, Handle} ->
Result = copy_opened_int(Handle, Dest, Length, 0),
close(Handle),
Result;
{error, _} = Error ->
Error
end
end;
%% Open file -> filename; must open Dest and do client copy
copy_int(Source, {DestName, DestOpts}, Length)
when is_pid(Source), is_list(DestOpts);
is_record(Source, file_descriptor), is_list(DestOpts) ->
case file_name(DestName) of
{error, _} = Error ->
Error;
Dest ->
case open(Dest, [write | DestOpts]) of
{ok, Handle} ->
Result = copy_opened_int(Source, Handle, Length, 0),
close(Handle),
Result;
{error, _} = Error ->
Error
end
end;
%%
%% That was all combinations of {Name, Opts} tuples
%% and open files. At least one of Source and Dest has
%% to be a bare filename.
%%
%% If Source is not a bare filename; Dest must be
copy_int(Source, Dest, Length)
when is_pid(Source);
is_record(Source, file_descriptor) ->
copy_int(Source, {Dest, []}, Length);
copy_int({_SourceName, SourceOpts} = Source, Dest, Length)
when is_list(SourceOpts) ->
copy_int(Source, {Dest, []}, Length);
%% If Dest is not a bare filename; Source must be
copy_int(Source, Dest, Length)
when is_pid(Dest);
is_record(Dest, file_descriptor) ->
copy_int({Source, []}, Dest, Length);
copy_int(Source, {_DestName, DestOpts} = Dest, Length)
when is_list(DestOpts) ->
copy_int({Source, []}, Dest, Length);
%% Both must be bare filenames. If they are not,
%% the filename check in the copy operation will yell.
copy_int(Source, Dest, Length) ->
copy_int({Source, []}, {Dest, []}, Length).
copy_opened(Source, Dest, Length)
when is_integer(Length), Length >= 0;
is_atom(Length) ->
copy_opened_int(Source, Dest, Length);
copy_opened(_, _, _) ->
{error, badarg}.
%% Here we know that Length is either an atom or an integer >= 0
%% (by the way, atoms > integers)
copy_opened_int(Source, Dest, Length)
when is_pid(Source), is_pid(Dest) ->
copy_opened_int(Source, Dest, Length, 0);
copy_opened_int(Source, Dest, Length)
when is_pid(Source), is_record(Dest, file_descriptor) ->
copy_opened_int(Source, Dest, Length, 0);
copy_opened_int(Source, Dest, Length)
when is_record(Source, file_descriptor), is_pid(Dest) ->
copy_opened_int(Source, Dest, Length, 0);
copy_opened_int(Source, Dest, Length)
when is_record(Source, file_descriptor), is_record(Dest, file_descriptor) ->
copy_opened_int(Source, Dest, Length, 0);
copy_opened_int(_, _, _) ->
{error, badarg}.
%% Here we know that Source and Dest are handles to open files, Length is
%% as above, and Copied is an integer >= 0
%% Copy loop in client process
copy_opened_int(_, _, Length, Copied) when Length =< 0 -> % atom() > integer()
{ok, Copied};
copy_opened_int(Source, Dest, Length, Copied) ->
N = if Length > 65536 -> 65536; true -> Length end, % atom() > integer() !
case read(Source, N) of
{ok, Data} ->
M = if is_binary(Data) -> byte_size(Data);
is_list(Data) -> length(Data)
end,
case write(Dest, Data) of
ok ->
if M < N ->
%% Got less than asked for - must be end of file
{ok, Copied+M};
true ->
%% Decrement Length (might be an atom (infinity))
NewLength = if is_atom(Length) -> Length;
true -> Length-M
end,
copy_opened_int(Source, Dest, NewLength, Copied+M)
end;
{error, _} = Error ->
Error
end;
eof ->
{ok, Copied};
{error, _} = Error ->
Error
end.
%% Special indirect pread function. Introduced for Dets.
%% Reads a header from pos 'Pos', the header is first a size encoded as
%% 32 bit big endian unsigned and then a position also encoded as
%% 32 bit big endian. Finally it preads the data from that pos and size
%% in the file.
ipread_s32bu_p32bu(File, Pos, MaxSize) when is_pid(File) ->
ipread_s32bu_p32bu_int(File, Pos, MaxSize);
ipread_s32bu_p32bu(#file_descriptor{module = Module} = Handle, Pos, MaxSize) ->
Module:ipread_s32bu_p32bu(Handle, Pos, MaxSize);
ipread_s32bu_p32bu(_, _, _) ->
{error, badarg}.
ipread_s32bu_p32bu_int(File, Pos, Infinity) when is_atom(Infinity) ->
ipread_s32bu_p32bu_int(File, Pos, (1 bsl 31)-1);
ipread_s32bu_p32bu_int(File, Pos, MaxSize)
when is_integer(MaxSize), MaxSize >= 0 ->
if
MaxSize < (1 bsl 31) ->
case pread(File, Pos, 8) of
{ok, Header} ->
ipread_s32bu_p32bu_2(File, Header, MaxSize);
Error ->
Error
end;
true ->
{error, einval}
end;
ipread_s32bu_p32bu_int(_File, _Pos, _MaxSize) ->
{error, badarg}.
ipread_s32bu_p32bu_2(_File,
<<0:32/big-unsigned, Pos:32/big-unsigned>>,
_MaxSize) ->
{ok, {0, Pos, eof}};
ipread_s32bu_p32bu_2(File,
<<Size:32/big-unsigned, Pos:32/big-unsigned>>,
MaxSize)
when Size =< MaxSize ->
case pread(File, Pos, Size) of
{ok, Data} ->
{ok, {Size, Pos, Data}};
eof ->
{ok, {Size, Pos, eof}};
Error ->
Error
end;
ipread_s32bu_p32bu_2(_File,
<<_:8/binary>>,
_MaxSize) ->
eof;
ipread_s32bu_p32bu_2(_File,
<<_/binary>>,
_MaxSize) ->
eof;
ipread_s32bu_p32bu_2(File,
Header,
MaxSize) when is_list(Header) ->
ipread_s32bu_p32bu_2(File, list_to_binary(Header), MaxSize).
%%%-----------------------------------------------------------------
%%% The following functions, built upon the other interface functions,
%%% provide a higher-lever interface to files.
-spec consult(File :: name()) ->
{'ok', list()} | {'error', posix() | {integer(), atom(), any()}}.
consult(File) ->
case open(File, [read]) of
{ok, Fd} ->
R = consult_stream(Fd),
close(Fd),
R;
Error ->
Error
end.
-spec path_consult(Paths :: [name()], File :: name()) ->
{'ok', list(), filename()} | {'error', posix() | {integer(), atom(), any()}}.
path_consult(Path, File) ->
case path_open(Path, File, [read]) of
{ok, Fd, Full} ->
case consult_stream(Fd) of
{ok, List} ->
close(Fd),
{ok, List, Full};
E1 ->
close(Fd),
E1
end;
E2 ->
E2
end.
-spec eval(File :: name()) -> 'ok' | {'error', posix()}.
eval(File) ->
eval(File, erl_eval:new_bindings()).
-spec eval(File :: name(), Bindings :: bindings()) ->
'ok' | {'error', posix()}.
eval(File, Bs) ->
case open(File, [read]) of
{ok, Fd} ->
R = eval_stream(Fd, ignore, Bs),
close(Fd),
R;
Error ->
Error
end.
-spec path_eval(Paths :: [name()], File :: name()) ->
{'ok', filename()} | {'error', posix() | {integer(), atom(), any()}}.
path_eval(Path, File) ->
path_eval(Path, File, erl_eval:new_bindings()).
-spec path_eval(Paths :: [name()], File :: name(), Bindings :: bindings()) ->
{'ok', filename()} | {'error', posix() | {integer(), atom(), any()}}.
path_eval(Path, File, Bs) ->
case path_open(Path, File, [read]) of
{ok, Fd, Full} ->
case eval_stream(Fd, ignore, Bs) of
ok ->
close(Fd),
{ok, Full};
E1 ->
close(Fd),
E1
end;
E2 ->
E2
end.
-spec script(File :: name()) ->
{'ok', any()} | {'error', posix() | {integer(), atom(), any()}}.
script(File) ->
script(File, erl_eval:new_bindings()).
-spec script(File :: name(), Bindings :: bindings()) ->
{'ok', any()} | {'error', posix() | {integer(), atom(), any()}}.
script(File, Bs) ->
case open(File, [read]) of
{ok, Fd} ->
R = eval_stream(Fd, return, Bs),
close(Fd),
R;
Error ->
Error
end.
-spec path_script/2 :: (Paths :: [name()], File :: name()) ->
{'ok', term(), filename()} | {'error', posix() | {integer(), atom(), _}}.
path_script(Path, File) ->
path_script(Path, File, erl_eval:new_bindings()).
-spec path_script(Paths :: [name()],
File :: name(),
Bindings :: bindings()) ->
{'ok', term(), filename()} | {'error', posix() | {integer(), atom(), _}}.
path_script(Path, File, Bs) ->
case path_open(Path, File, [read]) of
{ok,Fd,Full} ->
case eval_stream(Fd, return, Bs) of
{ok,R} ->
close(Fd),
{ok, R, Full};
E1 ->
close(Fd),
E1
end;
E2 ->
E2
end.
%% path_open(Paths, Filename, Mode) ->
%% {ok,FileDescriptor,FullName}
%% {error,Reason}
%%
%% Searches the Paths for file Filename which can be opened with Mode.
%% The path list is ignored if Filename contains an absolute path.
-spec path_open(Paths :: [name()], Name :: name(), Modes :: [mode()]) ->
{'ok', io_device(), filename()} | {'error', posix()}.
path_open(PathList, Name, Mode) ->
case file_name(Name) of
{error, _} = Error ->
Error;
FileName ->
case filename:pathtype(FileName) of
relative ->
path_open_first(PathList, FileName, Mode, enoent);
_ ->
case open(Name, Mode) of
{ok, Fd} ->
{ok, Fd, Name};
Error ->
Error
end
end
end.
-spec change_mode(Name :: name(), Mode :: integer()) ->
'ok' | {'error', posix()}.
change_mode(Name, Mode)
when is_integer(Mode) ->
write_file_info(Name, #file_info{mode=Mode}).
-spec change_owner(Name :: name(), OwnerId :: integer()) ->
'ok' | {'error', posix()}.
change_owner(Name, OwnerId)
when is_integer(OwnerId) ->
write_file_info(Name, #file_info{uid=OwnerId}).
-spec change_owner(Name :: name(),
OwnerId :: integer(),
GroupId :: integer()) ->
'ok' | {'error', posix()}.
change_owner(Name, OwnerId, GroupId)
when is_integer(OwnerId), is_integer(GroupId) ->
write_file_info(Name, #file_info{uid=OwnerId, gid=GroupId}).
-spec change_group(Name :: name(), GroupId :: integer()) ->
'ok' | {'error', posix()}.
change_group(Name, GroupId)
when is_integer(GroupId) ->
write_file_info(Name, #file_info{gid=GroupId}).
-spec change_time(Name :: name(), Time :: date_time()) ->
'ok' | {'error', posix()}.
change_time(Name, Time)
when is_tuple(Time) ->
write_file_info(Name, #file_info{mtime=Time}).
-spec change_time(Name :: name(),
ATime :: date_time(),
MTime :: date_time()) ->
'ok' | {'error', posix()}.
change_time(Name, Atime, Mtime)
when is_tuple(Atime), is_tuple(Mtime) ->
write_file_info(Name, #file_info{atime=Atime, mtime=Mtime}).
%%%-----------------------------------------------------------------
%%% Helpers
consult_stream(Fd) ->
consult_stream(Fd, 1, []).
consult_stream(Fd, Line, Acc) ->
case io:read(Fd, '', Line) of
{ok,Term,EndLine} ->
consult_stream(Fd, EndLine, [Term|Acc]);
{error,Error,_Line} ->
{error,Error};
{eof,_Line} ->
{ok,lists:reverse(Acc)}
end.
eval_stream(Fd, Handling, Bs) ->
eval_stream(Fd, Handling, 1, undefined, [], Bs).
eval_stream(Fd, H, Line, Last, E, Bs) ->
eval_stream2(io:parse_erl_exprs(Fd, '', Line), Fd, H, Last, E, Bs).
eval_stream2({ok,Form,EndLine}, Fd, H, Last, E, Bs0) ->
try erl_eval:exprs(Form, Bs0) of
{value,V,Bs} ->
eval_stream(Fd, H, EndLine, {V}, E, Bs)
catch Class:Reason ->
Error = {EndLine,?MODULE,{Class,Reason,erlang:get_stacktrace()}},
eval_stream(Fd, H, EndLine, Last, [Error|E], Bs0)
end;
eval_stream2({error,What,EndLine}, Fd, H, Last, E, Bs) ->
eval_stream(Fd, H, EndLine, Last, [What | E], Bs);
eval_stream2({eof,EndLine}, _Fd, H, Last, E, _Bs) ->
case {H, Last, E} of
{return, {Val}, []} ->
{ok, Val};
{return, undefined, E} ->
{error, hd(lists:reverse(E, [{EndLine,?MODULE,undefined_script}]))};
{ignore, _, []} ->
ok;
{_, _, [_|_] = E} ->
{error, hd(lists:reverse(E))}
end.
path_open_first([Path|Rest], Name, Mode, LastError) ->
case file_name(Path) of
{error, _} = Error ->
Error;
FilePath ->
FileName = filename:join(FilePath, Name),
case open(FileName, Mode) of
{ok, Fd} ->
{ok, Fd, FileName};
{error, enoent} ->
path_open_first(Rest, Name, Mode, LastError);
Error ->
Error
end
end;
path_open_first([], _Name, _Mode, LastError) ->
{error, LastError}.
%%%-----------------------------------------------------------------
%%% Utility functions.
%% file_name(FileName)
%% Generates a flat file name from a deep list of atoms and
%% characters (integers).
file_name(N) when is_binary(N) ->
N;
file_name(N) ->
try
file_name_1(N,file:native_name_encoding())
catch Reason ->
{error, Reason}
end.
file_name_1([C|T],latin1) when is_integer(C), C < 256->
[C|file_name_1(T,latin1)];
file_name_1([C|T],utf8) when is_integer(C) ->
[C|file_name_1(T,utf8)];
file_name_1([H|T],E) ->
file_name_1(H,E) ++ file_name_1(T,E);
file_name_1([],_) ->
[];
file_name_1(N,_) when is_atom(N) ->
atom_to_list(N);
file_name_1(_,_) ->
throw(badarg).
make_binary(Bin) when is_binary(Bin) ->
Bin;
make_binary(List) ->
%% Convert the list to a binary in order to avoid copying a list
%% to the file server.
try
erlang:iolist_to_binary(List)
catch error:Reason ->
{error, Reason}
end.
mode_list(read) ->
[read];
mode_list(write) ->
[write];
mode_list(read_write) ->
[read, write];
mode_list({binary, Mode}) when is_atom(Mode) ->
[binary | mode_list(Mode)];
mode_list({character, Mode}) when is_atom(Mode) ->
mode_list(Mode);
mode_list(_) ->
[{error, badarg}].
%%-----------------------------------------------------------------
%% Functions for communicating with the file server
call(Command, Args) when is_list(Args) ->
gen_server:call(?FILE_SERVER, list_to_tuple([Command | Args]), infinity).
check_and_call(Command, Args) when is_list(Args) ->
case check_args(Args) of
ok ->
call(Command, Args);
Error ->
Error
end.
check_args([{error, _}=Error|_Rest]) ->
Error;
check_args([_Name|Rest]) ->
check_args(Rest);
check_args([]) ->
ok.
%%-----------------------------------------------------------------
%% Functions for communicating with a file io server.
%% The messages sent have the following formats:
%%
%% {file_request,From,ReplyAs,Request}
%% {file_reply,ReplyAs,Reply}
file_request(Io, Request) ->
R = erlang:monitor(process, Io),
Io ! {file_request,self(),Io,Request},
R.
wait_file_reply(From, Ref) ->
receive
{file_reply,From,Reply} ->
erlang:demonitor(Ref),
receive {'DOWN', Ref, _, _, _} -> ok after 0 -> ok end,
%% receive {'EXIT', From, _} -> ok after 0 -> ok end,
Reply;
{'DOWN', Ref, _, _, _} ->
%% receive {'EXIT', From, _} -> ok after 0 -> ok end,
{error, terminated}
end.
