[erlang-patches] exporting a new function in prim_file.erl
Filipe David Manana
Wed Apr 21 19:27:55 CEST 2010
Found the solution. Just need to execute:
after doing make, and before make install
On Wed, Apr 21, 2010 at 5:43 PM, Filipe David Manana <>wrote:
> Ups, misspelled it.
> I do have it in an exports declaration (copy paste from my prim_file.erl) :
> %%% Interface towards a single file's contents. Uses ?FD_DRV.
> %% Generic file contents operations
> -export([open/2, close/1, my_func/1, sync/1, position/2, truncate/1,
> write/2, pwrite/2, pwrite/3, read/2, read_line/1, pread/2, pread/3,
> This is why I am finding it very weird.
> In the shell:
> 5> lists:member("/opt/dev-otp/lib/erlang/lib/kernel-2.13.5/ebin",
> 6> code:which(prim_file).
> 7> prim_file:
> altname/1 altname/2 close/1
> copy/3 del_dir/1 del_dir/2
> delete/1 delete/2 get_cwd/0
> get_cwd/1 get_cwd/2 ipread_s32bu_p32bu/3
> list_dir/1 list_dir/2 make_dir/1
> make_dir/2 make_link/2 make_link/3
> make_symlink/2 make_symlink/3 module_info/0
> module_info/1 open/1 open/2
> open/3 open_int/4 open_mode/1
> open_mode/4 position/2 pread/2
> pread/3 pwrite/2 pwrite/3
> read/2 read_file/1 read_file/2
> read_file_info/1 read_file_info/2 read_line/1
> read_link/1 read_link/2 read_link_info/1
> read_link_info/2 rename/2 rename/3
> set_cwd/1 set_cwd/2 start/0
> stop/1 sync/1 truncate/1
> write/2 write_file/2 write_file_info/2
> Are preloaded modules different from regular modules?
> On Wed, Apr 21, 2010 at 5:26 PM, Robert Virding <>wrote:
>> Hi Filipe,
>> On 21 April 2010 18:18, Filipe David Manana <> wrote:
>> > Hello,
>> > I'm trying to add a new function to prim_file.erl that will be called by
>> > file_io_server.erl. Therefore I export it in the first export macro.
>> > This new function happens to have exactly the same interface (arity and
>> > type, return values) as prim_file:sync/1, so I copied the sync function
>> > clause, renamed it, and added the corresponding export.
>> > After building and installing OTP, I get an error when calling
>> > file:my_func/1:
>> > =ERROR REPORT==== 21-Apr-2010::16:30:53 ===
>> > Error in process <0.35.0> with exit value:
>> > file:my_func/1 just calls file_io_server:my_func/1 wich in turn calls
>> > prim_file:my_func/1.
>> > It seems that prim_file is not exporting my_func. Yet I have an
>> > "-define([... sync/1 my_func/1 ...])."
>> This, -define, is used to define macros, not for exporting functions
>> from a module. It should be:
>> -export(([... sync/1 my_func/1 ...]).
>> There is an export declaration already which exports the old
>> functions. It is perfectly ok to have many export declaration, I use
>> that to cluster various "classes" of exported functions.
> Filipe David Manana,
> "Reasonable men adapt themselves to the world.
> Unreasonable men adapt the world to themselves.
> That's why all progress depends on unreasonable men."
Filipe David Manana,
"Reasonable men adapt themselves to the world.
Unreasonable men adapt the world to themselves.
That's why all progress depends on unreasonable men."
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