Re: Atomic file creation

[vlc <just.another.spam.account@googlemail.com>]

I also tried something like this:

 1  Ada.Text_IO.Create (Handle, Out_File);
 2  declare
 3     Temp_File : String := Ada.Text_IO.Name (Handle);
 4  begin
 5     Ada.Text_IO.Close (Handle);
 6     Ada.Text_IO.Rename (Temp_File, "file");
 7     Ada.Text_IO.Put_Line ("Success");
 8  exception
 9     when Ada.IO_Exceptions.Use_Error =>
10        Ada.Text_IO.Put_Line ("Failure");
11     when others =>
12        raise;
13  end;

But Ada.Text_IO.Rename always raises Ada.IO_Exceptions.Use_Error, even
if the file does not exist. But if I replace line 1 with

 1  Ada.Text_IO.Create (Handle, Out_File, "my_temp_file");

it works. It seems that Ada.Text_IO.Rename cannot rename temporary
files for whatever reason.

Using Ada.Directories.Copy_File instead of Ada.Text_IO.Rename does not
help as Ada.Directories.Copy_File overwrites files without raising an
exception. Bad luck ...