Re: Fill string with multiple lines from standard_input

["Alexei Polkhanov" <alexp@ica.net>]

Did you consider using POSIX library like Florist ? Like this code I use in
order to read
configuration parameters:

----------------------------------------------------------------------------
----
    -- Read configuration parameters from file
    ------------------------------------------------------------------------
--------
    procedure Read_Configuration(File : in String; Options : in out
Service_Options)
    is
        ConfigFile         : POSIX.IO.File_Descriptor;
        ConfigPathname     : POSIX.Pathname :=
           POSIX.To_POSIX_String(File & ASCII.NUL);

        LineNum            : Integer := 0;
        Total              : POSIX.IO_Count := 0; -- total characters read
    begin

        declare

            Use  POSIX;

            Buffer          : POSIX.IO.IO_Buffer(1..Read_Block_Size); --
read buffer
            LineBuffer      : POSIX.IO.IO_Buffer(1..256); -- temporary
buffer to skim line
            Last            : POSIX.IO_Count; -- last character in read
buffer

            CopyFromPosition: Integer := 0;
            PasteAtPosition : Integer := 1;
            CharactersToCopy: Integer := 0;

            -- copy characters from read buffer into line buffer
            procedure AddCharactersToLine is
            begin
                LineBuffer(PasteAtPosition..(PasteAtPosition +
CharactersToCopy - 1 )) :=
                    Buffer(CopyFromPosition..(CopyFromPosition +
CharactersToCopy - 1 ));
            end AddCharactersToLine;

            ParamName : Token;
            ParamValue: Token;

        begin
            ConfigFile := POSIX.IO.Open(ConfigPathname, POSIX.IO.Read_Only);

            while true loop

                 POSIX.IO.Read(ConfigFile, Buffer, Last);

                 CopyFromPosition := 0;
                 CharactersToCopy := 0;

                 for BufferPos in 1..Last loop
                     if Buffer(Integer(BufferPos)) = LF then

                         if CharactersToCopy > 0 then
                             AddCharactersToLine;

                             declare
                                Line : String :=
POSIX.To_String(LineBuffer(LineBuffer'First..CharactersToCopy));
                             begin
                                Split(Line, ParamName, ParamValue);
                                UpdateValue(Line, ParamName, ParamValue);

                                -- if ParamName.exists and ParamValue.exists
then
                                --   Put_Line(Integer'Image(LineNum) & ": "
                                --      &
Line(ParamName.first..ParamName.last)
                                --      & " =[" &
Line(ParamValue.first..ParamValue.last) & "]");
                                -- else
                                --   null;
                                -- end if;

                             end;

                             CharactersToCopy := 0;
                             CopyFromPosition := 0;
                             PasteAtPosition := 1;

                         else
                             null;
                         end if;

                         LineNum := LineNum + 1;
                      else
                             if CopyFromPosition = 0 then
                                 CopyFromPosition := Integer(BufferPos);
                             else
                                 null;
                             end if;
                             CharactersToCopy := CharactersToCopy + 1;
                      end if;
                  end loop;

                  if CharactersToCopy > 0 then
                      AddCharactersToLine;
                      PasteAtPosition := CharactersToCopy;
                  else
                      null;
                  end if;

                  Total := Total + Last;

              end loop;

            exception
                -- when Ada.Io_Exceptions.End_Error =>
                --    POSIX.IO.Close(ConfigFile);
                when others =>
                    POSIX.IO.Close(ConfigFile);
        end;

        exception
            when others =>
                Put_Line("Exception rethrown");

    end Read_Configuration;


Cheers,

---
Alexei Polkhanov,
Sr. Software Engineer,
Incognito Software Inc,
Vancouver, Canada

"Vincent Smeets" <No@Spam.org> wrote in message
news:ajebhb$ndl$01$1@news.t-online.com...
> Hallo,
>
> How can I fill a string with multiple lines from the standard_input? I
want
> to have all the characters read from the input till a end of file in a
> string.
>
> In C I can do it like this:
>     char buffer[1024];
>     ssize_t length;
>
>     length = read (1, buffer, sizeof (buffer));
>     if (length < 0) {
>         perror ("read");
>         exit (1);
>     }
>
> I can do it with Get_Immediate:
>     Buffer : String (1 .. 1024);
>     Length : Natural;
>
>     Length := 0;
>     while not Ent_Of_File and Length < Buffer'Last loop
>         Length := Length + 1;
>         Get_Immediate (Buffer (Length));
>     end loop;
> This works but is very slow with GNAT 3.13p on Windows 2000.
>
> I haven't tried sequential IO, but that is also character by character. I
> want something to read a buffer at once. I have been thinking about using
> streams. Something like:
>     Buffer : String (1 .. 1024);
>
>     String'Read (
>         Text_IO.Text_Streams.Stream (Text_IO.Standard_Input),
>         Buffer);
> But here I don't know how much of the Buffer has been filled.
>
> The last non portable design is to use a pragma import for the C "read"
> function. It will work but I don't like it because it isn't portable.
>
> Is the a nice Ada95 way to do this?
>
>