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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- I N T E R F A C E S . C _ S T R E A M S --
-- --
-- B o d y --
-- --
-- $Revision: 1.1 $
-- --
-- Copyright (C) 1996-1999 Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- This is the Alpha/VMS version.
package body Interfaces.C_Streams is
------------
-- fread --
------------
function fread
(buffer : voids;
size : size_t;
count : size_t;
stream : FILEs)
return size_t
is
Get_Count : size_t := 0;
type Buffer_Type is array (size_t range 1 .. count,
size_t range 1 .. size) of Character;
type Buffer_Access is access Buffer_Type;
function To_BA is new Unchecked_Conversion (voids, Buffer_Access);
BA : Buffer_Access := To_BA (buffer);
Ch : int;
begin
-- This Fread goes with the Fwrite below.
-- The C library fread sometimes can't read fputc generated files.
for C in 1 .. count loop
for S in 1 .. size loop
Ch := fgetc (stream);
if Ch = EOF then
return 0;
end if;
BA.all (C, S) := Character'Val (Ch);
end loop;
Get_Count := Get_Count + 1;
end loop;
return Get_Count;
end fread;
------------
-- fread --
------------
function fread
(buffer : voids;
index : size_t;
size : size_t;
count : size_t;
stream : FILEs)
return size_t
is
Get_Count : size_t := 0;
type Buffer_Type is array (size_t range 1 .. count,
size_t range 1 .. size) of Character;
type Buffer_Access is access Buffer_Type;
function To_BA is new Unchecked_Conversion (voids, Buffer_Access);
BA : Buffer_Access := To_BA (buffer);
Ch : int;
begin
-- This Fread goes with the Fwrite below.
-- The C library fread sometimes can't read fputc generated files.
for C in 1 + index .. count + index loop
for S in 1 .. size loop
Ch := fgetc (stream);
if Ch = EOF then
return 0;
end if;
BA.all (C, S) := Character'Val (Ch);
end loop;
Get_Count := Get_Count + 1;
end loop;
return Get_Count;
end fread;
------------
-- fwrite --
------------
function fwrite
(buffer : voids;
size : size_t;
count : size_t;
stream : FILEs)
return size_t
is
Put_Count : size_t := 0;
type Buffer_Type is array (size_t range 1 .. count,
size_t range 1 .. size) of Character;
type Buffer_Access is access Buffer_Type;
function To_BA is new Unchecked_Conversion (voids, Buffer_Access);
BA : Buffer_Access := To_BA (buffer);
begin
-- Fwrite on VMS has the undesirable effect of always generating at
-- least one record of output per call, regardless of buffering. To
-- get around this, we do multiple fputc calls instead.
for C in 1 .. count loop
for S in 1 .. size loop
if fputc (Character'Pos (BA.all (C, S)), stream) = EOF then
exit;
end if;
end loop;
Put_Count := Put_Count + 1;
end loop;
return Put_Count;
end fwrite;
-------------
-- setvbuf --
-------------
function setvbuf
(stream : FILEs;
buffer : chars;
mode : int;
size : size_t)
return int
is
function C_setvbuf
(stream : FILEs;
buffer : chars;
mode : int;
size : size_t)
return int;
pragma Import (C, C_setvbuf, "setvbuf");
use type System.Address;
begin
-- In order for the above fwrite hack to work, we must always buffer
-- stdout and stderr. Is_regular_file on VMS cannot detect when
-- these are redirected to a file, so checking for that condition
-- doesn't help.
if mode = IONBF
and then (stream = stdout or else stream = stderr)
then
return C_setvbuf (stream, buffer, IOLBF, size);
else
return C_setvbuf (stream, buffer, mode, size);
end if;
end setvbuf;
end Interfaces.C_Streams;