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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . F I L E _ I O --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2018, 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package provides support for the routines described in (RM A.8.2)
-- which are common to Text_IO, Direct_IO, Sequential_IO and Stream_IO.
with Interfaces.C_Streams;
with System.File_Control_Block;
package System.File_IO is
pragma Preelaborate;
package FCB renames System.File_Control_Block;
package ICS renames Interfaces.C_Streams;
---------------------
-- File Management --
---------------------
procedure Open
(File_Ptr : in out FCB.AFCB_Ptr;
Dummy_FCB : FCB.AFCB'Class;
Mode : FCB.File_Mode;
Name : String;
Form : String;
Amethod : Character;
Creat : Boolean;
Text : Boolean;
C_Stream : ICS.FILEs := ICS.NULL_Stream);
-- This routine is used for both Open and Create calls:
--
-- File_Ptr is the file type, which must be null on entry
-- (i.e. the file must be closed before the call).
--
-- Dummy_FCB is a default initialized file control block of appropriate
-- type. Note that the tag of this record indicates the type and length
-- of the control block. This control block is used only for the purpose
-- of providing the controlling argument for calling the write version
-- of Allocate_AFCB. It has no other purpose, and its fields are never
-- read or written.
--
-- Mode is the required mode
--
-- Name is the file name, with a null string indicating that a temporary
-- file is to be created (only permitted in create mode, not open mode).
--
-- Creat is True for a create call, and false for an open call
--
-- Text is set True to open the file in text mode (w+t or r+t) instead
-- of the usual binary mode open (w+b or r+b).
--
-- Form is the form string given in the open or create call, this is
-- stored in the AFCB.
--
-- Amethod indicates the access method:
--
-- D = Direct_IO
-- Q = Sequential_IO
-- S = Stream_IO
-- T = Text_IO
-- W = Wide_Text_IO
-- ??? Wide_Wide_Text_IO ???
--
-- C_Stream is left at its default value for the normal case of an
-- Open or Create call as defined in the RM. The only time this is
-- non-null is for the Open call from Ada.xxx_IO.C_Streams.Open.
--
-- On return, if the open/create succeeds, then the fields of File are
-- filled in, and this value is copied to the heap. File_Ptr points to
-- this allocated file control block. If the open/create fails, then the
-- fields of File are undefined, and File_Ptr is unchanged.
procedure Close (File_Ptr : access FCB.AFCB_Ptr);
-- The file is closed, all storage associated with it is released, and
-- File is set to null. Note that this routine calls AFCB_Close to perform
-- any specialized close actions, then closes the file at the system level,
-- then frees the mode and form strings, and finally calls AFCB_Free to
-- free the file control block itself, setting File.all to null. Note that
-- for this assignment to be done in all cases, including those where
-- an exception is raised, we can't use an IN OUT parameter (which would
-- not be copied back in case of abnormal return).
procedure Delete (File_Ptr : access FCB.AFCB_Ptr);
-- The indicated file is unlinked
procedure Reset (File_Ptr : access FCB.AFCB_Ptr; Mode : FCB.File_Mode);
-- The file is reset, and the mode changed as indicated
procedure Reset (File_Ptr : access FCB.AFCB_Ptr);
-- The files is reset, and the mode is unchanged
function Mode (File : FCB.AFCB_Ptr) return FCB.File_Mode;
-- Returns the mode as supplied by create, open or reset
function Name (File : FCB.AFCB_Ptr) return String;
-- Returns the file name as supplied by Open or Create. Raises Use_Error
-- if used with temporary files or standard files.
function Form (File : FCB.AFCB_Ptr) return String;
-- Returns the form as supplied by create, open or reset The string is
-- normalized to all lower case letters.
function Is_Open (File : FCB.AFCB_Ptr) return Boolean;
-- Determines if file is open or not
----------------------
-- Utility Routines --
----------------------
-- Some internal routines not defined in A.8.2. These are routines which
-- provide required common functionality shared by separate packages.
procedure Chain_File (File : FCB.AFCB_Ptr);
-- Used to chain the given file into the list of open files. Normally this
-- is done implicitly by Open. Chain_File is used for the special cases of
-- the system files defined by Text_IO (stdin, stdout, stderr) which are
-- not opened in the normal manner. Note that the caller is responsible
-- for task lock out to protect the global data structures if this is
-- necessary (it is needed for the calls from within this unit itself,
-- but not required for the calls from Text_IO and [Wide_]Wide_Text_IO
-- that are made during elaboration of the environment task).
procedure Check_File_Open (File : FCB.AFCB_Ptr);
-- If the current file is not open, then Status_Error is raised. Otherwise
-- control returns normally (with File pointing to the control block for
-- the open file.
procedure Check_Read_Status (File : FCB.AFCB_Ptr);
-- If the current file is not open, then Status_Error is raised. If the
-- file is open, then the mode is checked to make sure that reading is
-- permitted, and if not Mode_Error is raised, otherwise control returns
-- normally.
procedure Check_Write_Status (File : FCB.AFCB_Ptr);
-- If the current file is not open, then Status_Error is raised. If the
-- file is open, then the mode is checked to ensure that writing is
-- permitted, and if not Mode_Error is raised, otherwise control returns
-- normally.
function End_Of_File (File : FCB.AFCB_Ptr) return Boolean;
-- File must be opened in read mode. True is returned if the stream is
-- currently positioned at the end of file, otherwise False is returned.
-- The position of the stream is not affected.
procedure Flush (File : FCB.AFCB_Ptr);
-- Flushes the stream associated with the given file. The file must be open
-- and in write mode (if not, an appropriate exception is raised)
function Form_Boolean
(Form : String;
Keyword : String;
Default : Boolean) return Boolean;
-- Searches form string for an entry of the form keyword=xx where xx is
-- either yes/no or y/n. Returns True if yes or y is found, False if no or
-- n is found. If the keyword parameter is not found, returns the value
-- given as Default. May raise Use_Error if a form string syntax error is
-- detected. Keyword and Form must be in lower case.
function Form_Integer
(Form : String;
Keyword : String;
Default : Integer) return Integer;
-- Searches form string for an entry of the form Keyword=xx where xx is an
-- unsigned decimal integer in the range 0 to 999_999. Returns this integer
-- value if it is found. If the keyword parameter is not found, returns the
-- value given as Default. Raise Use_Error if a form string syntax error is
-- detected. Keyword and Form must be in lower case.
procedure Form_Parameter
(Form : String;
Keyword : String;
Start : out Natural;
Stop : out Natural);
-- Searches form string for an entry of the form Keyword=xx and if found
-- Sets Start and Stop to the first and last characters of xx. Keyword
-- and Form must be in lower case. If no entry matches, then Start and
-- Stop are set to zero on return. Use_Error is raised if a malformed
-- string is detected, but there is no guarantee of full syntax checking.
procedure Read_Buf
(File : FCB.AFCB_Ptr;
Buf : Address;
Siz : Interfaces.C_Streams.size_t);
-- Reads Siz bytes from File.Stream into Buf. The caller has checked
-- that the file is open in read mode. Raises an exception if Siz bytes
-- cannot be read (End_Error if no data was read, Data_Error if a partial
-- buffer was read, Device_Error if an error occurs).
procedure Read_Buf
(File : FCB.AFCB_Ptr;
Buf : Address;
Siz : Interfaces.C_Streams.size_t;
Count : out Interfaces.C_Streams.size_t);
-- Reads Siz bytes from File.Stream into Buf. The caller has checked that
-- the file is open in read mode. Device Error is raised if an error
-- occurs. Count is the actual number of bytes read, which may be less
-- than Siz if the end of file is encountered.
procedure Append_Set (File : FCB.AFCB_Ptr);
-- If the mode of the file is Append_File, then the file is positioned at
-- the end of file using fseek, otherwise this call has no effect.
procedure Write_Buf
(File : FCB.AFCB_Ptr;
Buf : Address;
Siz : Interfaces.C_Streams.size_t);
-- Writes size_t bytes to File.Stream from Buf. The caller has checked that
-- the file is open in write mode. Raises Device_Error if the complete
-- buffer cannot be written.
procedure Make_Unbuffered (File : FCB.AFCB_Ptr);
procedure Make_Line_Buffered
(File : FCB.AFCB_Ptr;
Line_Siz : Interfaces.C_Streams.size_t);
procedure Make_Buffered
(File : FCB.AFCB_Ptr;
Buf_Siz : Interfaces.C_Streams.size_t);
private
pragma Inline (Check_Read_Status);
pragma Inline (Check_Write_Status);
pragma Inline (Mode);
end System.File_IO;
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