------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME COMPONENTS -- -- -- -- S Y S T E M . F I L E _ I O -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2004, 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. -- -- 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 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 : in 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, but otherwise is not used by this or any other -- routine in this unit (except Form which retrieves the original value) -- -- Amethod indicates the access method -- -- D = Direct_IO -- Q = Sequential_IO -- S = Stream_IO -- T = Text_IO -- W = 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 : in out 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 to null. procedure Delete (File : in out FCB.AFCB_Ptr); -- The indicated file is unlinked procedure Reset (File : in out FCB.AFCB_Ptr; Mode : in FCB.File_Mode); -- The file is reset, and the mode changed as indicated. procedure Reset (File : in out FCB.AFCB_Ptr); -- The files is reset, and the mode is unchanged function Mode (File : in FCB.AFCB_Ptr) return FCB.File_Mode; -- Returns the mode as supplied by create, open or reset function Name (File : in 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 : in 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 : in 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 spcial 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_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 ensure 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 : in 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;