------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME COMPONENTS -- -- -- -- S Y S T E M . F I L E _ I O -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2022, 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 -- -- . -- -- -- -- 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;