106 lines
4.4 KiB
Ada
106 lines
4.4 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME COMPONENTS --
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-- --
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-- G N A T . I O _ A U X --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1995-2010, AdaCore --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Interfaces.C_Streams; use Interfaces.C_Streams;
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package body GNAT.IO_Aux is
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Buflen : constant := 2000;
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-- Buffer length. Works for any non-zero value, larger values take
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-- more stack space, smaller values require more recursion.
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-----------------
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-- File_Exists --
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-----------------
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function File_Exists (Name : String) return Boolean
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is
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Namestr : aliased String (1 .. Name'Length + 1);
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-- Name as given with ASCII.NUL appended
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begin
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Namestr (1 .. Name'Length) := Name;
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Namestr (Name'Length + 1) := ASCII.NUL;
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return file_exists (Namestr'Address) /= 0;
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end File_Exists;
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--------------
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-- Get_Line --
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--------------
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-- Current_Input case
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function Get_Line return String is
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Buffer : String (1 .. Buflen);
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-- Buffer to read in chunks of remaining line. Will work with any
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-- size buffer. We choose a length so that most of the time no
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-- recursion will be required.
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Last : Natural;
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begin
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Ada.Text_IO.Get_Line (Buffer, Last);
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-- If the buffer is not full, then we are all done
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if Last < Buffer'Last then
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return Buffer (1 .. Last);
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-- Otherwise, we still have characters left on the line. Note that
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-- as specified by (RM A.10.7(19)) the end of line is not skipped
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-- in this case, even if we are right at it now.
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else
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return Buffer & GNAT.IO_Aux.Get_Line;
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end if;
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end Get_Line;
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-- Case of reading from a specified file. Note that we could certainly
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-- share code between these two versions, but these are very short
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-- routines, and we may as well aim for maximum speed, cutting out an
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-- intermediate call (calls returning string may be somewhat slow)
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function Get_Line (File : Ada.Text_IO.File_Type) return String is
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Buffer : String (1 .. Buflen);
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Last : Natural;
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begin
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Ada.Text_IO.Get_Line (File, Buffer, Last);
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if Last < Buffer'Last then
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return Buffer (1 .. Last);
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else
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return Buffer & Get_Line (File);
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end if;
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end Get_Line;
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end GNAT.IO_Aux;
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