1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- G N A T . I O _ A U X -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1995-2010, AdaCore -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32with Interfaces.C_Streams; use Interfaces.C_Streams; 33 34package body GNAT.IO_Aux is 35 36 Buflen : constant := 2000; 37 -- Buffer length. Works for any non-zero value, larger values take 38 -- more stack space, smaller values require more recursion. 39 40 ----------------- 41 -- File_Exists -- 42 ----------------- 43 44 function File_Exists (Name : String) return Boolean 45 is 46 Namestr : aliased String (1 .. Name'Length + 1); 47 -- Name as given with ASCII.NUL appended 48 49 begin 50 Namestr (1 .. Name'Length) := Name; 51 Namestr (Name'Length + 1) := ASCII.NUL; 52 return file_exists (Namestr'Address) /= 0; 53 end File_Exists; 54 55 -------------- 56 -- Get_Line -- 57 -------------- 58 59 -- Current_Input case 60 61 function Get_Line return String is 62 Buffer : String (1 .. Buflen); 63 -- Buffer to read in chunks of remaining line. Will work with any 64 -- size buffer. We choose a length so that most of the time no 65 -- recursion will be required. 66 67 Last : Natural; 68 69 begin 70 Ada.Text_IO.Get_Line (Buffer, Last); 71 72 -- If the buffer is not full, then we are all done 73 74 if Last < Buffer'Last then 75 return Buffer (1 .. Last); 76 77 -- Otherwise, we still have characters left on the line. Note that 78 -- as specified by (RM A.10.7(19)) the end of line is not skipped 79 -- in this case, even if we are right at it now. 80 81 else 82 return Buffer & GNAT.IO_Aux.Get_Line; 83 end if; 84 end Get_Line; 85 86 -- Case of reading from a specified file. Note that we could certainly 87 -- share code between these two versions, but these are very short 88 -- routines, and we may as well aim for maximum speed, cutting out an 89 -- intermediate call (calls returning string may be somewhat slow) 90 91 function Get_Line (File : Ada.Text_IO.File_Type) return String is 92 Buffer : String (1 .. Buflen); 93 Last : Natural; 94 95 begin 96 Ada.Text_IO.Get_Line (File, Buffer, Last); 97 98 if Last < Buffer'Last then 99 return Buffer (1 .. Last); 100 else 101 return Buffer & Get_Line (File); 102 end if; 103 end Get_Line; 104 105end GNAT.IO_Aux; 106