1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- G N A T . I O _ A U X --
9 -- Copyright (C) 1995-2005 AdaCore --
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 2, 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with Interfaces.C_Streams; use Interfaces.C_Streams;
36 package body GNAT.IO_Aux is
38 Buflen : constant := 2000;
39 -- Buffer length. Works for any non-zero value, larger values take
40 -- more stack space, smaller values require more recursion.
46 function File_Exists (Name : String) return Boolean
48 Namestr : aliased String (1 .. Name'Length + 1);
49 -- Name as given with ASCII.NUL appended
52 Namestr (1 .. Name'Length) := Name;
53 Namestr (Name'Length + 1) := ASCII.NUL;
54 return file_exists (Namestr'Address) /= 0;
63 function Get_Line return String is
64 Buffer : String (1 .. Buflen);
65 -- Buffer to read in chunks of remaining line. Will work with any
66 -- size buffer. We choose a length so that most of the time no
67 -- recursion will be required.
72 Ada.Text_IO.Get_Line (Buffer, Last);
74 -- If the buffer is not full, then we are all done
76 if Last < Buffer'Last then
77 return Buffer (1 .. Last);
79 -- Otherwise, we still have characters left on the line. Note that
80 -- as specified by (RM A.10.7(19)) the end of line is not skipped
81 -- in this case, even if we are right at it now.
84 return Buffer & GNAT.IO_Aux.Get_Line;
88 -- Case of reading from a specified file. Note that we could certainly
89 -- share code between these two versions, but these are very short
90 -- routines, and we may as well aim for maximum speed, cutting out an
91 -- intermediate call (calls returning string may be somewhat slow)
93 function Get_Line (File : Ada.Text_IO.File_Type) return String is
94 Buffer : String (1 .. Buflen);
98 Ada.Text_IO.Get_Line (File, Buffer, Last);
100 if Last < Buffer'Last then
101 return Buffer (1 .. Last);
103 return Buffer & Get_Line (File);