1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- G N A T . I O _ A U X --
-- --
-- B o d y --
-- --
-- Copyright (C) 1995-2010, AdaCore --
-- --
-- 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 --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Interfaces.C_Streams; use Interfaces.C_Streams;
package body GNAT.IO_Aux is
Buflen : constant := 2000;
-- Buffer length. Works for any non-zero value, larger values take
-- more stack space, smaller values require more recursion.
-----------------
-- File_Exists --
-----------------
function File_Exists (Name : String) return Boolean
is
Namestr : aliased String (1 .. Name'Length + 1);
-- Name as given with ASCII.NUL appended
begin
Namestr (1 .. Name'Length) := Name;
Namestr (Name'Length + 1) := ASCII.NUL;
return file_exists (Namestr'Address) /= 0;
end File_Exists;
--------------
-- Get_Line --
--------------
-- Current_Input case
function Get_Line return String is
Buffer : String (1 .. Buflen);
-- Buffer to read in chunks of remaining line. Will work with any
-- size buffer. We choose a length so that most of the time no
-- recursion will be required.
Last : Natural;
begin
Ada.Text_IO.Get_Line (Buffer, Last);
-- If the buffer is not full, then we are all done
if Last < Buffer'Last then
return Buffer (1 .. Last);
-- Otherwise, we still have characters left on the line. Note that
-- as specified by (RM A.10.7(19)) the end of line is not skipped
-- in this case, even if we are right at it now.
else
return Buffer & GNAT.IO_Aux.Get_Line;
end if;
end Get_Line;
-- Case of reading from a specified file. Note that we could certainly
-- share code between these two versions, but these are very short
-- routines, and we may as well aim for maximum speed, cutting out an
-- intermediate call (calls returning string may be somewhat slow)
function Get_Line (File : Ada.Text_IO.File_Type) return String is
Buffer : String (1 .. Buflen);
Last : Natural;
begin
Ada.Text_IO.Get_Line (File, Buffer, Last);
if Last < Buffer'Last then
return Buffer (1 .. Last);
else
return Buffer & Get_Line (File);
end if;
end Get_Line;
end GNAT.IO_Aux;
|
