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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . F I L E _ I O --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2009, 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 --
-- <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. --
-- --
------------------------------------------------------------------------------
-- 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
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;
|
