FreeNOS
read.cpp
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1/*
2 * Copyright (C) 2009 Niek Linnenbank
3 *
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <FileSystemClient.h>
19#include "errno.h"
20#include "unistd.h"
21
22ssize_t read(int fildes, void *buf, size_t nbyte)
23{
24 // Read the file.
25 const FileSystemClient filesystem;
26 const FileSystem::Result result = filesystem.readFile(fildes,
27 (char *)buf,
28 &nbyte);
29 // Did the read succeed?
30 if (result != FileSystem::Success)
31 {
32 errno = ENOENT;
33 return -1;
34 }
35
36 return nbyte;
37}
FileSystemClient provides a simple interface to a FileSystemServer.
FileSystem::Result readFile(const Size descriptor, void *buf, Size *size) const
Read a file.
#define ENOENT
No such file or directory.
Definition errno.h:178
C int errno
The lvalue errno is used by many functions to return error values.
ssize_t read(int fildes, void *buf, size_t nbyte)
Read from a file.
Definition read.cpp:22
slong ssize_t
Used for a count of bytes or an error indication.
Definition types.h:38
Result
Result code for filesystem Actions.
Definition FileSystem.h:53