FreeNOS
read.cpp
Go to the documentation of this file.
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 
22 ssize_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 }
errno
C int errno
The lvalue errno is used by many functions to return error values.
FileSystemClient
FileSystemClient provides a simple interface to a FileSystemServer.
Definition: FileSystemClient.h:42
FileSystem::Success
@ Success
Definition: FileSystem.h:54
read
ssize_t read(int fildes, void *buf, size_t nbyte)
Read from a file.
Definition: read.cpp:22
FileSystemClient::readFile
FileSystem::Result readFile(const Size descriptor, void *buf, Size *size) const
Read a file.
Definition: FileSystemClient.cpp:229
unistd.h
ENOENT
#define ENOENT
No such file or directory.
Definition: errno.h:178
FileSystemClient.h
FileSystem::Result
Result
Result code for filesystem Actions.
Definition: FileSystem.h:52
ssize_t
slong ssize_t
Used for a count of bytes or an error indication.
Definition: types.h:38
errno.h