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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/ByteBuffer.h>
28#include <LibCore/File.h>
29#include <assert.h>
30#include <fcntl.h>
31#include <stdio.h>
32#include <unistd.h>
33
34int main(int argc, char** argv)
35{
36 if (pledge("stdio rpath", nullptr) < 0) {
37 perror("pledge");
38 return 1;
39 }
40
41 if (unveil("/proc/dmesg", "r") < 0) {
42 perror("unveil");
43 return 1;
44 }
45
46 unveil(nullptr, nullptr);
47
48 (void)argc;
49 (void)argv;
50 auto f = Core::File::construct("/proc/dmesg");
51 if (!f->open(Core::IODevice::ReadOnly)) {
52 fprintf(stderr, "open: failed to open /proc/dmesg: %s\n", f->error_string());
53 return 1;
54 }
55 const auto& b = f->read_all();
56 for (size_t i = 0; i < b.size(); ++i)
57 putchar(b[i]);
58 return 0;
59}