jcs.org
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 <stdio.h>
28#include <unistd.h>
29
30int main(int, char**)
31{
32 if (pledge("stdio rpath", nullptr) < 0) {
33 perror("pledge");
34 return 1;
35 }
36
37 FILE* fp = fopen("/proc/uptime", "r");
38 if (!fp) {
39 perror("fopen(/proc/uptime)");
40 return 1;
41 }
42
43 if (pledge("stdio", nullptr) < 0) {
44 perror("pledge");
45 return 1;
46 }
47
48 char buffer[BUFSIZ];
49 auto* p = fgets(buffer, sizeof(buffer), fp);
50 if (!p) {
51 perror("fgets");
52 return 1;
53 }
54
55 unsigned seconds;
56 sscanf(buffer, "%u", &seconds);
57
58 printf("Up ");
59
60 if (seconds / 86400 > 0) {
61 printf("%d day%s, ", seconds / 86400, (seconds / 86400) == 1 ? "" : "s");
62 seconds %= 86400;
63 }
64
65 if (seconds / 3600 > 0) {
66 printf("%d hour%s, ", seconds / 3600, (seconds / 3600) == 1 ? "" : "s");
67 seconds %= 3600;
68 }
69
70 if (seconds / 60 > 0) {
71 printf("%d minute%s, ", seconds / 60, (seconds / 60) == 1 ? "" : "s");
72 seconds %= 60;
73 }
74
75 printf("%d second%s\n", seconds, seconds == 1 ? "" : "s");
76
77 fclose(fp);
78 return 0;
79}