blob: ce759916faab9931355cb58791e91ad7d7cad74b
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * nice implementation for busybox |
4 | * |
5 | * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org> |
6 | * |
7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
8 | */ |
9 | |
10 | //usage:#define nice_trivial_usage |
11 | //usage: "[-n ADJUST] [PROG ARGS]" |
12 | //usage:#define nice_full_usage "\n\n" |
13 | //usage: "Change scheduling priority, run PROG\n" |
14 | //usage: "\n -n ADJUST Adjust priority by ADJUST" |
15 | |
16 | #include <sys/resource.h> |
17 | #include "libbb.h" |
18 | |
19 | int nice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
20 | int nice_main(int argc, char **argv) |
21 | { |
22 | int old_priority, adjustment; |
23 | |
24 | old_priority = getpriority(PRIO_PROCESS, 0); |
25 | |
26 | if (!*++argv) { /* No args, so (GNU) output current nice value. */ |
27 | printf("%d\n", old_priority); |
28 | fflush_stdout_and_exit(EXIT_SUCCESS); |
29 | } |
30 | |
31 | adjustment = 10; /* Set default adjustment. */ |
32 | |
33 | if (argv[0][0] == '-') { |
34 | if (argv[0][1] == 'n') { /* -n */ |
35 | if (argv[0][2]) { /* -nNNNN (w/o space) */ |
36 | argv[0] += 2; argv--; argc++; |
37 | } |
38 | } else { /* -NNN (NNN may be negative) == -n NNN */ |
39 | argv[0] += 1; argv--; argc++; |
40 | } |
41 | if (argc < 4) { /* Missing priority and/or utility! */ |
42 | bb_show_usage(); |
43 | } |
44 | adjustment = xatoi_range(argv[1], INT_MIN/2, INT_MAX/2); |
45 | argv += 2; |
46 | } |
47 | |
48 | { /* Set our priority. */ |
49 | int prio = old_priority + adjustment; |
50 | |
51 | if (setpriority(PRIO_PROCESS, 0, prio) < 0) { |
52 | bb_perror_msg_and_die("setpriority(%d)", prio); |
53 | } |
54 | } |
55 | |
56 | BB_EXECVP_or_die(argv); |
57 | } |
58 |