1 /* vi: set sw=4 ts=4: */
3 * nice implementation for busybox
5 * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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"
15 //usage: "\n -n ADJUST Adjust priority by ADJUST"
17 #include <sys/resource.h>
20 int nice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
21 int nice_main(int argc, char **argv)
23 int old_priority, adjustment;
25 old_priority = getpriority(PRIO_PROCESS, 0);
27 if (!*++argv) { /* No args, so (GNU) output current nice value. */
28 printf("%d\n", old_priority);
29 fflush_stdout_and_exit(EXIT_SUCCESS);
32 adjustment = 10; /* Set default adjustment. */
34 if (argv[0][0] == '-') {
35 if (argv[0][1] == 'n') { /* -n */
36 if (argv[0][2]) { /* -nNNNN (w/o space) */
37 argv[0] += 2; argv--; argc++;
39 } else { /* -NNN (NNN may be negative) == -n NNN */
40 argv[0] += 1; argv--; argc++;
42 if (argc < 4) { /* Missing priority and/or utility! */
45 adjustment = xatoi_range(argv[1], INT_MIN/2, INT_MAX/2);
49 { /* Set our priority. */
50 int prio = old_priority + adjustment;
52 if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
53 bb_perror_msg_and_die("setpriority(%d)", prio);
57 BB_EXECVP_or_die(argv);