blob: 3676ee6630448db87b0d94b9b1bf59f3a7e9e494
| 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 | //config:config NICE |
| 10 | //config: bool "nice" |
| 11 | //config: default y |
| 12 | //config: help |
| 13 | //config: nice runs a program with modified scheduling priority. |
| 14 | |
| 15 | //applet:IF_NICE(APPLET(nice, BB_DIR_BIN, BB_SUID_DROP)) |
| 16 | |
| 17 | //kbuild:lib-$(CONFIG_NICE) += nice.o |
| 18 | |
| 19 | //usage:#define nice_trivial_usage |
| 20 | //usage: "[-n ADJUST] [PROG ARGS]" |
| 21 | //usage:#define nice_full_usage "\n\n" |
| 22 | //usage: "Change scheduling priority, run PROG\n" |
| 23 | //usage: "\n -n ADJUST Adjust priority by ADJUST" |
| 24 | |
| 25 | #include <sys/resource.h> |
| 26 | #include "libbb.h" |
| 27 | |
| 28 | int nice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 29 | int nice_main(int argc, char **argv) |
| 30 | { |
| 31 | int old_priority, adjustment; |
| 32 | |
| 33 | old_priority = getpriority(PRIO_PROCESS, 0); |
| 34 | |
| 35 | if (!*++argv) { /* No args, so (GNU) output current nice value. */ |
| 36 | printf("%d\n", old_priority); |
| 37 | fflush_stdout_and_exit(EXIT_SUCCESS); |
| 38 | } |
| 39 | |
| 40 | adjustment = 10; /* Set default adjustment. */ |
| 41 | |
| 42 | if (argv[0][0] == '-') { |
| 43 | if (argv[0][1] == 'n') { /* -n */ |
| 44 | if (argv[0][2]) { /* -nNNNN (w/o space) */ |
| 45 | argv[0] += 2; argv--; argc++; |
| 46 | } |
| 47 | } else { /* -NNN (NNN may be negative) == -n NNN */ |
| 48 | argv[0] += 1; argv--; argc++; |
| 49 | } |
| 50 | if (argc < 4) { /* Missing priority and/or utility! */ |
| 51 | bb_show_usage(); |
| 52 | } |
| 53 | adjustment = xatoi_range(argv[1], INT_MIN/2, INT_MAX/2); |
| 54 | argv += 2; |
| 55 | } |
| 56 | |
| 57 | { /* Set our priority. */ |
| 58 | int prio = old_priority + adjustment; |
| 59 | |
| 60 | if (setpriority(PRIO_PROCESS, 0, prio) < 0) { |
| 61 | bb_perror_msg_and_die("setpriority(%d)", prio); |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | BB_EXECVP_or_die(argv); |
| 66 | } |
| 67 |