1 /* vi: set sw=4 ts=4: */
3 * renice 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.
11 * Setting an absolute priority was obsoleted in SUSv2 and removed
12 * in SUSv3. However, the common linux version of renice does
13 * absolute and not relative. So we'll continue supporting absolute,
14 * although the stdout logging has been removed since both SUSv2 and
15 * SUSv3 specify that stdout isn't used.
17 * This version is lenient in that it doesn't require any IDs. The
18 * options -p, -g, and -u are treated as mode switches for the
19 * following IDs (if any). Multiple switches are allowed.
22 //usage:#define renice_trivial_usage
23 //usage: "[-n] PRIORITY [[-p | -g | -u] ID...]..."
24 //usage:#define renice_full_usage "\n\n"
25 //usage: "Change scheduling priority of a running process\n"
26 //usage: "\n -n Add PRIORITY to current nice value"
27 //usage: "\n Without -n, nice value is set to PRIORITY"
28 //usage: "\n -p Process ids (default)"
29 //usage: "\n -g Process group ids"
30 //usage: "\n -u Process user names"
33 #include <sys/resource.h>
35 void BUG_bad_PRIO_PROCESS(void);
36 void BUG_bad_PRIO_PGRP(void);
37 void BUG_bad_PRIO_USER(void);
39 int renice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
40 int renice_main(int argc UNUSED_PARAM, char **argv)
42 static const char Xetpriority_msg[] ALIGN1 = "%cetpriority";
44 int retval = EXIT_SUCCESS;
45 int which = PRIO_PROCESS; /* Default 'which' value. */
47 int adjustment, new_priority;
51 /* Yes, they are not #defines in glibc 2.4! #if won't work */
52 if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX)
53 BUG_bad_PRIO_PROCESS();
54 if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX)
56 if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX)
61 /* Check if we are using a relative adjustment. */
62 if (arg && arg[0] == '-' && arg[1] == 'n') {
70 if (!arg) { /* No args? Then show usage. */
74 /* Get the priority adjustment (absolute or relative). */
75 adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
77 while ((arg = *++argv) != NULL) {
78 /* Check for a mode switch. */
79 if (arg[0] == '-' && arg[1]) {
80 static const char opts[] ALIGN1 = {
81 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER
83 const char *p = strchr(opts, arg[1]);
92 /* Process an ID arg. */
93 if (which == PRIO_USER) {
97 bb_error_msg("unknown user %s", arg);
102 who = bb_strtou(arg, NULL, 10);
104 bb_error_msg("invalid number '%s'", arg);
109 /* Get priority to use, and set it. */
113 errno = 0; /* Needed for getpriority error detection. */
114 old_priority = getpriority(which, who);
116 bb_perror_msg(Xetpriority_msg, 'g');
120 new_priority = old_priority + adjustment;
122 new_priority = adjustment;
125 if (setpriority(which, who, new_priority) == 0) {
129 bb_perror_msg(Xetpriority_msg, 's');
131 retval = EXIT_FAILURE;
134 /* No need to check for errors outputing to stderr since, if it
135 * was used, the HAD_ERROR label was reached and retval was set. */