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 the GPL v2 or later, see the file LICENSE in this tarball.
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.
23 #include <sys/resource.h>
25 void BUG_bad_PRIO_PROCESS(void);
26 void BUG_bad_PRIO_PGRP(void);
27 void BUG_bad_PRIO_USER(void);
29 int renice_main(int argc, char **argv)
31 static const char Xetpriority_msg[] = "%cetpriority";
33 int retval = EXIT_SUCCESS;
34 int which = PRIO_PROCESS; /* Default 'which' value. */
36 int adjustment, new_priority;
40 /* Yes, they are not #defines in glibc 2.4! #if won't work */
41 if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX)
42 BUG_bad_PRIO_PROCESS();
43 if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX)
45 if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX)
50 /* Check if we are using a relative adjustment. */
51 if (arg && arg[0] == '-' && arg[1] == 'n') {
59 if (!arg) { /* No args? Then show usage. */
63 /* Get the priority adjustment (absolute or relative). */
64 adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
66 while ((arg = *++argv) != NULL) {
67 /* Check for a mode switch. */
68 if (arg[0] == '-' && arg[1]) {
69 static const char opts[]
70 = { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
71 const char *p = strchr(opts, arg[1]);
80 /* Process an ID arg. */
81 if (which == PRIO_USER) {
85 bb_error_msg("unknown user: %s", arg);
90 who = bb_strtou(arg, NULL, 10);
92 bb_error_msg("bad value: %s", arg);
97 /* Get priority to use, and set it. */
101 errno = 0; /* Needed for getpriority error detection. */
102 old_priority = getpriority(which, who);
104 bb_perror_msg(Xetpriority_msg, 'g');
108 new_priority = old_priority + adjustment;
110 new_priority = adjustment;
113 if (setpriority(which, who, new_priority) == 0) {
117 bb_perror_msg(Xetpriority_msg, 's');
119 retval = EXIT_FAILURE;
122 /* No need to check for errors outputing to stderr since, if it
123 * was used, the HAD_ERROR label was reached and retval was set. */