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.
29 #include <sys/resource.h>
31 #if (PRIO_PROCESS < CHAR_MIN) || (PRIO_PROCESS > CHAR_MAX)
32 #error Assumption violated : PRIO_PROCESS value
34 #if (PRIO_PGRP < CHAR_MIN) || (PRIO_PGRP > CHAR_MAX)
35 #error Assumption violated : PRIO_PGRP value
37 #if (PRIO_USER < CHAR_MIN) || (PRIO_USER > CHAR_MAX)
38 #error Assumption violated : PRIO_USER value
41 int renice_main(int argc, char **argv)
43 static const char Xetpriority_msg[] = "%cetpriority";
45 int retval = EXIT_SUCCESS;
46 int which = PRIO_PROCESS; /* Default 'which' value. */
48 int adjustment, new_priority;
54 /* Check if we are using a relative adjustment. */
55 if (arg && arg[0] == '-' && arg[1] == 'n') {
63 if (!arg) { /* No args? Then show usage. */
67 /* Get the priority adjustment (absolute or relative). */
68 adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
70 while ((arg = *++argv) != NULL) {
71 /* Check for a mode switch. */
72 if (arg[0] == '-' && arg[1]) {
73 static const char opts[]
74 = { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
75 const char *p = strchr(opts, arg[1]);
84 /* Process an ID arg. */
85 if (which == PRIO_USER) {
89 bb_error_msg("unknown user: %s", arg);
94 if (safe_strtou(arg, &who)) {
95 bb_error_msg("bad value: %s", arg);
100 /* Get priority to use, and set it. */
104 errno = 0; /* Needed for getpriority error detection. */
105 old_priority = getpriority(which, who);
107 bb_perror_msg(Xetpriority_msg, 'g');
111 new_priority = old_priority + adjustment;
113 new_priority = adjustment;
116 if (setpriority(which, who, new_priority) == 0) {
120 bb_perror_msg(Xetpriority_msg, 's');
122 retval = EXIT_FAILURE;
125 /* No need to check for errors outputing to stderr since, if it
126 * was used, the HAD_ERROR label was reached and retval was set. */