[821] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * renice implementation for busybox
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| 4 | *
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| 5 | * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
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| 6 | *
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| 7 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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| 8 | */
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| 9 |
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| 10 | /* Notes:
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| 11 | * Setting an absolute priority was obsoleted in SUSv2 and removed
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| 12 | * in SUSv3. However, the common linux version of renice does
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| 13 | * absolute and not relative. So we'll continue supporting absolute,
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| 14 | * although the stdout logging has been removed since both SUSv2 and
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| 15 | * SUSv3 specify that stdout isn't used.
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| 16 | *
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| 17 | * This version is lenient in that it doesn't require any IDs. The
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| 18 | * options -p, -g, and -u are treated as mode switches for the
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| 19 | * following IDs (if any). Multiple switches are allowed.
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| 20 | */
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| 21 |
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[1765] | 22 | #include "libbb.h"
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[821] | 23 | #include <sys/resource.h>
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| 24 |
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[1765] | 25 | void BUG_bad_PRIO_PROCESS(void);
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| 26 | void BUG_bad_PRIO_PGRP(void);
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| 27 | void BUG_bad_PRIO_USER(void);
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[821] | 28 |
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[1765] | 29 | int renice_main(int argc, char **argv);
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[821] | 30 | int renice_main(int argc, char **argv)
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| 31 | {
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[1765] | 32 | static const char Xetpriority_msg[] ALIGN1 = "%cetpriority";
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[821] | 33 |
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| 34 | int retval = EXIT_SUCCESS;
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| 35 | int which = PRIO_PROCESS; /* Default 'which' value. */
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| 36 | int use_relative = 0;
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| 37 | int adjustment, new_priority;
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[1765] | 38 | unsigned who;
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| 39 | char *arg;
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[821] | 40 |
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[1765] | 41 | /* Yes, they are not #defines in glibc 2.4! #if won't work */
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| 42 | if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX)
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| 43 | BUG_bad_PRIO_PROCESS();
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| 44 | if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX)
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| 45 | BUG_bad_PRIO_PGRP();
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| 46 | if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX)
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| 47 | BUG_bad_PRIO_USER();
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[821] | 48 |
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[1765] | 49 | arg = *++argv;
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| 50 |
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[821] | 51 | /* Check if we are using a relative adjustment. */
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[1765] | 52 | if (arg && arg[0] == '-' && arg[1] == 'n') {
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[821] | 53 | use_relative = 1;
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[1765] | 54 | if (!arg[2])
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| 55 | arg = *++argv;
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| 56 | else
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| 57 | arg += 2;
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[821] | 58 | }
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| 59 |
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[1765] | 60 | if (!arg) { /* No args? Then show usage. */
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[821] | 61 | bb_show_usage();
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| 62 | }
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| 63 |
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| 64 | /* Get the priority adjustment (absolute or relative). */
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[1765] | 65 | adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
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[821] | 66 |
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[1765] | 67 | while ((arg = *++argv) != NULL) {
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[821] | 68 | /* Check for a mode switch. */
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[1765] | 69 | if (arg[0] == '-' && arg[1]) {
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| 70 | static const char opts[] ALIGN1 = {
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| 71 | 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER
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| 72 | };
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| 73 | const char *p = strchr(opts, arg[1]);
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| 74 | if (p) {
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[821] | 75 | which = p[4];
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[1765] | 76 | if (!arg[2])
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| 77 | continue;
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| 78 | arg += 2;
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[821] | 79 | }
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| 80 | }
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| 81 |
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| 82 | /* Process an ID arg. */
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| 83 | if (which == PRIO_USER) {
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| 84 | struct passwd *p;
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[1765] | 85 | p = getpwnam(arg);
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| 86 | if (!p) {
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| 87 | bb_error_msg("unknown user: %s", arg);
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[821] | 88 | goto HAD_ERROR;
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| 89 | }
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| 90 | who = p->pw_uid;
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| 91 | } else {
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[1765] | 92 | who = bb_strtou(arg, NULL, 10);
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| 93 | if (errno) {
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| 94 | bb_error_msg("bad value: %s", arg);
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[821] | 95 | goto HAD_ERROR;
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| 96 | }
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| 97 | }
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| 98 |
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| 99 | /* Get priority to use, and set it. */
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| 100 | if (use_relative) {
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| 101 | int old_priority;
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| 102 |
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| 103 | errno = 0; /* Needed for getpriority error detection. */
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| 104 | old_priority = getpriority(which, who);
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| 105 | if (errno) {
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[1765] | 106 | bb_perror_msg(Xetpriority_msg, 'g');
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[821] | 107 | goto HAD_ERROR;
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| 108 | }
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| 109 |
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[1765] | 110 | new_priority = old_priority + adjustment;
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[821] | 111 | } else {
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| 112 | new_priority = adjustment;
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| 113 | }
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| 114 |
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| 115 | if (setpriority(which, who, new_priority) == 0) {
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| 116 | continue;
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| 117 | }
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| 118 |
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[1765] | 119 | bb_perror_msg(Xetpriority_msg, 's');
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| 120 | HAD_ERROR:
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[821] | 121 | retval = EXIT_FAILURE;
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| 122 | }
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| 123 |
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| 124 | /* No need to check for errors outputing to stderr since, if it
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| 125 | * was used, the HAD_ERROR label was reached and retval was set. */
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| 126 |
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| 127 | return retval;
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| 128 | }
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