source: branches/3.2/mindi-busybox/procps/renice.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 3.6 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * renice 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
10/* Notes:
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.
16 *
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.
20 */
21
22//usage:#define renice_trivial_usage
23//usage:       "{{-n INCREMENT} | PRIORITY} [[-p | -g | -u] ID...]"
24//usage:#define renice_full_usage "\n\n"
25//usage:       "Change scheduling priority for a running process\n"
26//usage:     "\n    -n  Adjust current nice value (smaller is faster)"
27//usage:     "\n    -p  Process id(s) (default)"
28//usage:     "\n    -g  Process group id(s)"
29//usage:     "\n    -u  Process user name(s) and/or id(s)"
30
31#include "libbb.h"
32#include <sys/resource.h>
33
34void BUG_bad_PRIO_PROCESS(void);
35void BUG_bad_PRIO_PGRP(void);
36void BUG_bad_PRIO_USER(void);
37
38int renice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
39int renice_main(int argc UNUSED_PARAM, char **argv)
40{
41    static const char Xetpriority_msg[] ALIGN1 = "%cetpriority";
42
43    int retval = EXIT_SUCCESS;
44    int which = PRIO_PROCESS;  /* Default 'which' value. */
45    int use_relative = 0;
46    int adjustment, new_priority;
47    unsigned who;
48    char *arg;
49
50    /* Yes, they are not #defines in glibc 2.4! #if won't work */
51    if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX)
52        BUG_bad_PRIO_PROCESS();
53    if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX)
54        BUG_bad_PRIO_PGRP();
55    if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX)
56        BUG_bad_PRIO_USER();
57
58    arg = *++argv;
59
60    /* Check if we are using a relative adjustment. */
61    if (arg && arg[0] == '-' && arg[1] == 'n') {
62        use_relative = 1;
63        if (!arg[2])
64            arg = *++argv;
65        else
66            arg += 2;
67    }
68
69    if (!arg) {  /* No args?  Then show usage. */
70        bb_show_usage();
71    }
72
73    /* Get the priority adjustment (absolute or relative). */
74    adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
75
76    while ((arg = *++argv) != NULL) {
77        /* Check for a mode switch. */
78        if (arg[0] == '-' && arg[1]) {
79            static const char opts[] ALIGN1 = {
80                'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER
81            };
82            const char *p = strchr(opts, arg[1]);
83            if (p) {
84                which = p[4];
85                if (!arg[2])
86                    continue;
87                arg += 2;
88            }
89        }
90
91        /* Process an ID arg. */
92        if (which == PRIO_USER) {
93            struct passwd *p;
94            p = getpwnam(arg);
95            if (!p) {
96                bb_error_msg("unknown user %s", arg);
97                goto HAD_ERROR;
98            }
99            who = p->pw_uid;
100        } else {
101            who = bb_strtou(arg, NULL, 10);
102            if (errno) {
103                bb_error_msg("invalid number '%s'", arg);
104                goto HAD_ERROR;
105            }
106        }
107
108        /* Get priority to use, and set it. */
109        if (use_relative) {
110            int old_priority;
111
112            errno = 0;  /* Needed for getpriority error detection. */
113            old_priority = getpriority(which, who);
114            if (errno) {
115                bb_perror_msg(Xetpriority_msg, 'g');
116                goto HAD_ERROR;
117            }
118
119            new_priority = old_priority + adjustment;
120        } else {
121            new_priority = adjustment;
122        }
123
124        if (setpriority(which, who, new_priority) == 0) {
125            continue;
126        }
127
128        bb_perror_msg(Xetpriority_msg, 's');
129 HAD_ERROR:
130        retval = EXIT_FAILURE;
131    }
132
133    /* No need to check for errors outputing to stderr since, if it
134     * was used, the HAD_ERROR label was reached and retval was set. */
135
136    return retval;
137}
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