source: MondoRescue/branches/stable/mindi-busybox/procps/renice.c @ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 14 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

File size: 3.3 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 the GPL v2 or later, see the file LICENSE in this tarball.
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#include "busybox.h"
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26#include <limits.h>
27#include <errno.h>
28#include <unistd.h>
29#include <sys/resource.h>
30
31#if (PRIO_PROCESS < CHAR_MIN) || (PRIO_PROCESS > CHAR_MAX)
32#error Assumption violated : PRIO_PROCESS value
33#endif
34#if (PRIO_PGRP < CHAR_MIN) || (PRIO_PGRP > CHAR_MAX)
35#error Assumption violated : PRIO_PGRP value
36#endif
37#if (PRIO_USER < CHAR_MIN) || (PRIO_USER > CHAR_MAX)
38#error Assumption violated : PRIO_USER value
39#endif
40
41static inline int int_add_no_wrap(int a, int b)
42{
43    int s = a + b;
44
45    if (b < 0) {
46        if (s > a) s = INT_MIN;
47    } else {
48        if (s < a) s = INT_MAX;
49    }
50
51    return s;
52}
53
54int renice_main(int argc, char **argv)
55{
56    static const char Xetpriority_msg[] = "%d : %cetpriority";
57
58    int retval = EXIT_SUCCESS;
59    int which = PRIO_PROCESS;   /* Default 'which' value. */
60    int use_relative = 0;
61    int adjustment, new_priority;
62    id_t who;
63
64    ++argv;
65
66    /* Check if we are using a relative adjustment. */
67    if (argv[0] && (argv[0][0] == '-') && (argv[0][1] == 'n') && !argv[0][2]) {
68        use_relative = 1;
69        ++argv;
70    }
71
72    if (!*argv) {               /* No args?  Then show usage. */
73        bb_show_usage();
74    }
75
76    /* Get the priority adjustment (absolute or relative). */
77    adjustment = bb_xgetlarg(*argv, 10, INT_MIN, INT_MAX);
78
79    while (*++argv) {
80        /* Check for a mode switch. */
81        if ((argv[0][0] == '-') && argv[0][1] && !argv[0][2]) {
82            static const char opts[]
83                = { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
84            const char *p;
85            if ((p = strchr(opts, argv[0][1]))) {
86                which = p[4];
87                continue;
88            }
89        }
90
91        /* Process an ID arg. */
92        if (which == PRIO_USER) {
93            struct passwd *p;
94            if (!(p = getpwnam(*argv))) {
95                bb_error_msg("unknown user: %s", *argv);
96                goto HAD_ERROR;
97            }
98            who = p->pw_uid;
99        } else {
100            char *e;
101            errno = 0;
102            who = strtoul(*argv, &e, 10);
103            if (*e || (*argv == e) || errno) {
104                bb_error_msg("bad value: %s", *argv);
105                goto HAD_ERROR;
106            }
107        }
108
109        /* Get priority to use, and set it. */
110        if (use_relative) {
111            int old_priority;
112
113            errno = 0;   /* Needed for getpriority error detection. */
114            old_priority = getpriority(which, who);
115            if (errno) {
116                bb_perror_msg(Xetpriority_msg, who, 'g');
117                goto HAD_ERROR;
118            }
119
120            new_priority = int_add_no_wrap(old_priority, adjustment);
121        } else {
122            new_priority = adjustment;
123        }
124
125        if (setpriority(which, who, new_priority) == 0) {
126            continue;
127        }
128
129        bb_perror_msg(Xetpriority_msg, who, 's');
130    HAD_ERROR:
131        retval = EXIT_FAILURE;
132    }
133
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. */
136
137    return retval;
138}
Note: See TracBrowser for help on using the repository browser.