Contents of /tags/mkinitrd-6_3_5/busybox/procps/renice.c
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Sat Jan 29 14:06:54 2011 UTC (13 years, 8 months ago) by niro
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Sat Jan 29 14:06:54 2011 UTC (13 years, 8 months ago) by niro
File MIME type: text/plain
File size: 3234 byte(s)
tagged 'mkinitrd-6_3_5'
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 "libbb.h" |
23 | #include <sys/resource.h> |
24 | |
25 | void BUG_bad_PRIO_PROCESS(void); |
26 | void BUG_bad_PRIO_PGRP(void); |
27 | void BUG_bad_PRIO_USER(void); |
28 | |
29 | int renice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
30 | int renice_main(int argc UNUSED_PARAM, char **argv) |
31 | { |
32 | static const char Xetpriority_msg[] ALIGN1 = "%cetpriority"; |
33 | |
34 | int retval = EXIT_SUCCESS; |
35 | int which = PRIO_PROCESS; /* Default 'which' value. */ |
36 | int use_relative = 0; |
37 | int adjustment, new_priority; |
38 | unsigned who; |
39 | char *arg; |
40 | |
41 | /* Yes, they are not #defines in glibc 2.4! #if won't work */ |
42 | if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX) |
43 | BUG_bad_PRIO_PROCESS(); |
44 | if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX) |
45 | BUG_bad_PRIO_PGRP(); |
46 | if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX) |
47 | BUG_bad_PRIO_USER(); |
48 | |
49 | arg = *++argv; |
50 | |
51 | /* Check if we are using a relative adjustment. */ |
52 | if (arg && arg[0] == '-' && arg[1] == 'n') { |
53 | use_relative = 1; |
54 | if (!arg[2]) |
55 | arg = *++argv; |
56 | else |
57 | arg += 2; |
58 | } |
59 | |
60 | if (!arg) { /* No args? Then show usage. */ |
61 | bb_show_usage(); |
62 | } |
63 | |
64 | /* Get the priority adjustment (absolute or relative). */ |
65 | adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2); |
66 | |
67 | while ((arg = *++argv) != NULL) { |
68 | /* Check for a mode switch. */ |
69 | if (arg[0] == '-' && arg[1]) { |
70 | static const char opts[] ALIGN1 = { |
71 | 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER |
72 | }; |
73 | const char *p = strchr(opts, arg[1]); |
74 | if (p) { |
75 | which = p[4]; |
76 | if (!arg[2]) |
77 | continue; |
78 | arg += 2; |
79 | } |
80 | } |
81 | |
82 | /* Process an ID arg. */ |
83 | if (which == PRIO_USER) { |
84 | struct passwd *p; |
85 | p = getpwnam(arg); |
86 | if (!p) { |
87 | bb_error_msg("unknown user %s", arg); |
88 | goto HAD_ERROR; |
89 | } |
90 | who = p->pw_uid; |
91 | } else { |
92 | who = bb_strtou(arg, NULL, 10); |
93 | if (errno) { |
94 | bb_error_msg("bad value: %s", arg); |
95 | goto HAD_ERROR; |
96 | } |
97 | } |
98 | |
99 | /* Get priority to use, and set it. */ |
100 | if (use_relative) { |
101 | int old_priority; |
102 | |
103 | errno = 0; /* Needed for getpriority error detection. */ |
104 | old_priority = getpriority(which, who); |
105 | if (errno) { |
106 | bb_perror_msg(Xetpriority_msg, 'g'); |
107 | goto HAD_ERROR; |
108 | } |
109 | |
110 | new_priority = old_priority + adjustment; |
111 | } else { |
112 | new_priority = adjustment; |
113 | } |
114 | |
115 | if (setpriority(which, who, new_priority) == 0) { |
116 | continue; |
117 | } |
118 | |
119 | bb_perror_msg(Xetpriority_msg, 's'); |
120 | HAD_ERROR: |
121 | retval = EXIT_FAILURE; |
122 | } |
123 | |
124 | /* No need to check for errors outputing to stderr since, if it |
125 | * was used, the HAD_ERROR label was reached and retval was set. */ |
126 | |
127 | return retval; |
128 | } |