nmeter: fix block i/o count on newer Linux kernels
[oweals/busybox.git] / procps / free.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini free implementation for busybox
4  *
5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6  *
7  * Licensed under GPLv2, see file LICENSE in this source tree.
8  */
9
10 /* getopt not needed */
11
12 //usage:#define free_trivial_usage
13 //usage:       "" IF_DESKTOP("[-b/k/m/g]")
14 //usage:#define free_full_usage "\n\n"
15 //usage:       "Display the amount of free and used system memory"
16 //usage:
17 //usage:#define free_example_usage
18 //usage:       "$ free\n"
19 //usage:       "              total         used         free       shared      buffers\n"
20 //usage:       "  Mem:       257628       248724         8904        59644        93124\n"
21 //usage:       " Swap:       128516         8404       120112\n"
22 //usage:       "Total:       386144       257128       129016\n"
23
24 #include "libbb.h"
25 #ifdef __linux__
26 # include <sys/sysinfo.h>
27 #endif
28
29 struct globals {
30         unsigned mem_unit;
31 #if ENABLE_DESKTOP
32         unsigned unit_steps;
33 # define G_unit_steps G.unit_steps
34 #else
35 # define G_unit_steps 10
36 #endif
37 } FIX_ALIASING;
38 #define G (*(struct globals*)&bb_common_bufsiz1)
39 #define INIT_G() do { } while (0)
40
41
42 static unsigned long long scale(unsigned long d)
43 {
44         return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
45 }
46
47
48 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
49 int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
50 {
51         struct sysinfo info;
52
53         INIT_G();
54
55 #if ENABLE_DESKTOP
56         G.unit_steps = 10;
57         if (argv[1] && argv[1][0] == '-') {
58                 switch (argv[1][1]) {
59                 case 'b':
60                         G.unit_steps = 0;
61                         break;
62                 case 'k': /* 2^10 */
63                         /* G.unit_steps = 10; - already is */
64                         break;
65                 case 'm': /* 2^(2*10) */
66                         G.unit_steps = 20;
67                         break;
68                 case 'g': /* 2^(3*10) */
69                         G.unit_steps = 30;
70                         break;
71                 default:
72                         bb_show_usage();
73                 }
74         }
75 #endif
76
77         sysinfo(&info);
78
79         /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
80         G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
81
82         printf("     %13s%13s%13s%13s%13s\n",
83                 "total",
84                 "used",
85                 "free",
86                 "shared", "buffers" /* swap and total don't have these columns */
87                 /* procps version 3.2.8 also shows "cached" column, but
88                  * sysinfo() does not provide this value, need to parse
89                  * /proc/meminfo instead and get "Cached: NNN kB" from there.
90                  */
91         );
92
93 #define FIELDS_5 "%13llu%13llu%13llu%13llu%13llu\n"
94 #define FIELDS_3 (FIELDS_5 + 2*6)
95 #define FIELDS_2 (FIELDS_5 + 3*6)
96
97         printf("Mem: ");
98         printf(FIELDS_5,
99                 scale(info.totalram),
100                 scale(info.totalram - info.freeram),
101                 scale(info.freeram),
102                 scale(info.sharedram),
103                 scale(info.bufferram)
104         );
105         /* Show alternate, more meaningful busy/free numbers by counting
106          * buffer cache as free memory (make it "-/+ buffers/cache"
107          * if/when we add support for "cached" column): */
108         printf("-/+ buffers:      ");
109         printf(FIELDS_2,
110                 scale(info.totalram - info.freeram - info.bufferram),
111                 scale(info.freeram + info.bufferram)
112         );
113 #if BB_MMU
114         printf("Swap:");
115         printf(FIELDS_3,
116                 scale(info.totalswap),
117                 scale(info.totalswap - info.freeswap),
118                 scale(info.freeswap)
119         );
120 #endif
121         return EXIT_SUCCESS;
122 }