LXR busybox/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
  29struct 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
  42static unsigned long long scale(unsigned long d)
  43{
  44        return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
  45}
  46
  47
  48int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  49int 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}
 123