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 #include "libbb.h"
  13
  14 struct globals {
  15         unsigned mem_unit;
  16 #if ENABLE_DESKTOP
  17         unsigned unit_steps;
  18 # define G_unit_steps G.unit_steps
  19 #else
  20 # define G_unit_steps 10
  21 #endif
  22 };
  23 #define G (*(struct globals*)&bb_common_bufsiz1)
  24 #define INIT_G() do { } while (0)
  25
  26
  27 static unsigned long long scale(unsigned long d)
  28 {
  29         return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
  30 }
  31
  32
  33 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  34 int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
  35 {
  36         struct sysinfo info;
  37
  38         INIT_G();
  39
  40 #if ENABLE_DESKTOP
  41         G.unit_steps = 10;
  42         if (argv[1] && argv[1][0] == '-') {
  43                 switch (argv[1][1]) {
  44                 case 'b':
  45                         G.unit_steps = 0;
  46                         break;
  47                 case 'k': /* 2^10 */
  48                         /* G.unit_steps = 10; - already is */
  49                         break;
  50                 case 'm': /* 2^(2*10) */
  51                         G.unit_steps = 20;
  52                         break;
  53                 case 'g': /* 2^(3*10) */
  54                         G.unit_steps = 30;
  55                         break;
  56                 default:
  57                         bb_show_usage();
  58                 }
  59         }
  60 #endif
  61
  62         sysinfo(&info);
  63
  64         /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
  65         G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
  66
  67         printf("     %13s%13s%13s%13s%13s\n",
  68                 "total",
  69                 "used",
  70                 "free",
  71                 "shared", "buffers" /* swap and total don't have these columns */
  72                 /* procps version 3.2.8 also shows "cached" column, but
  73                  * sysinfo() does not provide this value, need to parse
  74                  * /proc/meminfo instead and get "Cached: NNN kB" from there.
  75                  */
  76         );
  77
  78 #define FIELDS_5 "%13llu%13llu%13llu%13llu%13llu\n"
  79 #define FIELDS_3 (FIELDS_5 + 2*6)
  80 #define FIELDS_2 (FIELDS_5 + 3*6)
  81
  82         printf("Mem: ");
  83         printf(FIELDS_5,
  84                 scale(info.totalram),
  85                 scale(info.totalram - info.freeram),
  86                 scale(info.freeram),
  87                 scale(info.sharedram),
  88                 scale(info.bufferram)
  89         );
  90         /* Show alternate, more meaningful busy/free numbers by counting
  91          * buffer cache as free memory (make it "-/+ buffers/cache"
  92          * if/when we add support for "cached" column): */
  93         printf("-/+ buffers:      ");
  94         printf(FIELDS_2,
  95                 scale(info.totalram - info.freeram - info.bufferram),
  96                 scale(info.freeram + info.bufferram)
  97         );
  98 #if BB_MMU
  99         printf("Swap:");
 100         printf(FIELDS_3,
 101                 scale(info.totalswap),
 102                 scale(info.totalswap - info.freeswap),
 103                 scale(info.freeswap)
 104         );
 105 #endif
 106         return EXIT_SUCCESS;
 107 }