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 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  15 int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
  16 {
  17         struct sysinfo info;
  18         unsigned mem_unit;
  19
  20 #if ENABLE_DESKTOP
  21         if (argv[1] && argv[1][0] == '-')
  22                 bb_show_usage();
  23 #endif
  24
  25         sysinfo(&info);
  26
  27         /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
  28         mem_unit = 1;
  29         if (info.mem_unit != 0) {
  30                 mem_unit = info.mem_unit;
  31         }
  32
  33         /* Convert values to kbytes */
  34         if (mem_unit == 1) {
  35                 info.totalram >>= 10;
  36                 info.freeram >>= 10;
  37 #if BB_MMU
  38                 info.totalswap >>= 10;
  39                 info.freeswap >>= 10;
  40 #endif
  41                 info.sharedram >>= 10;
  42                 info.bufferram >>= 10;
  43         } else {
  44                 mem_unit >>= 10;
  45                 /* TODO:  Make all this stuff not overflow when mem >= 4 Tb */
  46                 info.totalram *= mem_unit;
  47                 info.freeram *= mem_unit;
  48 #if BB_MMU
  49                 info.totalswap *= mem_unit;
  50                 info.freeswap *= mem_unit;
  51 #endif
  52                 info.sharedram *= mem_unit;
  53                 info.bufferram *= mem_unit;
  54         }
  55
  56         printf("     %13s%13s%13s%13s%13s\n",
  57                 "total",
  58                 "used",
  59                 "free",
  60                 "shared", "buffers" /* swap and total don't have these columns */
  61                 /* procps version 3.2.8 also shows "cached" column, but
  62                  * sysinfo() does not provide this value, need to parse
  63                  * /proc/meminfo instead and get "Cached: NNN kB" from there.
  64                  */
  65         );
  66 #define FIELDS_5 "%13lu%13lu%13lu%13lu%13lu\n"
  67 #define FIELDS_3 (FIELDS_5 + 2*5)
  68 #define FIELDS_2 (FIELDS_5 + 3*5)
  69         printf("Mem: ");
  70         printf(FIELDS_5,
  71                 info.totalram,
  72                 info.totalram - info.freeram,
  73                 info.freeram,
  74                 info.sharedram, info.bufferram
  75         );
  76         /* Show alternate, more meaningful busy/free numbers by counting
  77          * buffer cache as free memory (make it "-/+ buffers/cache"
  78          * if/when we add support for "cached" column): */
  79         printf("-/+ buffers:      ");
  80         printf(FIELDS_2,
  81                 info.totalram - info.freeram - info.bufferram,
  82                 info.freeram + info.bufferram
  83         );
  84 #if BB_MMU
  85         printf("Swap:");
  86         printf(FIELDS_3,
  87                 info.totalswap,
  88                 info.totalswap - info.freeswap,
  89                 info.freeswap
  90         );
  91 #endif
  92         return EXIT_SUCCESS;
  93 }