procps/free.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini free implementation for busybox
   4  *
   5  * Copyright (C) 1999,2000 by Lineo, inc.
   6  * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  *
  22  */
  23
  24 #include "internal.h"
  25 #include <stdio.h>
  26 #include <errno.h>
  27
  28 const char free_usage[] =
  29         "free\n"
  30 #ifndef BB_FEATURE_TRIVIAL_HELP
  31         "\nDisplays the amount of free and used system memory\n"
  32 #endif
  33         ;
  34
  35 extern int free_main(int argc, char **argv)
  36 {
  37         struct sysinfo info;
  38         sysinfo(&info);
  39         /* Kernels prior to 2.4.x will return info.mem_unit==0.  Kernels after
  40          * 2.4.x actually fill this value in */
  41         if (info.mem_unit==0) {
  42                 /* Looks like we have a kernel prior to Linux 2.4.x */
  43                 info.mem_unit=1024;
  44                 info.totalram/=info.mem_unit;
  45                 info.freeram/=info.mem_unit;
  46                 info.totalswap/=info.mem_unit;
  47                 info.freeswap/=info.mem_unit;
  48                 info.sharedram/=info.mem_unit;
  49                 info.bufferram/=info.mem_unit;
  50         } else {
  51                 /* Bah. Linux 2.4.x completely changed sysinfo. This can in theory
  52                 overflow a 32 bit unsigned long, but who puts more then 4GiB ram+swap
  53                 on an embedded system? */
  54                 info.mem_unit/=1024;
  55                 info.totalram*=info.mem_unit;
  56                 info.freeram*=info.mem_unit;
  57                 info.totalswap*=info.mem_unit;
  58                 info.freeswap*=info.mem_unit;
  59                 info.sharedram*=info.mem_unit;
  60                 info.bufferram*=info.mem_unit;
  61         }
  62         if (argc > 1 && **(argv + 1) == '-')
  63                 usage(free_usage);
  64
  65         printf("%6s%13s%13s%13s%13s%13s\n", "", "total", "used", "free",
  66                         "shared", "buffers");
  67
  68         printf("%6s%13ld%13ld%13ld%13ld%13ld\n", "Mem:", info.totalram,
  69                         info.totalram-info.freeram, info.freeram,
  70                         info.sharedram, info.bufferram);
  71
  72         printf("%6s%13ld%13ld%13ld\n", "Swap:", info.totalswap,
  73                         info.totalswap-info.freeswap, info.freeswap);
  74
  75         printf("%6s%13ld%13ld%13ld\n", "Total:", info.totalram+info.totalswap,
  76                         (info.totalram-info.freeram)+(info.totalswap-info.freeswap),
  77                         info.freeram+info.freeswap);
  78         return(TRUE);
  79 }
  80
  81