busybox/procps/free.c

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/* vi: set sw=4 ts=4: */
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/*
* Mini free implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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*
* Licensed under the GPL version 2, see the file LICENSE in this tarball.
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*/
/* getopt not needed */
#include "libbb.h"
int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
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{
struct sysinfo info;
unsigned mem_unit;
#if ENABLE_DESKTOP
if (argv[1] && argv[1][0] == '-')
bb_show_usage();
#endif
sysinfo(&info);
/* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
mem_unit = 1;
if (info.mem_unit != 0) {
mem_unit = info.mem_unit;
}
/* Convert values to kbytes */
if (mem_unit == 1) {
info.totalram >>= 10;
info.freeram >>= 10;
#if BB_MMU
info.totalswap >>= 10;
info.freeswap >>= 10;
#endif
info.sharedram >>= 10;
info.bufferram >>= 10;
} else {
mem_unit >>= 10;
/* TODO: Make all this stuff not overflow when mem >= 4 Tb */
info.totalram *= mem_unit;
info.freeram *= mem_unit;
#if BB_MMU
info.totalswap *= mem_unit;
info.freeswap *= mem_unit;
#endif
info.sharedram *= mem_unit;
info.bufferram *= mem_unit;
}
printf(" %13s%13s%13s%13s%13s\n",
"total",
"used",
"free",
"shared", "buffers" /* swap and total don't have these columns */
/* procps version 3.2.8 also shows "cached" column, but
* sysinfo() does not provide this value, need to parse
* /proc/meminfo instead and get "Cached: NNN kB" from there.
*/
);
#define FIELDS_5 "%13lu%13lu%13lu%13lu%13lu\n"
#define FIELDS_3 (FIELDS_5 + 2*5)
#define FIELDS_2 (FIELDS_5 + 3*5)
printf("Mem: ");
printf(FIELDS_5,
info.totalram,
info.totalram - info.freeram,
info.freeram,
info.sharedram, info.bufferram
);
/* Show alternate, more meaningful busy/free numbers by counting
* buffer cache as free memory (make it "-/+ buffers/cache"
* if/when we add support for "cached" column): */
printf("-/+ buffers: ");
printf(FIELDS_2,
info.totalram - info.freeram - info.bufferram,
info.freeram + info.bufferram
);
#if BB_MMU
printf("Swap:");
printf(FIELDS_3,
info.totalswap,
info.totalswap - info.freeswap,
info.freeswap
);
#endif
return EXIT_SUCCESS;
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}