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/* vi: set sw=4 ts=4: */
/*
* Mini free implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config FREE
//config: bool "free (3.8 kb)"
//config: default y
//config: help
//config: free displays the total amount of free and used physical and swap
//config: memory in the system, as well as the buffers used by the kernel.
//config: The shared memory column should be ignored; it is obsolete.
//applet:IF_FREE(APPLET_NOFORK(free, free, BB_DIR_USR_BIN, BB_SUID_DROP, free))
//kbuild:lib-$(CONFIG_FREE) += free.o
//usage:#define free_trivial_usage
//usage: "" IF_DESKTOP("[-bkmgh]")
//usage:#define free_full_usage "\n\n"
//usage: "Display free and used memory"
//usage:
//usage:#define free_example_usage
//usage: "$ free\n"
//usage: " total used free shared buffers\n"
//usage: " Mem: 257628 248724 8904 59644 93124\n"
//usage: " Swap: 128516 8404 120112\n"
//usage: "Total: 386144 257128 129016\n"
//procps-ng 3.3.15:
// -b, --bytes show output in bytes
// --kilo show output in kilobytes
// --mega show output in megabytes
// --giga show output in gigabytes
// --tera show output in terabytes
// --peta show output in petabytes
// -k, --kibi show output in kibibytes
// -m, --mebi show output in mebibytes
// -g, --gibi show output in gibibytes
// --tebi show output in tebibytes
// --pebi show output in pebibytes
// -h, --human show human-readable output
// --si use powers of 1000 not 1024
// -l, --lohi show detailed low and high memory statistics
// -t, --total show total for RAM + swap
// -s N, --seconds N repeat printing every N seconds
// -c N, --count N repeat printing N times, then exit
// -w, --wide wide output
//
//NB: if we implement -s or -c, need to stop being NOFORK!
#include "libbb.h"
#ifdef __linux__
# include <sys/sysinfo.h>
#endif
struct globals {
unsigned mem_unit;
#if ENABLE_DESKTOP
unsigned unit;
# define G_unit g->unit
#else
# define G_unit (1 << 10)
#endif
unsigned long cached_kb, available_kb, reclaimable_kb;
};
/* Because of NOFORK, "globals" are not in global data */
static const char *scale(struct globals *g, unsigned long d)
{
/* Display (size * block_size) with one decimal digit.
* If display_unit == 0, show value no bigger than 1024 with suffix (K,M,G...),
* else divide by display_unit and do not use suffix.
* Returns "auto pointer" */
return make_human_readable_str(d, g->mem_unit, G_unit);
}
/* NOINLINE reduces main() stack usage, which makes code smaller (on x86 at least) */
static NOINLINE unsigned int parse_meminfo(struct globals *g)
{
char buf[60]; /* actual lines we expect are ~30 chars or less */
FILE *fp;
int seen_cached_and_available_and_reclaimable;
fp = xfopen_for_read("/proc/meminfo");
g->cached_kb = g->available_kb = g->reclaimable_kb = 0;
seen_cached_and_available_and_reclaimable = 3;
while (fgets(buf, sizeof(buf), fp)) {
if (sscanf(buf, "Cached: %lu %*s\n", &g->cached_kb) == 1)
if (--seen_cached_and_available_and_reclaimable == 0)
break;
if (sscanf(buf, "MemAvailable: %lu %*s\n", &g->available_kb) == 1)
if (--seen_cached_and_available_and_reclaimable == 0)
break;
if (sscanf(buf, "SReclaimable: %lu %*s\n", &g->reclaimable_kb) == 1)
if (--seen_cached_and_available_and_reclaimable == 0)
break;
}
/* Have to close because of NOFORK */
fclose(fp);
return seen_cached_and_available_and_reclaimable == 0;
}
int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
{
struct globals G;
struct sysinfo info;
unsigned long long cached, cached_plus_free, available;
int seen_available;
#if ENABLE_DESKTOP
G.unit = 1 << 10;
if (argv[1] && argv[1][0] == '-') {
switch (argv[1][1]) {
case 'b':
G.unit = 1;
break;
case 'k': /* 2^10 */
/* G.unit = 1 << 10; - already is */
break;
case 'm': /* 2^20 */
G.unit = 1 << 20;
break;
case 'g': /* 2^30 */
G.unit = 1 << 30;
break;
// case 't':
// -- WRONG, -t is not "terabytes" in procps-ng, it's --total
// G.unit = 1 << 40;
// break;
case 'h':
G.unit = 0; /* human readable */
break;
default:
bb_show_usage();
}
}
#endif
printf(" %12s%12s%12s%12s%12s%12s\n"
"Mem: ",
"total",
"used",
"free",
"shared", "buff/cache", "available" /* swap and total don't have these columns */
);
sysinfo(&info);
/* Extract cached and memavailable from /proc/meminfo and convert to mem_units */
seen_available = parse_meminfo(&G);
G.mem_unit = (info.mem_unit ? info.mem_unit : 1); /* kernels < 2.4.x return mem_unit==0, so cope */
available = ((unsigned long long) G.available_kb * 1024) / G.mem_unit;
cached = ((unsigned long long) G.cached_kb * 1024) / G.mem_unit;
cached += info.bufferram;
cached += ((unsigned long long) G.reclaimable_kb * 1024) / G.mem_unit;
cached_plus_free = cached + info.freeram;
printf("%12s%12s%12s",
scale(&G, info.totalram), //total
scale(&G, info.totalram - cached_plus_free), //used
scale(&G, info.freeram) //free
);
/* using two printf's: only 4 auto strings are supported, we need 6 */
printf("%12s%12s%12s\n",
scale(&G, info.sharedram), //shared
scale(&G, cached), //buff/cache
scale(&G, available) //available
);
/* On kernels < 3.14, MemAvailable is not provided.
* Show alternate, more meaningful busy/free numbers by counting
* buffer cache as free memory. */
if (!seen_available) {
printf("-/+ buffers/cache: ");
printf("%12s%12s%12s\n" + 4,
scale(&G, info.totalram - cached_plus_free), //used
scale(&G, cached_plus_free) //free
);
}
#if BB_MMU
printf("Swap: ");
printf("%12s%12s%12s\n",
scale(&G, info.totalswap), //total
scale(&G, info.totalswap - info.freeswap), //used
scale(&G, info.freeswap) //free
);
#endif
return EXIT_SUCCESS;
}
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