1 /* vi: set sw=4 ts=4: */
3 * Mini free implementation for busybox
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Licensed under GPLv2, see file LICENSE in this source tree.
10 //config: bool "free (2.4 kb)"
12 //config: select PLATFORM_LINUX #sysinfo()
14 //config: free displays the total amount of free and used physical and swap
15 //config: memory in the system, as well as the buffers used by the kernel.
16 //config: The shared memory column should be ignored; it is obsolete.
18 //applet:IF_FREE(APPLET_NOFORK(free, free, BB_DIR_USR_BIN, BB_SUID_DROP, free))
20 //kbuild:lib-$(CONFIG_FREE) += free.o
22 //usage:#define free_trivial_usage
23 //usage: "" IF_DESKTOP("[-b/k/m/g]")
24 //usage:#define free_full_usage "\n\n"
25 //usage: "Display the amount of free and used system memory"
27 //usage:#define free_example_usage
29 //usage: " total used free shared buffers\n"
30 //usage: " Mem: 257628 248724 8904 59644 93124\n"
31 //usage: " Swap: 128516 8404 120112\n"
32 //usage: "Total: 386144 257128 129016\n"
35 #include "common_bufsiz.h"
37 # include <sys/sysinfo.h>
44 # define G_unit_steps g->unit_steps
46 # define G_unit_steps 10
49 /* Because of NOFORK, "globals" are not in global data */
51 static unsigned long long scale(struct globals *g, unsigned long d)
53 return ((unsigned long long)d * g->mem_unit) >> G_unit_steps;
56 /* NOINLINE reduces main() stack usage, which makes code smaller (on x86 at least) */
57 static NOINLINE unsigned long parse_cached_kb(void)
59 char buf[60]; /* actual lines we expect are ~30 chars or less */
61 unsigned long cached = 0;
63 fp = xfopen_for_read("/proc/meminfo");
64 while (fgets(buf, sizeof(buf), fp) != NULL) {
65 if (sscanf(buf, "Cached: %lu %*s\n", &cached) == 1)
68 /* Have to close because of NOFORK */
74 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
75 int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
79 unsigned long long cached;
83 if (argv[1] && argv[1][0] == '-') {
89 /* G.unit_steps = 10; - already is */
91 case 'm': /* 2^(2*10) */
94 case 'g': /* 2^(3*10) */
102 printf(" %11s%11s%11s%11s%11s%11s\n"
107 "shared", "buffers", "cached" /* swap and total don't have these columns */
111 /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
112 G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
113 /* Extract cached from /proc/meminfo and convert to mem_units */
114 cached = ((unsigned long long) parse_cached_kb() * 1024) / G.mem_unit;
116 #define FIELDS_6 "%11llu%11llu%11llu%11llu%11llu%11llu\n"
117 #define FIELDS_3 (FIELDS_6 + 3*6)
118 #define FIELDS_2 (FIELDS_6 + 4*6)
121 scale(&G, info.totalram), //total
122 scale(&G, info.totalram - info.freeram), //used
123 scale(&G, info.freeram), //free
124 scale(&G, info.sharedram), //shared
125 scale(&G, info.bufferram), //buffers
126 scale(&G, cached) //cached
128 /* Show alternate, more meaningful busy/free numbers by counting
129 * buffer cache as free memory. */
130 printf("-/+ buffers/cache:");
131 cached += info.freeram;
132 cached += info.bufferram;
134 scale(&G, info.totalram - cached), //used
135 scale(&G, cached) //free
140 scale(&G, info.totalswap), //total
141 scale(&G, info.totalswap - info.freeswap), //used
142 scale(&G, info.freeswap) //free