/*
* Mini free implementation for busybox
*
- * Copyright (C) 1999,2000,2001 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * 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 (2.4 kb)"
+//config: default y
+//config: select PLATFORM_LINUX #sysinfo()
+//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+//config: The shared memory column should be ignored; it is obsolete.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-$(CONFIG_FREE) += free.o
+
+//usage:#define free_trivial_usage
+//usage: "" IF_DESKTOP("[-b/k/m/g]")
+//usage:#define free_full_usage "\n\n"
+//usage: "Display the amount of free and used system memory"
+//usage:
+//usage:#define free_example_usage
+//usage: "$ 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"
-#include "busybox.h"
-#include <stdio.h>
-#include <errno.h>
-#include <stdlib.h>
+#include "libbb.h"
+#ifdef __linux__
+# include <sys/sysinfo.h>
+#endif
-extern int free_main(int argc, char **argv)
+struct globals {
+ unsigned mem_unit;
+#if ENABLE_DESKTOP
+ uint8_t unit_steps;
+# define G_unit_steps g->unit_steps
+#else
+# define G_unit_steps 10
+#endif
+};
+/* Because of NOFORK, "globals" are not in global data */
+
+static unsigned long long scale(struct globals *g, unsigned long d)
{
- struct sysinfo info;
- sysinfo(&info);
+ return ((unsigned long long)d * g->mem_unit) >> G_unit_steps;
+}
- /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
- if (info.mem_unit==0) {
- info.mem_unit=1;
+/* NOINLINE reduces main() stack usage, which makes code smaller (on x86 at least) */
+static NOINLINE unsigned int parse_meminfo(unsigned long *cached_kb, unsigned long *available_kb)
+{
+ char buf[60]; /* actual lines we expect are ~30 chars or less */
+ FILE *fp;
+ int seen_cached_and_available;
+
+ fp = xfopen_for_read("/proc/meminfo");
+ *cached_kb = *available_kb = 0;
+ seen_cached_and_available = 2;
+ while (fgets(buf, sizeof(buf), fp)) {
+ if (sscanf(buf, "Cached: %lu %*s\n", cached_kb) == 1)
+ if (--seen_cached_and_available == 0)
+ break;
+ if (sscanf(buf, "MemAvailable: %lu %*s\n", available_kb) == 1)
+ if (--seen_cached_and_available == 0)
+ break;
}
- info.mem_unit*=1024;
-
- /* TODO: Make all this stuff not overflow when mem >= 4 Gib */
- info.totalram/=info.mem_unit;
- info.freeram/=info.mem_unit;
- info.totalswap/=info.mem_unit;
- info.freeswap/=info.mem_unit;
- info.sharedram/=info.mem_unit;
- info.bufferram/=info.mem_unit;
+ /* Have to close because of NOFORK */
+ fclose(fp);
- if (argc > 1 && **(argv + 1) == '-')
- show_usage();
+ return seen_cached_and_available == 0;
+}
- printf("%6s%13s%13s%13s%13s%13s\n", "", "total", "used", "free",
- "shared", "buffers");
+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;
+ unsigned long cached_kb, available_kb;
+ int seen_available;
- printf("%6s%13ld%13ld%13ld%13ld%13ld\n", "Mem:", info.totalram,
- info.totalram-info.freeram, info.freeram,
- info.sharedram, info.bufferram);
+#if ENABLE_DESKTOP
+ G.unit_steps = 10;
+ if (argv[1] && argv[1][0] == '-') {
+ switch (argv[1][1]) {
+ case 'b':
+ G.unit_steps = 0;
+ break;
+ case 'k': /* 2^10 */
+ /* G.unit_steps = 10; - already is */
+ break;
+ case 'm': /* 2^(2*10) */
+ G.unit_steps = 20;
+ break;
+ case 'g': /* 2^(3*10) */
+ G.unit_steps = 30;
+ 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 */
+ );
- printf("%6s%13ld%13ld%13ld\n", "Swap:", info.totalswap,
- info.totalswap-info.freeswap, info.freeswap);
+ sysinfo(&info);
+ /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
+ G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
+ /* Extract cached and memavailable from /proc/meminfo and convert to mem_units */
+ seen_available = parse_meminfo(&cached_kb, &available_kb);
+ available = ((unsigned long long) available_kb * 1024) / G.mem_unit;
+ cached = ((unsigned long long) cached_kb * 1024) / G.mem_unit;
+ cached += info.bufferram;
+ cached_plus_free = cached + info.freeram;
+
+#define FIELDS_6 "%12llu%12llu%12llu%12llu%12llu%12llu\n"
+#define FIELDS_3 (FIELDS_6 + 3*6)
+#define FIELDS_2 (FIELDS_6 + 4*6)
- printf("%6s%13ld%13ld%13ld\n", "Total:", info.totalram+info.totalswap,
- (info.totalram-info.freeram)+(info.totalswap-info.freeswap),
- info.freeram+info.freeswap);
+ printf(FIELDS_6,
+ scale(&G, info.totalram), //total
+ scale(&G, info.totalram - cached_plus_free), //used
+ scale(&G, info.freeram), //free
+ 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(FIELDS_2,
+ scale(&G, info.totalram - cached_plus_free), //used
+ scale(&G, cached_plus_free) //free
+ );
+ }
+#if BB_MMU
+ printf("Swap: ");
+ printf(FIELDS_3,
+ scale(&G, info.totalswap), //total
+ scale(&G, info.totalswap - info.freeswap), //used
+ scale(&G, info.freeswap) //free
+ );
+#endif
return EXIT_SUCCESS;
}
-
-
projects / oweals / busybox.git / blobdiff