/* vi: set sw=4 ts=4: */ /* * Mini free implementation for busybox * * Copyright (C) 1999-2004 by Erik Andersen * * 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 //config: The shared memory column should be ignored; it is obsolete.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 #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; }