procps/free.c

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/*
* free.c - free(1)
* procps-ng utility to display free memory information
*
* Mostly new, Sami Kerola <kerolasa@iki.fi> 15 Apr 2011
* All new, Robert Love <rml@tech9.net> 18 Nov 2002
* Original by Brian Edmonds and Rafal Maszkowski 14 Dec 1992
*
* This program is licensed under the GNU Library General Public License, v2
*
* Copyright 2003 Robert Love
* Copyright 2004 Albert Cahalan
*/
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#include "proc/sysinfo.h"
#include "proc/version.h"
#include <errno.h>
#include <err.h>
#include <limits.h>
#include <ctype.h>
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#include <getopt.h>
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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#ifndef SIZE_MAX
#define SIZE_MAX 32
#endif
#define FREE_HUMANREADABLE (1 << 1)
#define FREE_LOHI (1 << 2)
#define FREE_OLDFMT (1 << 3)
#define FREE_TOTAL (1 << 4)
#define FREE_SI (1 << 5)
#define FREE_REPEAT (1 << 6)
#define FREE_REPEATCOUNT (1 << 7)
struct commandline_arguments {
int exponent; /* demanded in kilos, magas... */
float repeat_interval; /* delay in seconds */
int repeat_counter; /* number of repeats */
};
/* function prototypes */
static void usage(FILE * out);
double power(unsigned int base, unsigned int expo);
static const char *scale_size(unsigned long size, int flags, struct commandline_arguments args);
static void __attribute__ ((__noreturn__))
usage(FILE * out)
{
fprintf(out, "\nUsage: %s [options]\n" "\nOptions:\n", program_invocation_short_name);
fprintf(out,
" -b, --bytes show output in bytes\n"
" -k, --kilo show output in kilobytes\n"
" -m, --mega show output in megabytes\n"
" -g, --giga show output in gigabytes\n"
" --tera show output in terabytes\n"
" -h, --human show human readable output\n"
" --si use powers of 1000 not 1024\n"
" -l, --lohi show detailed low and high memory statistics\n"
" -o, --old use old format (no -/+buffers/cache line)\n"
" -t, --total show total for RAM + swap\n"
" -s N, --seconds N repeat printing every N seconds\n"
" -c N, --count N repeat printing N times\n");
fprintf(out,
" --help display this help text\n"
" -V, --version display version information and exit\n");
fprintf(out, "\nFor more information see free(1).\n");
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
double power(unsigned int base, unsigned int expo)
{
return (expo == 0) ? 1 : base * power(base, expo - 1);
}
/* idea of this function is copied from top size scaling */
static const char *scale_size(unsigned long size, int flags, struct commandline_arguments args)
{
static char nextup[] = { 'B', 'K', 'M', 'G', 'T', 0 };
static char buf[SIZE_MAX];
int i;
char *up;
float base;
if (flags & FREE_SI)
base = 1000.0;
else
base = 1024.0;
/* default output */
if (args.exponent == 0 && !(flags & FREE_HUMANREADABLE)) {
snprintf(buf, sizeof(buf), "%ld", size);
return buf;
}
if (!(flags & FREE_HUMANREADABLE)) {
if (args.exponent == 1) {
/* in bytes, which can not be in SI */
snprintf(buf, sizeof(buf), "%ld", (long int)(size * 1024));
return buf;
}
if (args.exponent == 2) {
if (!(flags & FREE_SI))
snprintf(buf, sizeof(buf), "%ld", size);
else
snprintf(buf, sizeof(buf), "%ld", (long int)(size / 0.9765625));
return buf;
}
if (args.exponent > 2) {
/* In desired scale. */
snprintf(buf, sizeof(buf), "%ld",
(long int)(size / power(base, args.exponent - 2))
);
return buf;
}
}
/* human readable output */
up = nextup;
for (i = 1; up[0] != '0'; i++, up++) {
switch (i) {
case 1:
if (4 >= snprintf(buf, sizeof(buf), "%ld%c", (long)size * 1024, *up))
return buf;
break;
case 2:
if (!(flags & FREE_SI)) {
if (4 >= snprintf(buf, sizeof(buf), "%ld%c", size, *up))
return buf;
} else {
if (4 >=
snprintf(buf, sizeof(buf), "%ld%c",
(long)(size / 0.9765625), *up))
return buf;
}
break;
case 3:
case 4:
case 5:
if (4 >=
snprintf(buf, sizeof(buf), "%.1f%c",
(float)(size / power(base, i - 2)), *up))
return buf;
if (4 >=
snprintf(buf, sizeof(buf), "%ld%c",
(long)(size / power(base, i - 2)), *up))
return buf;
break;
case 6:
break;
}
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}
/*
* On system where there is more than petabyte of memory or swap the
* output does not fit to column. For incoming few years this should
* not be a big problem (wrote at Apr, 2011).
*/
return buf;
}
int main(int argc, char **argv)
{
int c, flags = 0;
char *endptr;
struct commandline_arguments args;
/*
* For long options that have no equivalent short option, use a
* non-character as a pseudo short option, starting with CHAR_MAX + 1.
*/
enum {
SI_OPTION = CHAR_MAX + 1,
TERA_OPTION,
HELP_OPTION
};
static const struct option longopts[] = {
{ "bytes", no_argument, NULL, 'b' },
{ "kilo", no_argument, NULL, 'k' },
{ "mega", no_argument, NULL, 'm' },
{ "giga", no_argument, NULL, 'g' },
{ "tera", no_argument, NULL, TERA_OPTION },
{ "human", no_argument, NULL, 'h' },
{ "si", no_argument, NULL, SI_OPTION },
{ "lohi", no_argument, NULL, 'l' },
{ "old", no_argument, NULL, 'o' },
{ "total", no_argument, NULL, 't' },
{ "seconds", required_argument, NULL, 's' },
{ "count", required_argument, NULL, 'c' },
{ "help", no_argument, NULL, HELP_OPTION },
{ "version", no_argument, NULL, 'V' },
{ NULL, 0, NULL, 0 }
};
/* defaults to old format */
args.exponent = 0;
args.repeat_interval = 1000000;
args.repeat_counter = 0;
while ((c = getopt_long(argc, argv, "bkmghlotc:s:V", longopts, NULL)) != -1)
switch (c) {
case 'b':
args.exponent = 1;
break;
case 'k':
args.exponent = 2;
break;
case 'm':
args.exponent = 3;
break;
case 'g':
args.exponent = 4;
break;
case TERA_OPTION:
args.exponent = 5;
break;
case 'h':
flags |= FREE_HUMANREADABLE;
break;
case SI_OPTION:
flags |= FREE_SI;
break;
case 'l':
flags |= FREE_LOHI;
break;
case 'o':
flags |= FREE_OLDFMT;
break;
case 't':
flags |= FREE_TOTAL;
break;
case 's':
flags |= FREE_REPEAT;
args.repeat_interval = (1000000 * strtof(optarg, &endptr));
if (errno || optarg == endptr || (endptr && *endptr))
errx(EXIT_FAILURE, "seconds argument `%s' failed", optarg);
if (args.repeat_interval < 1)
errx(EXIT_FAILURE,
"seconds argument `%s' is not positive number", optarg);
break;
case 'c':
flags |= FREE_REPEAT;
flags |= FREE_REPEATCOUNT;
args.repeat_counter = strtoul(optarg, &endptr, 10);
if (errno || optarg == endptr || (endptr && *endptr))
errx(EXIT_FAILURE, "count argument `%s' failed", optarg);
break;
case HELP_OPTION:
usage(stdout);
case 'V':
display_version();
exit(EXIT_SUCCESS);
default:
usage(stderr);
}
do {
meminfo();
printf
(" total used free shared buffers cached\n");
printf("%-7s", "Mem:");
printf(" %10s", scale_size(kb_main_total, flags, args));
printf(" %10s", scale_size(kb_main_used, flags, args));
printf(" %10s", scale_size(kb_main_free, flags, args));
printf(" %10s", scale_size(kb_main_shared, flags, args));
printf(" %10s", scale_size(kb_main_buffers, flags, args));
printf(" %10s", scale_size(kb_main_cached, flags, args));
printf("\n");
/*
* Print low vs. high information, if the user requested it.
* Note we check if low_total == 0: if so, then this kernel
* does not export the low and high stats. Note we still want
* to print the high info, even if it is zero.
*/
if (flags & FREE_LOHI) {
printf("%-7s", "Low:");
printf(" %10s", scale_size(kb_low_total, flags, args));
printf(" %10s", scale_size(kb_low_total - kb_low_free, flags, args));
printf(" %10s", scale_size(kb_low_free, flags, args));
printf("\n");
printf("%-7s", "High:");
printf(" %10s", scale_size(kb_high_total, flags, args));
printf(" %10s", scale_size(kb_high_total - kb_high_free, flags, args));
printf(" %10s", scale_size(kb_high_free, flags, args));
printf("\n");
}
if (!(flags & FREE_OLDFMT)) {
unsigned KLONG buffers_plus_cached = kb_main_buffers + kb_main_cached;
printf("-/+ buffers/cache:");
printf(" %10s",
scale_size(kb_main_used - buffers_plus_cached, flags, args));
printf(" %10s",
scale_size(kb_main_free + buffers_plus_cached, flags, args));
printf("\n");
}
printf("%-7s", "Swap:");
printf(" %10s", scale_size(kb_swap_total, flags, args));
printf(" %10s", scale_size(kb_swap_used, flags, args));
printf(" %10s", scale_size(kb_swap_free, flags, args));
printf("\n");
if (flags & FREE_TOTAL) {
printf("%-7s", "Total:");
printf(" %10s", scale_size(kb_main_total + kb_swap_total, flags, args));
printf(" %10s", scale_size(kb_main_used + kb_swap_used, flags, args));
printf(" %10s", scale_size(kb_main_free + kb_swap_free, flags, args));
printf("\n");
}
fflush(stdout);
if (flags & FREE_REPEATCOUNT) {
args.repeat_counter--;
if (args.repeat_counter < 1)
exit(EXIT_SUCCESS);
}
if (flags & FREE_REPEAT) {
printf("\n");
usleep(args.repeat_interval);
}
} while ((flags & FREE_REPEAT));
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exit(EXIT_SUCCESS);
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}