procps/uptime.c
Craig Small bcb837b8c7 First cut at subset=pid proc mount handling
The procfs mount option subset=pid only shows the processes, not things
such as /proc/stat etc.

For certain programs, this should mean they still work, but have reduced
functionality. This is the first cut at some of them.

pgrep - Removed always loading uptime which we never used anyway. The
program now works fine unless we use --older. Add note in man page
stating it will silently fail.

ps - Load boot time and memory total only when required instead of
always. Changed the error messages to something the user actually
cares about "can't get system boot time" vs "create a structure".
Works for most fields except starts and percent memory.

uptime - Give more useful error messages if uptime not available.

vmstat - move header generation after testing for required proc
files, makes the default output more consistent with the rest
of the options.

References:
 procps-ng/procps#227
 https://www.kernel.org/doc/html/latest/filesystems/proc.html#chapter-4-configuring-procfs
 6814ef2d99

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2021-12-16 20:36:00 +11:00

124 lines
3.6 KiB
C

/*
* uptime.c - display system uptime
* Copyright (C) 2012-2015 Craig Small <csmall@dropbear.xyz>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <getopt.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <sys/time.h>
#include "c.h"
#include "fileutils.h"
#include "nls.h"
#include <proc/misc.h>
static void print_uptime_since()
{
double now, uptime_secs, idle_secs;
time_t up_since_secs;
struct tm *up_since;
struct timeval tim;
/* Get the current time and convert it to a double */
if (gettimeofday(&tim, NULL) != 0)
xerr(EXIT_FAILURE, "gettimeofday");
now = tim.tv_sec + (tim.tv_usec / 1000000.0);
/* Get the uptime and calculate when that was */
if (procps_uptime(&uptime_secs, &idle_secs) < 0)
xerr(EXIT_FAILURE, _("Cannot get system uptime"));
up_since_secs = (time_t) ((now - uptime_secs) + 0.5);
/* Show this */
if ((up_since = localtime(&up_since_secs)) == NULL)
xerrx(EXIT_FAILURE, "localtime");
printf("%04d-%02d-%02d %02d:%02d:%02d\n",
up_since->tm_year + 1900, up_since->tm_mon + 1, up_since->tm_mday,
up_since->tm_hour, up_since->tm_min, up_since->tm_sec);
}
static void __attribute__ ((__noreturn__)) usage(FILE * out)
{
fputs(USAGE_HEADER, out);
fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
fputs(USAGE_OPTIONS, out);
fputs(_(" -p, --pretty show uptime in pretty format\n"), out);
fputs(USAGE_HELP, out);
fputs(_(" -s, --since system up since\n"), out);
fputs(USAGE_VERSION, out);
fprintf(out, USAGE_MAN_TAIL("uptime(1)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
int main(int argc, char **argv)
{
int c, p = 0;
char *uptime_str;
static const struct option longopts[] = {
{"pretty", no_argument, NULL, 'p'},
{"help", no_argument, NULL, 'h'},
{"since", no_argument, NULL, 's'},
{"version", no_argument, NULL, 'V'},
{NULL, 0, NULL, 0}
};
#ifdef HAVE_PROGRAM_INVOCATION_NAME
program_invocation_name = program_invocation_short_name;
#endif
setlocale (LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
while ((c = getopt_long(argc, argv, "phsV", longopts, NULL)) != -1)
switch (c) {
case 'p':
p = 1;
break;
case 'h':
usage(stdout);
case 's':
print_uptime_since();
return EXIT_SUCCESS;
case 'V':
printf(PROCPS_NG_VERSION);
return EXIT_SUCCESS;
default:
usage(stderr);
}
if (optind != argc)
usage(stderr);
if (p)
uptime_str = procps_uptime_sprint_short();
else
uptime_str = procps_uptime_sprint();
if (!uptime_str || uptime_str[0] == '\0')
xerr(EXIT_FAILURE, _("Cannot get system uptime"));
printf("%s\n", uptime_str);
return EXIT_SUCCESS;
}