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