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/* GNU's users.
Copyright (C) 1992-2004 Free Software Foundation, Inc.
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, 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. */
/* Written by jla; revised by djm */
#include <config.h>
#include <getopt.h>
#include <stdio.h>
#include <sys/types.h>
#include "system.h"
#include "error.h"
#include "long-options.h"
#include "quote.h"
#include "readutmp.h"
/* The official name of this program (e.g., no `g' prefix). */
#define PROGRAM_NAME "users"
#define AUTHORS "Joseph Arceneaux", "David MacKenzie"
/* The name this program was run with. */
char *program_name;
static struct option const longopts[] =
{
{NULL, 0, NULL, 0}
};
static int
userid_compare (const void *v_a, const void *v_b)
{
char **a = (char **) v_a;
char **b = (char **) v_b;
return strcmp (*a, *b);
}
static void
list_entries_users (size_t n, const STRUCT_UTMP *this)
{
char **u = xnmalloc (n, sizeof *u);
size_t i;
size_t n_entries = 0;
while (n--)
{
if (UT_USER (this) [0]
#ifdef USER_PROCESS
&& this->ut_type == USER_PROCESS
#endif
)
{
char *trimmed_name;
trimmed_name = extract_trimmed_name (this);
u[n_entries] = trimmed_name;
++n_entries;
}
this++;
}
qsort (u, n_entries, sizeof (u[0]), userid_compare);
for (i = 0; i < n_entries; i++)
{
char c = (i < n_entries - 1 ? ' ' : '\n');
fputs (u[i], stdout);
putchar (c);
}
for (i = 0; i < n_entries; i++)
free (u[i]);
free (u);
}
/* Display a list of users on the system, according to utmp file FILENAME. */
static void
users (const char *filename)
{
size_t n_users;
STRUCT_UTMP *utmp_buf;
if (read_utmp (filename, &n_users, &utmp_buf) != 0)
error (EXIT_FAILURE, errno, "%s", filename);
list_entries_users (n_users, utmp_buf);
free (utmp_buf);
}
void
usage (int status)
{
if (status != EXIT_SUCCESS)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("Usage: %s [OPTION]... [ FILE ]\n"), program_name);
printf (_("\
Output who is currently logged in according to FILE.\n\
If FILE is not specified, use %s. %s as FILE is common.\n\
\n\
"),
UTMP_FILE, WTMP_FILE);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
}
exit (status);
}
int
main (int argc, char **argv)
{
int optc;
initialize_main (&argc, &argv);
program_name = argv[0];
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
usage, AUTHORS, (char const *) NULL);
while ((optc = getopt_long (argc, argv, "", longopts, NULL)) != -1)
{
switch (optc)
{
case 0:
break;
default:
usage (EXIT_FAILURE);
}
}
switch (argc - optind)
{
case 0: /* users */
users (UTMP_FILE);
break;
case 1: /* users <utmp file> */
users (argv[optind]);
break;
default: /* lose */
error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
usage (EXIT_FAILURE);
}
exit (EXIT_SUCCESS);
}
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