1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/* GNU's users.
Copyright (C) 1992-2018 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 3 of the License, 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, see <https://www.gnu.org/licenses/>. */
/* Written by jla; revised by djm */
#include <config.h>
#include <getopt.h>
#include <stdio.h>
#include <sys/types.h>
#include "system.h"
#include "die.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 \
proper_name ("Joseph Arceneaux"), \
proper_name ("David MacKenzie")
static struct option const long_options[] =
{
{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 (IS_USER_PROCESS (this))
{
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.
Use read_utmp OPTIONS to read FILENAME. */
static void
users (const char *filename, int options)
{
size_t n_users;
STRUCT_UTMP *utmp_buf;
if (read_utmp (filename, &n_users, &utmp_buf, options) != 0)
die (EXIT_FAILURE, errno, "%s", quotef (filename));
list_entries_users (n_users, utmp_buf);
free (utmp_buf);
}
void
usage (int status)
{
if (status != EXIT_SUCCESS)
emit_try_help ();
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);
emit_ancillary_info (PROGRAM_NAME);
}
exit (status);
}
int
main (int argc, char **argv)
{
initialize_main (&argc, &argv);
set_program_name (argv[0]);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
usage, AUTHORS, (char const *) NULL);
if (getopt_long (argc, argv, "", long_options, NULL) != -1)
usage (EXIT_FAILURE);
switch (argc - optind)
{
case 0: /* users */
users (UTMP_FILE, READ_UTMP_CHECK_PIDS);
break;
case 1: /* users <utmp file> */
users (argv[optind], 0);
break;
default: /* lose */
error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
usage (EXIT_FAILURE);
}
return EXIT_SUCCESS;
}
|