1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2002 Tim J. Robbins.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/param.h>
30#include <sys/types.h>
31#include <sys/ioctl.h>
32#include <sys/stat.h>
33
34#include <err.h>
35#include <errno.h>
36#include <langinfo.h>
37#include <limits.h>
38#include <locale.h>
39#include <paths.h>
40#include <pwd.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <time.h>
45#include <timeconv.h>
46#include <unistd.h>
47#include <utmpx.h>
48
49static void	heading(void);
50static void	process_utmp(void);
51static void	quick(void);
52static void	row(const struct utmpx *);
53static int	ttywidth(void);
54static void	usage(void);
55static void	whoami(void);
56
57static int	Hflag;			/* Write column headings */
58static int	aflag;			/* Print all entries */
59static int	bflag;			/* Show date of the last reboot */
60static int	mflag;			/* Show info about current terminal */
61static int	qflag;			/* "Quick" mode */
62static int	sflag;			/* Show name, line, time */
63static int	Tflag;			/* Show terminal state */
64static int	uflag;			/* Show idle time */
65
66int
67main(int argc, char *argv[])
68{
69	int ch;
70
71	setlocale(LC_TIME, "");
72
73	while ((ch = getopt(argc, argv, "HTabmqsu")) != -1) {
74		switch (ch) {
75		case 'H':		/* Write column headings */
76			Hflag = 1;
77			break;
78		case 'T':		/* Show terminal state */
79			Tflag = 1;
80			break;
81		case 'a':		/* Same as -bdlprtTu */
82			aflag = bflag = Tflag = uflag = 1;
83			break;
84		case 'b':		/* Show date of the last reboot */
85			bflag = 1;
86			break;
87		case 'm':		/* Show info about current terminal */
88			mflag = 1;
89			break;
90		case 'q':		/* "Quick" mode */
91			qflag = 1;
92			break;
93		case 's':		/* Show name, line, time */
94			sflag = 1;
95			break;
96		case 'u':		/* Show idle time */
97			uflag = 1;
98			break;
99		default:
100			usage();
101			/*NOTREACHED*/
102		}
103	}
104	argc -= optind;
105	argv += optind;
106
107	if (argc >= 2 && strcmp(argv[0], "am") == 0 &&
108	    (strcmp(argv[1], "i") == 0 || strcmp(argv[1], "I") == 0)) {
109		/* "who am i" or "who am I", equivalent to -m */
110		mflag = 1;
111		argc -= 2;
112		argv += 2;
113	}
114	if (argc > 1)
115		usage();
116
117	if (*argv != NULL) {
118		if (setutxdb(UTXDB_ACTIVE, *argv) != 0)
119			err(1, "%s", *argv);
120	}
121
122	if (qflag)
123		quick();
124	else {
125		if (sflag)
126			Tflag = uflag = 0;
127		if (Hflag)
128			heading();
129		if (mflag)
130			whoami();
131		else
132			process_utmp();
133	}
134
135	endutxent();
136
137	exit(0);
138}
139
140static void
141usage(void)
142{
143
144	fprintf(stderr, "usage: who [-abHmqsTu] [am I] [file]\n");
145	exit(1);
146}
147
148static void
149heading(void)
150{
151
152	printf("%-16s ", "NAME");
153	if (Tflag)
154		printf("S ");
155	printf("%-12s %-12s ", "LINE", "TIME");
156	if (uflag)
157		printf("IDLE  ");
158	printf("%-16s\n", "FROM");
159}
160
161static void
162row(const struct utmpx *ut)
163{
164	char buf[80], tty[PATH_MAX];
165	struct stat sb;
166	time_t idle, t;
167	static int d_first = -1;
168	struct tm *tm;
169	char state;
170
171	if (d_first < 0)
172		d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
173
174	state = '?';
175	idle = 0;
176	if (Tflag || uflag) {
177		snprintf(tty, sizeof(tty), "%s%s", _PATH_DEV, ut->ut_line);
178		if (stat(tty, &sb) == 0) {
179			state = sb.st_mode & (S_IWOTH|S_IWGRP) ?
180			    '+' : '-';
181			idle = time(NULL) - sb.st_mtime;
182		}
183	}
184
185	printf("%-16s ", ut->ut_user);
186	if (Tflag)
187		printf("%c ", state);
188	if (ut->ut_type == BOOT_TIME)
189		printf("%-12s ", "system boot");
190	else
191		printf("%-12s ", ut->ut_line);
192	t = ut->ut_tv.tv_sec;
193	tm = localtime(&t);
194	strftime(buf, sizeof(buf), d_first ? "%e %b %R" : "%b %e %R", tm);
195	printf("%-*s ", 12, buf);
196	if (uflag) {
197		if (idle < 60)
198			printf("  .   ");
199		else if (idle < 24 * 60 * 60)
200			printf("%02d:%02d ", (int)(idle / 60 / 60),
201			    (int)(idle / 60 % 60));
202		else
203			printf(" old  ");
204	}
205	if (*ut->ut_host != '\0')
206		printf("(%s)", ut->ut_host);
207	putchar('\n');
208}
209
210static int
211ttystat(char *line)
212{
213	struct stat sb;
214	char ttybuf[MAXPATHLEN];
215
216	if (line == NULL)
217		return (0);
218	(void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
219	if (stat(ttybuf, &sb) == 0) {
220		return (0);
221	} else
222		return (-1);
223}
224
225static void
226process_utmp(void)
227{
228	struct utmpx *utx;
229
230	while ((utx = getutxent()) != NULL) {
231		if ((aflag || !bflag) && utx->ut_type == USER_PROCESS) {
232			if (ttystat(utx->ut_line) == 0)
233				row(utx);
234		} else if (bflag && utx->ut_type == BOOT_TIME)
235				row(utx);
236	}
237}
238
239static void
240quick(void)
241{
242	struct utmpx *utx;
243	int col, ncols, num;
244
245	ncols = ttywidth();
246	col = num = 0;
247	while ((utx = getutxent()) != NULL) {
248		if (utx->ut_type != USER_PROCESS)
249			continue;
250		printf("%-16s", utx->ut_user);
251		if (++col < ncols / (16 + 1))
252			putchar(' ');
253		else {
254			col = 0;
255			putchar('\n');
256		}
257		num++;
258	}
259	if (col != 0)
260		putchar('\n');
261
262	printf("# users = %d\n", num);
263}
264
265static void
266whoami(void)
267{
268	struct utmpx ut, *utx;
269	struct passwd *pwd;
270	const char *name, *tty;
271
272	if ((tty = ttyname(STDIN_FILENO)) == NULL)
273		tty = "tty??";
274	else if (strncmp(tty, _PATH_DEV, sizeof _PATH_DEV - 1) == 0)
275		tty += sizeof _PATH_DEV - 1;
276	strlcpy(ut.ut_line, tty, sizeof ut.ut_line);
277
278	/* Search utmp for our tty, dump first matching record. */
279	if ((utx = getutxline(&ut)) != NULL && utx->ut_type == USER_PROCESS) {
280		row(utx);
281		return;
282	}
283
284	/* Not found; fill the utmp structure with the information we have. */
285	memset(&ut, 0, sizeof(ut));
286	if ((pwd = getpwuid(getuid())) != NULL)
287		name = pwd->pw_name;
288	else
289		name = "?";
290	strlcpy(ut.ut_user, name, sizeof ut.ut_user);
291	gettimeofday(&ut.ut_tv, NULL);
292	row(&ut);
293}
294
295static int
296ttywidth(void)
297{
298	struct winsize ws;
299	long width;
300	char *cols, *ep;
301
302	if ((cols = getenv("COLUMNS")) != NULL && *cols != '\0') {
303		errno = 0;
304		width = strtol(cols, &ep, 10);
305		if (errno || width <= 0 || width > INT_MAX || ep == cols ||
306		    *ep != '\0')
307			warnx("invalid COLUMNS environment variable ignored");
308		else
309			return (width);
310	}
311	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1)
312		return (ws.ws_col);
313
314	return (80);
315}
316