xref: /dragonfly/usr.bin/who/who.c (revision 611395e5)
1 /*-
2  * Copyright (c) 2002 Tim J. Robbins.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD: src/usr.bin/who/who.c,v 1.9.2.4 2002/12/21 00:44:58 tjr Exp $
27  * $DragonFly: src/usr.bin/who/who.c,v 1.5 2004/10/29 17:09:09 liamfoy Exp $
28  */
29 
30 #include <sys/types.h>
31 #include <sys/ioctl.h>
32 #include <sys/stat.h>
33 #include <sys/sysctl.h>
34 
35 #include <err.h>
36 #include <errno.h>
37 #include <langinfo.h>
38 #include <limits.h>
39 #include <locale.h>
40 #include <paths.h>
41 #include <pwd.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <time.h>
46 #include <unistd.h>
47 #include <utmp.h>
48 
49 static void 	print_boottime(void);
50 static void	heading(void);
51 static void	process_utmp(FILE *);
52 static void	quick(FILE *);
53 static void	row(struct utmp *);
54 static int	ttywidth(void);
55 static void	usage(void);
56 static void	whoami(FILE *);
57 
58 static int 	bflag;			/* Show date and time of last reboot */
59 static int	Hflag;			/* Write column headings */
60 static int	mflag;			/* Show info about current terminal */
61 static int	qflag;			/* "Quick" mode */
62 static int	sflag;			/* Show name, line, time */
63 static int	Tflag;			/* Show terminal state */
64 static int	uflag;			/* Show idle time */
65 
66 int
67 main(int argc, char **argv)
68 {
69 	int ch;
70 	const char *file;
71 	FILE *fp;
72 
73 	setlocale(LC_TIME, "");
74 
75 	while ((ch = getopt(argc, argv, "HTbmqsu")) != -1) {
76 		switch (ch) {
77 		case 'H':		/* Write column headings */
78 			Hflag = 1;
79 			break;
80 		case 'T':		/* Show terminal state */
81 			Tflag = 1;
82 			break;
83 		case 'b':		/* Show time and date since last boot */
84 			bflag = 1;
85 			break;
86 		case 'm':		/* Show info about current terminal */
87 			mflag = 1;
88 			break;
89 		case 'q':		/* "Quick" mode */
90 			qflag = 1;
91 			break;
92 		case 's':		/* Show name, line, time */
93 			sflag = 1;
94 			break;
95 		case 'u':		/* Show idle time */
96 			uflag = 1;
97 			break;
98 		default:
99 			usage();
100 			/*NOTREACHED*/
101 		}
102 	}
103 	argc -= optind;
104 	argv += optind;
105 
106 	if (argc >= 2 && strcmp(argv[0], "am") == 0 &&
107 	    (strcmp(argv[1], "i") == 0 || strcmp(argv[1], "I") == 0)) {
108 		/* "who am i" or "who am I", equivalent to -m */
109 		mflag = 1;
110 		argc -= 2;
111 		argv += 2;
112 	}
113 	if (argc > 1)
114 		usage();
115 
116 	if (*argv != NULL)
117 		file = *argv;
118 	else
119 		file = _PATH_UTMP;
120 	if ((fp = fopen(file, "r")) == NULL)
121 		err(1, "%s", file);
122 
123 	if (qflag)
124 		quick(fp);
125 	else {
126 		if (sflag)
127 			Tflag = uflag = 0;
128 		if (bflag)
129 			print_boottime();
130 		if (Hflag)
131 			heading();
132 		if (mflag)
133 			whoami(fp);
134 		else
135 			process_utmp(fp);
136 	}
137 
138 	fclose(fp);
139 
140 	exit(0);
141 }
142 
143 static void
144 usage(void)
145 {
146 
147 	fprintf(stderr, "usage: who [-bHmqsTu] [am I] [file]\n");
148 	exit(1);
149 }
150 
151 static void
152 print_boottime(void) {
153 	struct timeval boottime;
154 	size_t size;
155 
156 	size = sizeof(boottime);
157 	if (sysctlbyname("kern.boottime", &boottime, &size, NULL, 0) != -1 &&
158 	    boottime.tv_sec != 0) {
159 		printf("%s", ctime(&boottime.tv_sec));
160 	}
161 }
162 
163 static void
164 heading(void)
165 {
166 
167 	printf("%-*s ", UT_NAMESIZE, "NAME");
168 	if (Tflag)
169 		printf("S ");
170 	printf("%-*s ", UT_LINESIZE, "LINE");
171 	printf("%-*s ", 12, "TIME");
172 	if (uflag)
173 		printf("IDLE  ");
174 	printf("%-*s", UT_HOSTSIZE, "FROM");
175 	putchar('\n');
176 }
177 
178 static void
179 row(struct utmp *ut)
180 {
181 	char buf[80], tty[sizeof(_PATH_DEV) + UT_LINESIZE];
182 	struct stat sb;
183 	time_t idle = NULL;
184 	static int d_first = -1;
185 	struct tm *tm;
186 	char state = NULL;
187 
188 	if (d_first < 0)
189 		d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
190 
191 	if (Tflag || uflag) {
192 		snprintf(tty, sizeof(tty), "%s%.*s", _PATH_DEV,
193 			UT_LINESIZE, ut->ut_line);
194 		state = '?';
195 		idle = 0;
196 		if (stat(tty, &sb) == 0) {
197 			state = sb.st_mode & (S_IWOTH|S_IWGRP) ?
198 			    '+' : '-';
199 			idle = time(NULL) - sb.st_mtime;
200 		} else {
201 			err(1, "Cannot open %s", tty);
202 		}
203 	}
204 
205 	printf("%-*.*s ", UT_NAMESIZE, UT_NAMESIZE, ut->ut_name);
206 	if (Tflag)
207 		printf("%c ", state);
208 	printf("%-*.*s ", UT_LINESIZE, UT_LINESIZE, ut->ut_line);
209 	tm = localtime(&ut->ut_time);
210 	strftime(buf, sizeof(buf), d_first ? "%e %b %R" : "%b %e %R", tm);
211 	printf("%-*s ", 12, buf);
212 	if (uflag) {
213 		if (idle < 60)
214 			printf("  .   ");
215 		else if (idle < 24 * 60 * 60)
216 			printf("%02d:%02d ", (int)(idle / 60 / 60),
217 			    (int)(idle / 60 % 60));
218 		else
219 			printf(" old  ");
220 	}
221 	if (*ut->ut_host != '\0')
222 		printf("(%.*s)", UT_HOSTSIZE, ut->ut_host);
223 	putchar('\n');
224 }
225 
226 static void
227 process_utmp(FILE *fp)
228 {
229 	struct utmp ut;
230 
231 	while (fread(&ut, sizeof(ut), 1, fp) == 1)
232 		if (*ut.ut_name != '\0')
233 			row(&ut);
234 }
235 
236 static void
237 quick(FILE *fp)
238 {
239 	struct utmp ut;
240 	int col, ncols, num;
241 
242 	ncols = ttywidth();
243 	col = num = 0;
244 	while (fread(&ut, sizeof(ut), 1, fp) == 1) {
245 		if (*ut.ut_name == '\0')
246 			continue;
247 		printf("%-*.*s", UT_NAMESIZE, UT_NAMESIZE, ut.ut_name);
248 		if (++col < ncols / (UT_NAMESIZE + 1))
249 			putchar(' ');
250 		else {
251 			col = 0;
252 			putchar('\n');
253 		}
254 		num++;
255 	}
256 	if (col != 0)
257 		putchar('\n');
258 
259 	printf("# users = %d\n", num);
260 }
261 
262 static void
263 whoami(FILE *fp)
264 {
265 	struct utmp ut;
266 	struct passwd *pwd;
267 	const char *name, *p, *tty;
268 
269 	if ((tty = ttyname(STDIN_FILENO)) == NULL)
270 		tty = "tty??";
271 	else if ((p = strrchr(tty, '/')) != NULL)
272 		tty = p + 1;
273 
274 	/* Search utmp for our tty, dump first matching record. */
275 	while (fread(&ut, sizeof(ut), 1, fp) == 1)
276 		if (*ut.ut_name != '\0' && strncmp(ut.ut_line, tty,
277 		    UT_LINESIZE) == 0) {
278 			row(&ut);
279 			return;
280 		}
281 
282 	/* Not found; fill the utmp structure with the information we have. */
283 	memset(&ut, 0, sizeof(ut));
284 	if ((pwd = getpwuid(getuid())) != NULL)
285 		name = pwd->pw_name;
286 	else
287 		name = "?";
288 	strncpy(ut.ut_name, name, UT_NAMESIZE);
289 	strncpy(ut.ut_line, tty, UT_LINESIZE);
290 	time(&ut.ut_time);
291 	row(&ut);
292 }
293 
294 static int
295 ttywidth(void)
296 {
297 	struct winsize ws;
298 	long width;
299 	char *cols, *ep;
300 
301 	if ((cols = getenv("COLUMNS")) != NULL && *cols != '\0') {
302 		errno = 0;
303 		width = strtol(cols, &ep, 10);
304 		if (errno || width <= 0 || width > INT_MAX || ep == cols ||
305 		    *ep != '\0')
306 			warnx("invalid COLUMNS environment variable ignored");
307 		else
308 			return (width);
309 	}
310 	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1)
311 		return (ws.ws_col);
312 
313 	return (80);
314 }
315