1/*-
2 * Copyright (c) 1980, 1991, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 * Portions copyright (c) 2007 Apple Inc.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32
33#ifndef __APPLE__
34__FBSDID("$FreeBSD: src/usr.bin/w/w.c,v 1.58 2005/06/04 23:40:09 gad Exp $");
35#endif
36
37#ifndef lint
38static const char copyright[] =
39"@(#) Copyright (c) 1980, 1991, 1993, 1994\n\
40	The Regents of the University of California.  All rights reserved.\n";
41#endif
42
43#ifndef lint
44static const char sccsid[] = "@(#)w.c	8.4 (Berkeley) 4/16/94";
45#endif
46
47/*
48 * w - print system status (who and what)
49 *
50 * This program is similar to the systat command on Tenex/Tops 10/20
51 *
52 */
53#include <sys/param.h>
54#include <sys/time.h>
55#include <sys/stat.h>
56#include <sys/sysctl.h>
57#include <sys/proc.h>
58#include <sys/user.h>
59#include <sys/ioctl.h>
60#include <sys/socket.h>
61#include <sys/tty.h>
62
63#ifndef __APPLE__
64#include <machine/cpu.h>
65#endif
66#include <netinet/in.h>
67#include <arpa/inet.h>
68#include <arpa/nameser.h>
69
70#include <ctype.h>
71#include <err.h>
72#include <errno.h>
73#include <fcntl.h>
74#if HAVE_KVM
75#include <kvm.h>
76#endif
77#include <langinfo.h>
78#include <libutil.h>
79#include <limits.h>
80#include <locale.h>
81#include <netdb.h>
82#include <nlist.h>
83#include <paths.h>
84#include <resolv.h>
85#include <stdio.h>
86#include <stdlib.h>
87#include <string.h>
88#include <timeconv.h>
89#include <unistd.h>
90#if HAVE_UTMPX
91#include <utmpx.h>
92/* use utmp values so formatting is the same */
93#define UT_NAMESIZE	8
94#define UT_LINESIZE	8
95#else /* HAVE_UTMPX */
96#include <utmp.h>
97#endif /* HAVE_UTMPX */
98#include <vis.h>
99
100#include <TargetConditionals.h>
101
102#include "extern.h"
103
104struct timeval	boottime;
105#if !HAVE_UTMPX
106struct utmp	utmp;
107#endif
108struct winsize	ws;
109#if HAVE_KVM
110kvm_t	       *kd;
111#endif
112time_t		now;		/* the current time of day */
113int		ttywidth;	/* width of tty */
114int		argwidth;	/* width of tty */
115int		header = 1;	/* true if -h flag: don't print heading */
116#if !HAVE_UTMPX
117int		nflag;		/* true if -n flag: don't convert addrs */
118#endif
119#ifndef __APPLE__
120int		dflag;		/* true if -d flag: output debug info */
121#endif
122int		sortidle;	/* sort by idle time */
123int		use_ampm;	/* use AM/PM time */
124int             use_comma;      /* use comma as floats separator */
125char	      **sel_users;	/* login array of particular users selected */
126
127/*
128 * One of these per active utmp entry.
129 */
130struct	entry {
131	struct	entry *next;
132#if HAVE_UTMPX
133	struct	utmpx utmp;
134#else
135	struct	utmp utmp;
136#endif
137	dev_t	tdev;			/* dev_t of terminal */
138	time_t	idle;			/* idle time of terminal in seconds */
139	struct	kinfo_proc *kp;		/* `most interesting' proc */
140	char	*args;			/* arg list of interesting process */
141	struct	kinfo_proc *dkp;	/* debug option proc list */
142} *ep, *ehead = NULL, **nextp = &ehead;
143
144#ifndef __APPLE__
145#define	debugproc(p) *((struct kinfo_proc **)&(p)->ki_udata)
146#else
147#define debugproc(p) *((struct kinfo_proc **)&(p)->ki_spare[0])
148#endif
149
150/* W_DISPHOSTSIZE should not be greater than UT_HOSTSIZE */
151#define	W_DISPHOSTSIZE	16
152
153static void		 pr_header(time_t *, int);
154static struct stat	*ttystat(char *, int);
155static void		 usage(int);
156static int		 this_is_uptime(const char *s);
157#if !HAVE_KVM
158static void		 w_getargv(void);
159#endif
160
161char *fmt_argv(char **, char *, int);	/* ../../bin/ps/fmt.c */
162
163int
164main(int argc, char *argv[])
165{
166	struct kinfo_proc *kp;
167	struct kinfo_proc *kprocbuf;
168	struct kinfo_proc *dkp;
169	struct stat *stp;
170#if HAVE_UTMPX
171	struct utmpx *ux;
172#else
173	FILE *ut;
174#endif
175	time_t touched;
176#if HAVE_KVM
177	int ch, i, nentries, nusers, wcmd, longidle, dropgid;
178	const char *memf, *nlistf, *p;
179#else
180	int ch, i, nentries, nusers, wcmd, longidle;
181	const char *p;
182#endif /* HAVE_KVM */
183	char *x_suffix;
184#ifdef __APPLE__
185	char buf[MAXHOSTNAMELEN];
186#else
187	char buf[MAXHOSTNAMELEN], errbuf[_POSIX2_LINE_MAX];
188	char fn[MAXHOSTNAMELEN];
189#endif /* __APPLE__ */
190	char *dot;
191#if !HAVE_KVM
192	int local_error = 0, retry_count = 0;
193	size_t bufSize = 0;
194	size_t orig_bufSize = 0;
195	int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_ALL, 0 };
196#endif
197
198	(void)setlocale(LC_ALL, "");
199#ifndef __APPLE__
200	use_ampm = (*nl_langinfo(T_FMT_AMPM) != '\0');
201	use_comma = (*nl_langinfo(RADIXCHAR) != ',');
202#endif
203
204	/* Are we w(1) or uptime(1)? */
205	if (this_is_uptime(argv[0]) == 0) {
206		wcmd = 0;
207		p = "";
208	} else {
209		wcmd = 1;
210		p = "dhiflM:N:nsuw";
211	}
212
213#if HAVE_KVM
214	dropgid = 0;
215	memf = nlistf = _PATH_DEVNULL;
216#endif
217	while ((ch = getopt(argc, argv, p)) != -1)
218		switch (ch) {
219#ifndef __APPLE__
220		case 'd':
221			dflag = 1;
222			break;
223#endif
224		case 'h':
225			header = 0;
226			break;
227		case 'i':
228			sortidle = 1;
229			break;
230#if HAVE_KVM
231		case 'M':
232			header = 0;
233			memf = optarg;
234			dropgid = 1;
235			break;
236		case 'N':
237			nlistf = optarg;
238			dropgid = 1;
239			break;
240#endif /* HAVE_KVM */
241#if !HAVE_UTMPX
242		case 'n':
243			nflag = 1;
244			break;
245#else /* !HAVE_UTMPX */
246		case 'n':
247#endif /* !HAVE_UTMPX */
248		case 'f': case 'l': case 's': case 'u': case 'w':
249#if !HAVE_KVM
250		case 'M': case 'N':
251#endif
252#ifdef __APPLE__
253		case 'd':
254			warnx("[-MNdflnsuw] no longer supported");
255#else
256			warnx("[-flsuw] no longer supported");
257#endif
258			/* FALLTHROUGH */
259		case '?':
260		default:
261			usage(wcmd);
262		}
263	argc -= optind;
264	argv += optind;
265
266#if !TARGET_OS_EMBEDDED
267	if (!(_res.options & RES_INIT))
268		res_init();
269	_res.retrans = 2;	/* resolver timeout to 2 seconds per try */
270	_res.retry = 1;		/* only try once.. */
271#endif
272
273#if HAVE_KVM
274	/*
275	 * Discard setgid privileges if not the running kernel so that bad
276	 * guys can't print interesting stuff from kernel memory.
277	 */
278	if (dropgid)
279		setgid(getgid());
280
281	if ((kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf)) == NULL)
282		errx(1, "%s", errbuf);
283#endif
284
285	(void)time(&now);
286#if HAVE_UTMPX
287	setutxent();
288#else
289	if ((ut = fopen(_PATH_UTMP, "r")) == NULL)
290		err(1, "%s", _PATH_UTMP);
291#endif
292
293	if (*argv)
294		sel_users = argv;
295
296#if HAVE_UTMPX
297	for (nusers = 0; (ux = getutxent());) {
298		if (ux->ut_user[0] == '\0' || ux->ut_type != USER_PROCESS)
299			continue;
300		if (!(stp = ttystat(ux->ut_line, sizeof(ux->ut_line))))
301			continue;	/* corrupted record */
302#else
303	for (nusers = 0; fread(&utmp, sizeof(utmp), 1, ut);) {
304		if (utmp.ut_name[0] == '\0')
305			continue;
306		if (!(stp = ttystat(utmp.ut_line, UT_LINESIZE)))
307			continue;	/* corrupted record */
308#endif
309		++nusers;
310		if (wcmd == 0)
311			continue;
312		if (sel_users) {
313			int usermatch;
314			char **user;
315
316			usermatch = 0;
317			for (user = sel_users; !usermatch && *user; user++)
318#if HAVE_UTMPX
319				if (!strncmp(ux->ut_user, *user, sizeof(ux->ut_user)))
320#else
321				if (!strncmp(utmp.ut_name, *user, UT_NAMESIZE))
322#endif
323					usermatch = 1;
324			if (!usermatch)
325				continue;
326		}
327		if ((ep = calloc(1, sizeof(struct entry))) == NULL)
328			errx(1, "calloc");
329		*nextp = ep;
330		nextp = &ep->next;
331#if HAVE_UTMPX
332		memmove(&ep->utmp, ux, sizeof(*ux));
333#else
334		memmove(&ep->utmp, &utmp, sizeof(struct utmp));
335#endif
336		ep->tdev = stp->st_rdev;
337#ifdef CPU_CONSDEV
338		/*
339		 * If this is the console device, attempt to ascertain
340		 * the true console device dev_t.
341		 */
342		if (ep->tdev == 0) {
343			int mib[2];
344			size_t size;
345
346			mib[0] = CTL_MACHDEP;
347			mib[1] = CPU_CONSDEV;
348			size = sizeof(dev_t);
349			(void)sysctl(mib, 2, &ep->tdev, &size, NULL, 0);
350		}
351#endif
352		touched = stp->st_atime;
353#ifdef __APPLE__
354		if (touched < ep->utmp.ut_tv.tv_sec) {
355			/* tty untouched since before login */
356			touched = ep->utmp.ut_tv.tv_sec;
357		}
358#else
359		if (touched < ep->utmp.ut_time) {
360			/* tty untouched since before login */
361			touched = ep->utmp.ut_time;
362		}
363#endif
364		if ((ep->idle = now - touched) < 0)
365			ep->idle = 0;
366	}
367#if HAVE_UTMPX
368	endutxent();
369#else
370	(void)fclose(ut);
371#endif
372
373	if (header || wcmd == 0) {
374		pr_header(&now, nusers);
375		if (wcmd == 0) {
376#if HAVE_KVM
377			(void)kvm_close(kd);
378#endif
379			exit(0);
380		}
381
382#define HEADER_USER		"USER"
383#define HEADER_TTY		"TTY"
384#define HEADER_FROM		"FROM"
385#define HEADER_LOGIN_IDLE	"LOGIN@  IDLE "
386#define HEADER_WHAT		"WHAT\n"
387#define WUSED  (UT_NAMESIZE + UT_LINESIZE + W_DISPHOSTSIZE + \
388		sizeof(HEADER_LOGIN_IDLE) + 3)	/* header width incl. spaces */
389		(void)printf("%-*.*s %-*.*s %-*.*s  %s",
390				UT_NAMESIZE, UT_NAMESIZE, HEADER_USER,
391				UT_LINESIZE, UT_LINESIZE, HEADER_TTY,
392				W_DISPHOSTSIZE, W_DISPHOSTSIZE, HEADER_FROM,
393				HEADER_LOGIN_IDLE HEADER_WHAT);
394	}
395
396#if HAVE_KVM
397	if ((kp = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nentries)) == NULL)
398		err(1, "%s", kvm_geterr(kd));
399#else
400	mib[0] = CTL_KERN;
401	mib[1] = KERN_PROC;
402	mib[2] = KERN_PROC_ALL;
403	mib[3] = 0;
404
405	if (sysctl(mib, 4, NULL, &bufSize, NULL, 0) < 0) {
406		perror("Failure calling sysctl");
407		exit(1);
408	}
409
410	kprocbuf = kp = (struct kinfo_proc *)malloc(bufSize);
411
412	retry_count = 0;
413	orig_bufSize = bufSize;
414	for (retry_count = 0; ; retry_count++) {
415		local_error = 0;
416		bufSize = orig_bufSize;
417		if ((local_error = sysctl(mib, 4, kp, &bufSize, NULL, 0)) < 0) {
418			if (retry_count < 1000) {
419				sleep(1);
420				continue;
421			}
422			perror("Failure calling sysctl");
423			exit(1);
424		} else if (local_error == 0) {
425			break;
426		}
427		sleep(1);
428	}
429	nentries = bufSize / sizeof(struct kinfo_proc);
430#endif /* !HAVE_KVM */
431
432#if !HAVE_KVM
433#define ki_stat		kp_proc.p_stat
434#define ki_pgid		kp_eproc.e_pgid
435#define ki_tpgid	kp_eproc.e_tpgid
436#define ki_tdev		kp_eproc.e_tdev
437#endif /* !HAVE_KVM */
438	for (i = 0; i < nentries; i++, kp++) {
439		if (kp->ki_stat == SIDL || kp->ki_stat == SZOMB)
440			continue;
441		for (ep = ehead; ep != NULL; ep = ep->next) {
442			if (ep->tdev == kp->ki_tdev) {
443				/*
444				 * proc is associated with this terminal
445				 */
446				if (ep->kp == NULL && kp->ki_pgid == kp->ki_tpgid) {
447					/*
448					 * Proc is 'most interesting'
449					 */
450					if (proc_compare(ep->kp, kp))
451						ep->kp = kp;
452				}
453				/*
454				 * Proc debug option info; add to debug
455				 * list using kinfo_proc ki_spare[0]
456				 * as next pointer; ptr to ptr avoids the
457				 * ptr = long assumption.
458				 */
459				dkp = ep->dkp;
460				ep->dkp = kp;
461#ifndef __APPLE__
462				debugproc(kp) = dkp;
463#endif
464			}
465		}
466	}
467	if ((ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 &&
468	     ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) == -1 &&
469	     ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == -1) || ws.ws_col == 0)
470	       ttywidth = 79;
471        else
472	       ttywidth = ws.ws_col - 1;
473	argwidth = ttywidth - WUSED;
474	if (argwidth < 4)
475		argwidth = 8;
476	for (ep = ehead; ep != NULL; ep = ep->next) {
477		if (ep->kp == NULL) {
478			ep->args = strdup("-");
479			continue;
480		}
481#if HAVE_KVM
482		ep->args = fmt_argv(kvm_getargv(kd, ep->kp, argwidth),
483		    ep->kp->ki_comm, MAXCOMLEN);
484#else
485		w_getargv();
486#endif /* HAVE_KVM */
487		if (ep->args == NULL)
488			err(1, NULL);
489	}
490	/* sort by idle time */
491	if (sortidle && ehead != NULL) {
492		struct entry *from, *save;
493
494		from = ehead;
495		ehead = NULL;
496		while (from != NULL) {
497			for (nextp = &ehead;
498			    (*nextp) && from->idle >= (*nextp)->idle;
499			    nextp = &(*nextp)->next)
500				continue;
501			save = from;
502			from = from->next;
503			save->next = *nextp;
504			*nextp = save;
505		}
506	}
507
508	for (ep = ehead; ep != NULL; ep = ep->next) {
509#if HAVE_UTMPX
510		char host_buf[sizeof(ep->utmp.ut_host) + 1];
511		strlcpy(host_buf, ep->utmp.ut_host, sizeof(host_buf));
512#else
513		char host_buf[UT_HOSTSIZE + 1];
514		struct sockaddr_storage ss;
515		struct sockaddr *sa = (struct sockaddr *)&ss;
516		struct sockaddr_in *lsin = (struct sockaddr_in *)&ss;
517		struct sockaddr_in6 *lsin6 = (struct sockaddr_in6 *)&ss;
518		time_t t;
519		int isaddr;
520
521		host_buf[UT_HOSTSIZE] = '\0';
522		strncpy(host_buf, ep->utmp.ut_host, UT_HOSTSIZE);
523#endif /* HAVE_UTMPX */
524		p = *host_buf ? host_buf : "-";
525		if ((x_suffix = strrchr(p, ':')) != NULL) {
526			if ((dot = strchr(x_suffix, '.')) != NULL &&
527			    strchr(dot+1, '.') == NULL)
528				*x_suffix++ = '\0';
529			else
530				x_suffix = NULL;
531		}
532#if !HAVE_UTMPX
533		if (!nflag) {
534			/* Attempt to change an IP address into a name */
535			isaddr = 0;
536			memset(&ss, '\0', sizeof(ss));
537			if (inet_pton(AF_INET6, p, &lsin6->sin6_addr) == 1) {
538				lsin6->sin6_len = sizeof(*lsin6);
539				lsin6->sin6_family = AF_INET6;
540				isaddr = 1;
541			} else if (inet_pton(AF_INET, p, &lsin->sin_addr) == 1) {
542				lsin->sin_len = sizeof(*lsin);
543				lsin->sin_family = AF_INET;
544				isaddr = 1;
545			}
546			if (isaddr && realhostname_sa(fn, sizeof(fn), sa,
547			    sa->sa_len) == HOSTNAME_FOUND)
548				p = fn;
549		}
550#endif /* !HAVE_UTMPX */
551		if (x_suffix) {
552			(void)snprintf(buf, sizeof(buf), "%s:%s", p, x_suffix);
553			p = buf;
554		}
555#ifndef __APPLE__
556		if (dflag) {
557			for (dkp = ep->dkp; dkp != NULL; dkp = debugproc(dkp)) {
558				const char *ptr;
559
560				ptr = fmt_argv(kvm_getargv(kd, dkp, argwidth),
561				    dkp->ki_comm, MAXCOMLEN);
562				if (ptr == NULL)
563					ptr = "-";
564				(void)printf("\t\t%-9d %s\n",
565				    dkp->ki_pid, ptr);
566			}
567		}
568#endif /* !__APPLE__ */
569		(void)printf("%-*.*s %-*.*s %-*.*s ",
570#if HAVE_UTMPX
571		    UT_NAMESIZE, (int)sizeof(ep->utmp.ut_user), ep->utmp.ut_user,
572		    UT_LINESIZE, (int)sizeof(ep->utmp.ut_line),
573#else
574		    UT_NAMESIZE, UT_NAMESIZE, ep->utmp.ut_name,
575		    UT_LINESIZE, UT_LINESIZE,
576#endif
577		    strncmp(ep->utmp.ut_line, "tty", 3) &&
578		    strncmp(ep->utmp.ut_line, "cua", 3) ?
579		    ep->utmp.ut_line : ep->utmp.ut_line + 3,
580		    W_DISPHOSTSIZE, W_DISPHOSTSIZE, *p ? p : "-");
581#ifdef __APPLE__
582		pr_attime(&ep->utmp.ut_tv.tv_sec, &now);
583#else
584		t = _time_to_time32(ep->utmp.ut_time);
585		pr_attime(&t, &now);
586#endif
587		longidle = pr_idle(ep->idle);
588		(void)printf("%.*s\n", argwidth - longidle, ep->args);
589#ifdef __APPLE__
590		free(ep->args);
591#endif
592	}
593#if HAVE_KVM
594	(void)kvm_close(kd);
595#else
596	free(kprocbuf);
597#endif /* HAVE_KVM */
598	exit(0);
599}
600
601static void
602pr_header(time_t *nowp, int nusers)
603{
604	double avenrun[3];
605	time_t uptime;
606	int days, hrs, i, mins, secs;
607	int mib[2];
608	size_t size;
609	char buf[256];
610
611	/*
612	 * Print time of day.
613	 */
614	if (strftime(buf, sizeof(buf),
615	    use_ampm ? "%l:%M%p" : "%k:%M", localtime(nowp)) != 0)
616		(void)printf("%s ", buf);
617	/*
618	 * Print how long system has been up.
619	 * (Found by looking getting "boottime" from the kernel)
620	 */
621	mib[0] = CTL_KERN;
622	mib[1] = KERN_BOOTTIME;
623	size = sizeof(boottime);
624	if (sysctl(mib, 2, &boottime, &size, NULL, 0) != -1 &&
625	    boottime.tv_sec != 0) {
626		uptime = now - boottime.tv_sec;
627		if (uptime > 60)
628			uptime += 30;
629		days = uptime / 86400;
630		uptime %= 86400;
631		hrs = uptime / 3600;
632		uptime %= 3600;
633		mins = uptime / 60;
634		secs = uptime % 60;
635		(void)printf(" up");
636		if (days > 0)
637			(void)printf(" %d day%s,", days, days > 1 ? "s" : "");
638		if (hrs > 0 && mins > 0)
639			(void)printf(" %2d:%02d,", hrs, mins);
640		else if (hrs > 0)
641			(void)printf(" %d hr%s,", hrs, hrs > 1 ? "s" : "");
642		else if (mins > 0)
643			(void)printf(" %d min%s,", mins, mins > 1 ? "s" : "");
644		else
645			(void)printf(" %d sec%s,", secs, secs > 1 ? "s" : "");
646	}
647
648	/* Print number of users logged in to system */
649	(void)printf(" %d user%s", nusers, nusers == 1 ? "" : "s");
650
651	/*
652	 * Print 1, 5, and 15 minute load averages.
653	 */
654	if (getloadavg(avenrun, sizeof(avenrun) / sizeof(avenrun[0])) == -1)
655		(void)printf(", no load average information available\n");
656	else {
657		(void)printf(", load averages:");
658		for (i = 0; i < (int)(sizeof(avenrun) / sizeof(avenrun[0])); i++) {
659			if (use_comma && i > 0)
660				(void)printf(",");
661			(void)printf(" %.2f", avenrun[i]);
662		}
663		(void)printf("\n");
664	}
665}
666
667static struct stat *
668ttystat(char *line, int sz)
669{
670	static struct stat sb;
671	char ttybuf[MAXPATHLEN];
672
673	(void)snprintf(ttybuf, sizeof(ttybuf), "%s%.*s", _PATH_DEV, sz, line);
674	if (stat(ttybuf, &sb) == 0) {
675		return (&sb);
676	} else {
677		warn("%s", ttybuf);
678		return (NULL);
679	}
680}
681
682static void
683usage(int wcmd)
684{
685	if (wcmd)
686		(void)fprintf(stderr,
687		    "usage: w [hi] [user ...]\n");
688	else
689		(void)fprintf(stderr, "usage: uptime\n");
690	exit(1);
691}
692
693static int
694this_is_uptime(const char *s)
695{
696	const char *u;
697
698	if ((u = strrchr(s, '/')) != NULL)
699		++u;
700	else
701		u = s;
702	if (strcmp(u, "uptime") == 0)
703		return (0);
704	return (-1);
705}
706
707#if !HAVE_KVM
708static void
709w_getargv(void)
710{
711	int mib[3], argmax;
712	size_t size;
713	char *procargs, *sp, *np, *cp;
714
715	mib[0] = CTL_KERN;
716	mib[1] = KERN_ARGMAX;
717
718	size = sizeof(argmax);
719	if (sysctl(mib, 2, &argmax, &size, NULL, 0) == -1) {
720		goto ERROR;
721	}
722
723	procargs = malloc(argmax);
724	if (procargs == NULL) {
725		goto ERROR;
726	}
727
728	mib[0] = CTL_KERN;
729	mib[1] = KERN_PROCARGS;
730	mib[2] = KI_PROC(ep)->p_pid;
731
732	size = (size_t)argmax;
733	if (sysctl(mib, 3, procargs, &size, NULL, 0) == -1) {
734		goto ERROR_FREE;
735	}
736
737	for (cp = procargs; cp < &procargs[size]; cp++) {
738		if (*cp == '\0') {
739			break;
740		}
741	}
742	if (cp == &procargs[size]) {
743		goto ERROR_FREE;
744	}
745
746	sp = cp;
747
748	for (np = NULL; cp < &procargs[size]; cp++) {
749		if (*cp == '\0') {
750			if (np != NULL) {
751				*np = ' ';
752			}
753			np = cp;
754		} else if (*cp == '=') {
755			break;
756		}
757	}
758
759	for (np = sp; (np < &procargs[size]) && (*np == ' '); np++);
760
761	ep->args = strdup(np);
762	free(procargs);
763	return;
764
765ERROR_FREE:
766	free(procargs);
767ERROR:
768/*
769	ep->args = malloc(2);
770	ep->args[0] = '-';
771	ep->args[1] = '\0';
772*/
773	asprintf(&ep->args, "%s", KI_PROC(ep)->p_comm);
774	return;
775}
776#endif /* HAVE_KVM */
777