/usr/src/usr.bin/w/w.c

Bug Summary

File:	src/usr.bin/w/w.c
Warning:	line 367, column 9 Null pointer passed as 1st argument to string length function

Annotated Source Code

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Show analyzer invocation

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name w.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.bin/w/obj -resource-dir /usr/local/llvm16/lib/clang/16 -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/w/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/scan/2024-01-11-140451-98009-1 -x c /usr/src/usr.bin/w/w.c

1/*	$OpenBSD: w.c,v 1.68 2022/12/04 23:50:50 cheloha Exp $	*/
2 
3/*-
4 * Copyright (c) 1980, 1991, 1993, 1994
5 *	The Regents of the University of California.  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 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31 
32/*
33 * w - print system status (who and what)
34 *
35 * This program is similar to the systat command on Tenex/Tops 10/20
36 *
37 */
38#include <sys/time.h>
39#include <sys/stat.h>
40#include <sys/sysctl.h>
41#include <sys/signal.h>
42#include <sys/proc.h>
43#include <sys/ioctl.h>
44#include <sys/socket.h>
45#include <sys/tty.h>
46 
47#include <netinet/in.h>
48#include <arpa/inet.h>
49 
50#include <ctype.h>
51#include <err.h>
52#include <errno(*__errno()).h>
53#include <fcntl.h>
54#include <kvm.h>
55#include <netdb.h>
56#include <nlist.h>
57#include <paths.h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <string.h>
61#include <unistd.h>
62#include <limits.h>
63#include <utmp.h>
64#include <vis.h>
65 
66#include "extern.h"
67 
68struct utmp	utmp;
69struct winsize	ws;
70kvm_t	       *kd;
71time_t		now;		/* the current time of day */
72int		ttywidth;	/* width of tty */
73int		argwidth;	/* width of tty */
74int		header = 1;	/* true if -h flag: don't print heading */
75int		nflag = 1;	/* true if -n flag: don't convert addrs */
76int		sortidle;	/* sort by idle time */
77char	       *sel_user;	/* login of particular user selected */
78char		domain[HOST_NAME_MAX255+1];
79 
80#define	NAME_WIDTH8	8
81#define HOST_WIDTH16	16
82 
83/*
84 * One of these per active utmp entry.
85 */
86struct	entry {
87	struct	entry *next;
88	struct	utmp utmp;
89	dev_t	tdev;			/* dev_t of terminal */
90	time_t	idle;			/* idle time of terminal in seconds */
91	struct	kinfo_proc *kp;		/* `most interesting' proc */
92} *ep, *ehead = NULL((void *)0), **nextp = &ehead;
93 
94static void	 fmt_putc(int, int *);
95static void	 fmt_puts(const char *, int *);
96static void	 pr_args(struct kinfo_proc *);
97static void	 pr_header(time_t *, int);
98static struct stat
99		*ttystat(char *);
100static void	 usage(int);
101 
102int
103main(int argc, char *argv[])
104{
105	extern char *__progname;
106	struct kinfo_proc *kp;
107	struct hostent *hp;
108	struct stat *stp;
109	FILE *ut;
110	struct in_addr addr;
111	int ch, i, nentries, nusers, wcmd;
112	char *memf, *nlistf, *p, *x;
113	char buf[HOST_NAME_MAX255+1], errbuf[_POSIX2_LINE_MAX2048];
114 
115	/* Are we w(1) or uptime(1)? */
116	p = __progname;
117	if (*p == '-')
1
Assuming the condition is false→
118		p++;
119	if (p[0] == 'w' && p[1] == '\0') {
2
←
Assuming the condition is true→
3
←
Assuming the condition is true→
4
←
Taking true branch→
120		wcmd = 1;
121		p = "hiflM:N:asuw";
122	} else if (!strcmp(p, "uptime")) {
123		wcmd = 0;
124		p = "";
125	} else
126		errx(1,
127		 "this program should be invoked only as \"w\" or \"uptime\"");
128 
129	memf = nlistf = NULL((void *)0);
130	while ((ch = getopt(argc, argv, p)) != -1)
5
←
Assuming the condition is false→
6
←
Loop condition is false. Execution continues on line 154→
131		switch (ch) {
132		case 'h':
133			header = 0;
134			break;
135		case 'i':
136			sortidle = 1;
137			break;
138		case 'M':
139			header = 0;
140			memf = optarg;
141			break;
142		case 'N':
143			nlistf = optarg;
144			break;
145		case 'a':
146			nflag = 0;
147			break;
148		case 'f': case 'l': case 's': case 'u': case 'w':
149			warnx("[-flsuw] no longer supported");
150			/* FALLTHROUGH */
151		default:
152			usage(wcmd);
153		}
154	argc -= optind;
155	argv += optind;
156 
157	if (nflag6.1
'nflag' is not equal to 0
 == 0) {
7
←
Taking false branch→
158		if (pledge("stdio tty rpath dns ps vminfo", NULL((void *)0)) == -1)
159			err(1, "pledge");
160	} else {
161		if (pledge("stdio tty rpath ps vminfo", NULL((void *)0)) == -1)
8
←
Assuming the condition is false→
162			err(1, "pledge");
163	}
164 
165	if (nlistf8.1
'nlistf' is equal to NULL
 == NULL((void *)0) && memf8.2
'memf' is equal to NULL
 == NULL((void *)0)) {
9
←
Taking true branch→
166		if ((kd = kvm_openfiles(nlistf, memf, NULL((void *)0), KVM_NO_FILES0x80000000,
10
←
Assuming the condition is false→
11
←
Taking false branch→
167		    errbuf)) == NULL((void *)0))
168			errx(1, "%s", errbuf);
169	} else {
170		if ((kd = kvm_openfiles(nlistf, memf, NULL((void *)0), O_RDONLY0x0000, errbuf)) == NULL((void *)0))
171			errx(1, "%s", errbuf);
172	}
173 
174	(void)time(&now);
175	if ((ut = fopen(_PATH_UTMP"/var/run/utmp", "r")) == NULL((void *)0))
12
←
Assuming the condition is false→
13
←
Taking false branch→
176		err(1, "%s", _PATH_UTMP"/var/run/utmp");
177 
178	if (*argv)
14
←
Assuming the condition is false→
15
←
Taking false branch→
179		sel_user = *argv;
180 
181	for (nusers = 0; fread(&utmp, sizeof(utmp), 1, ut);) {
16
←
Loop condition is true.  Entering loop body→
28
←
Loop condition is false. Execution continues on line 214→
182		if (utmp.ut_name[0] == '\0')
17
←
Assuming the condition is false→
18
←
Taking false branch→
183			continue;
184		++nusers;
185		if (wcmd18.1
'wcmd' is not equal to 0
 == 0 || (sel_user &&
19
←
Assuming 'sel_user' is null→
186		    strncmp(utmp.ut_name, sel_user, UT_NAMESIZE32) != 0))
187			continue;
188		if ((ep = calloc(1, sizeof(*ep))) == NULL((void *)0))
20
←
Assuming the condition is false→
21
←
Taking false branch→
189			err(1, NULL((void *)0));
190		*nextp = ep;
191		nextp = &(ep->next);
192		memcpy(&(ep->utmp), &utmp, sizeof(utmp));
193		if (!(stp = ttystat(ep->utmp.ut_line)))
22
←
Assuming 'stp' is non-null→
23
←
Taking false branch→
194			continue;
195		ep->tdev = stp->st_rdev;
196 
197		/*
198		 * If this is the console device, attempt to ascertain
199		 * the true console device dev_t.
200		 */
201		if (ep->tdev == 0) {
24
←
Assuming field 'tdev' is not equal to 0→
25
←
Taking false branch→
202			int mib[2];
203			size_t size;
204 
205			mib[0] = CTL_KERN1;
206			mib[1] = KERN_CONSDEV75;
207			size = sizeof(dev_t);
208			(void) sysctl(mib, 2, &ep->tdev, &size, NULL((void *)0), 0);
209		}
210 
211		if ((ep->idle = now - stp->st_atimest_atim.tv_sec) < 0)
26
←
Assuming the condition is false→
27
←
Taking false branch→
212			ep->idle = 0;
213	}
214	(void)fclose(ut);
215 
216	if (header || wcmd29.1
'wcmd' is not equal to 0
 == 0) {
29
←
Assuming 'header' is 0→
30
←
Taking false branch→
217		pr_header(&now, nusers);
218		if (wcmd == 0)
219			exit (0);
220	}
221 
222#define HEADER"USER    TTY FROM              LOGIN@  IDLE WHAT"	"USER    TTY FROM              LOGIN@  IDLE WHAT"
223#define WUSED(sizeof("USER    TTY FROM              LOGIN@  IDLE WHAT") - sizeof
("WHAT"))	(sizeof(HEADER"USER    TTY FROM              LOGIN@  IDLE WHAT") - sizeof("WHAT"))
224	if (header30.1
'header' is 0
)
31
←
Taking false branch→
225		(void)puts(HEADER"USER    TTY FROM              LOGIN@  IDLE WHAT");
226 
227	kp = kvm_getprocs(kd, KERN_PROC_ALL0, 0, sizeof(*kp), &nentries);
228	if (kp == NULL((void *)0))
32
←
Assuming 'kp' is not equal to NULL→
229		errx(1, "%s", kvm_geterr(kd));
230 
231	if ((ioctl(STDOUT_FILENO1, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) == -1 &&
33
←
Assuming the condition is false→
35
←
Taking false branch→
232	    ioctl(STDERR_FILENO2, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) == -1 &&
233	    ioctl(STDIN_FILENO0, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) == -1) || ws.ws_col == 0)
34
←
Assuming field 'ws_col' is not equal to 0→
234		ttywidth = 79;
235	else
236		ttywidth = ws.ws_col - 1;
237	argwidth = ttywidth - WUSED(sizeof("USER    TTY FROM              LOGIN@  IDLE WHAT") - sizeof
("WHAT"));
238	if (argwidth < 4)
36
←
Assuming 'argwidth' is >= 4→
37
←
Taking false branch→
239		argwidth = 8;
240 
241	for (i = 0; i < nentries; i++, kp++) {
38
←
Assuming 'i' is >= 'nentries'→
242		if (kp->p_psflags & (PS_EMBRYO0x00020000 | PS_ZOMBIE0x00040000))
243			continue;
244		for (ep = ehead; ep != NULL((void *)0); ep = ep->next) {
245			/* ftp is a special case. */
246			if (strncmp(ep->utmp.ut_line, "ftp", 3) == 0) {
247				char pidstr[UT_LINESIZE8-2];
248				pid_t fp;
249 
250				(void)strncpy(pidstr, &ep->utmp.ut_line[3],
251				    sizeof(pidstr) - 1);
252				pidstr[sizeof(pidstr) - 1] = '\0';
253				fp = (pid_t)strtol(pidstr, NULL((void *)0), 10);
254				if (kp->p_pid == fp) {
255					ep->kp = kp;
256					break;
257				}
258			} else if (ep->tdev == kp->p_tdev &&
259			    kp->p__pgid == kp->p_tpgid) {
260				/*
261				 * Proc is in foreground of this terminal
262				 */
263				if (proc_compare(ep->kp, kp))
264					ep->kp = kp;
265				break;
266			}
267		}
268	}
269	/* sort by idle time */
270	if (sortidle && ehead != NULL((void *)0)) {
39
←
Assuming 'sortidle' is 0→
271		struct entry *from = ehead, *save;
272 
273		ehead = NULL((void *)0);
274		while (from != NULL((void *)0)) {
275			for (nextp = &ehead;
276			    (*nextp) && from->idle >= (*nextp)->idle;
277			    nextp = &(*nextp)->next)
278				continue;
279			save = from;
280			from = from->next;
281			save->next = *nextp;
282			*nextp = save;
283		}
284	}
285 
286	if (!nflag) {
40
←
Assuming 'nflag' is not equal to 0→
41
←
Taking false branch→
287		if (gethostname(domain, sizeof(domain)) == -1 ||
288		    (p = strchr(domain, '.')) == 0)
289			domain[0] = '\0';
290		else {
291			domain[sizeof(domain) - 1] = '\0';
292			memmove(domain, p, strlen(p) + 1);
293		}
294	}
295 
296	for (ep = ehead; ep != NULL((void *)0); ep = ep->next) {
42
←
Assuming 'ep' is not equal to NULL→
297		p = *ep->utmp.ut_host ? ep->utmp.ut_host : "-";
43
←
Loop condition is true.  Entering loop body→
44
←
Assuming the condition is false→
45
←
'?' condition is false→
298		for (x = NULL((void *)0), i = 0; p[i] != '\0' && i < UT_HOSTSIZE256; i++)
46
←
Loop condition is true.  Entering loop body→
299			if (p[i] == ':') {
47
←
Taking false branch→
300				x = &p[i];
301				*x++ = '\0';
302				break;
303			}
304		if (!nflag47.1
'nflag' is not equal to 0
 && inet_aton(p, &addr) &&
305		    (hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET2))) {
306			if (domain[0] != '\0') {
307				p = hp->h_name;
308				p += strlen(hp->h_name);
309				p -= strlen(domain);
310				if (p > hp->h_name &&
311				    strcasecmp(p, domain) == 0)
312					*p = '\0';
313			}
314			p = hp->h_name;
315		}
316		if (x47.2
'x' is null
) {
48
←
Taking false branch→
317			(void)snprintf(buf, sizeof(buf), "%s:%.*s", p,
318			    (int)(ep->utmp.ut_host + UT_HOSTSIZE256 - x), x);
319			p = buf;
320		}
321		(void)printf("%-*.*s %-2.2s %-*.*s ",
322		    NAME_WIDTH8, UT_NAMESIZE32, ep->utmp.ut_name,
323		    strncmp(ep->utmp.ut_line, "tty", 3) ?
49
←
Assuming the condition is false→
50
←
'?' condition is false→
324		    ep->utmp.ut_line : ep->utmp.ut_line + 3,
325		    HOST_WIDTH16, HOST_WIDTH16, *p ? p : "-");
51
←
'?' condition is true→
326		pr_attime(&ep->utmp.ut_time, &now);
327		pr_idle(ep->idle);
328		pr_args(ep->kp);
52
←
Calling 'pr_args'→
329		printf("\n");
330	}
331	exit(0);
332}
333 
334static void
335fmt_putc(int c, int *leftp)
336{
337 
338	if (*leftp == 0)
339		return;
340	if (*leftp != -1)
341		*leftp -= 1;
342	putchar(c)(!__isthreaded ? __sputc(c, (&__sF[1])) : (putc)(c, (&
__sF[1])));
343}
344 
345static void
346fmt_puts(const char *s, int *leftp)
347{
348	static char *v = NULL((void *)0);
63
←
'v' initialized to a null pointer value→
349	static size_t maxlen = 0;
350	size_t len;
351 
352	if (*leftp == 0)
64
←
Assuming the condition is false→
65
←
Taking false branch→
353		return;
354	len = strlen(s) * 4 + 1;
355	if (len > maxlen) {
66
←
Assuming 'len' is <= 'maxlen'→
67
←
Taking false branch→
356		free(v);
357		maxlen = 0;
358		if (len < getpagesize())
359			len = getpagesize();
360		v = malloc(len);
361		if (v == NULL((void *)0))
362			return;
363		maxlen = len;
364	}
365	strvis(v, s, VIS_TAB0x08 | VIS_NL0x10 | VIS_CSTYLE0x02);
366	if (*leftp != -1) {
68
←
Assuming the condition is true→
69
←
Taking true branch→
367		len = strlen(v);
70
←
Null pointer passed as 1st argument to string length function
368		if (len > *leftp) {
369			v[*leftp] = '\0';
370			*leftp = 0;
371		} else
372			*leftp -= len;
373	}
374	printf("%s", v);
375}
376 
377 
378static void
379pr_args(struct kinfo_proc *kp)
380{
381	char **argv, *str;
382	int left;
383 
384	if (kp == NULL((void *)0))
53
←
Assuming 'kp' is not equal to NULL→
54
←
Taking false branch→
385		goto nothing;		/* no matching process found */
386	left = argwidth;
387	argv = kvm_getargv(kd, kp, argwidth+60);  /* +60 for ftpd snip */
388	if (argv == NULL((void *)0))
55
←
Assuming 'argv' is not equal to NULL→
389		goto nothing;
390 
391	if (*argv == NULL((void *)0) || **argv == '\0') {
56
←
Assuming the condition is false→
57
←
Assuming the condition is false→
58
←
Taking false branch→
392		/* Process has zeroed argv[0], display executable name. */
393		fmt_putc('(', &left);
394		fmt_puts(kp->p_comm, &left);
395		fmt_putc(')', &left);
396	}
397	while (*argv) {
59
←
Loop condition is true.  Entering loop body→
398		/*
399		 * ftp argv[0] is in the following format:
400		 * ftpd: HOSTNAME: [USER/PASS: ]CMD args (ftpd)
401		 */
402		if (strncmp(*argv, "ftpd:", 5) == 0) {
60
←
Assuming the condition is false→
61
←
Taking false branch→
403			if ((str = strchr(*argv + 5, ':')) != NULL((void *)0))
404				str = strchr(str + 1, ':');
405			if (str != NULL((void *)0)) {
406				if ((str[0] == ':') &&
407				    isspace((unsigned char)str[1]))
408					str += 2;
409				fmt_puts(str, &left);
410			} else
411				fmt_puts(*argv, &left);
412		} else
413			fmt_puts(*argv, &left);
62
←
Calling 'fmt_puts'→
414		argv++;
415		fmt_putc(' ', &left);
416	}
417	return;
418nothing:
419	putchar('-')(!__isthreaded ? __sputc('-', (&__sF[1])) : (putc)('-', (
&__sF[1])));
420}
421 
422static void
423pr_header(time_t *nowp, int nusers)
424{
425	double avenrun[3];
426	struct timespec boottime;
427	time_t uptime;
428	int days, hrs, i, mins;
429	char buf[256];
430 
431	/*
432	 * Print time of day.
433	 */
434	(void)strftime(buf, sizeof(buf) - 1, "%l:%M%p", localtime(nowp));
435	buf[sizeof(buf) - 1] = '\0';
436	(void)printf("%s ", buf);
437 
438	/*
439	 * Print how long system has been up.
440	 */
441	if (clock_gettime(CLOCK_BOOTTIME6, &boottime) != -1) {
442		uptime = boottime.tv_sec;
443		if (uptime > 59) {
444			uptime += 30;
445			days = uptime / SECSPERDAY(24 * 60 * 60);
446			uptime %= SECSPERDAY(24 * 60 * 60);
447			hrs = uptime / SECSPERHOUR(60 * 60);
448			uptime %= SECSPERHOUR(60 * 60);
449			mins = uptime / 60;
450			(void)printf(" up");
451			if (days > 0)
452				(void)printf(" %d day%s,", days,
453				    days > 1 ? "s" : "");
454			if (hrs > 0 && mins > 0)
455				(void)printf(" %2d:%02d,", hrs, mins);
456			else {
457				if (hrs > 0)
458					(void)printf(" %d hr%s,",
459					    hrs, hrs > 1 ? "s" : "");
460				if (mins > 0 || (days == 0 && hrs == 0))
461					(void)printf(" %d min%s,",
462					    mins, mins != 1 ? "s" : "");
463			}
464		} else
465			printf(" %d secs,", (int)uptime);
466	}
467 
468	/* Print number of users logged in to system */
469	(void)printf(" %d user%s", nusers, nusers != 1 ? "s" : "");
470 
471	/*
472	 * Print 1, 5, and 15 minute load averages.
473	 */
474	if (getloadavg(avenrun, sizeof(avenrun) / sizeof(avenrun[0])) == -1)
475		(void)printf(", no load average information available\n");
476	else {
477		(void)printf(", load averages:");
478		for (i = 0; i < (sizeof(avenrun) / sizeof(avenrun[0])); i++) {
479			if (i > 0)
480				(void)printf(",");
481			(void)printf(" %.2f", avenrun[i]);
482		}
483		(void)printf("\n");
484	}
485}
486 
487static struct stat *
488ttystat(char *line)
489{
490	static struct stat sb;
491	char ttybuf[sizeof(_PATH_DEV"/dev/") + UT_LINESIZE8];
492 
493	/* Note, line may not be NUL-terminated */
494	(void)strlcpy(ttybuf, _PATH_DEV"/dev/", sizeof(ttybuf));
495	(void)strncat(ttybuf, line, sizeof(ttybuf) - 1 - strlen(ttybuf));
496	if (stat(ttybuf, &sb))
497		return (NULL((void *)0));
498	return (&sb);
499}
500 
501static void
502usage(int wcmd)
503{
504	if (wcmd)
505		(void)fprintf(stderr(&__sF[2]),
506		    "usage: w [-ahi] [-M core] [-N system] [user]\n");
507	else
508		(void)fprintf(stderr(&__sF[2]),
509		    "usage: uptime\n");
510	exit (1);
511}