wall.c revision 50772 
1/*
2 * Copyright (c) 1988, 1990, 1993
3 *	The Regents of the University of California.  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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1988, 1990, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)wall.c	8.2 (Berkeley) 11/16/93";
43#endif
44static const char rcsid[] =
45  "$FreeBSD: head/usr.bin/wall/wall.c 50772 1999-09-01 22:21:24Z dbaker $";
46#endif /* not lint */
47
48/*
49 * This program is not related to David Wall, whose Stanford Ph.D. thesis
50 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
51 */
52
53#include <sys/param.h>
54#include <sys/stat.h>
55#include <sys/uio.h>
56
57#include <ctype.h>
58#include <err.h>
59#include <locale.h>
60#include <paths.h>
61#include <pwd.h>
62#include <stdio.h>
63#include <stdlib.h>
64#include <string.h>
65#include <time.h>
66#include <unistd.h>
67#include <utmp.h>
68
69void	makemsg __P((char *));
70static void usage __P((void));
71
72#define	IGNOREUSER	"sleeper"
73
74int nobanner;
75int mbufsize;
76char *mbuf;
77
78/* ARGSUSED */
79int
80main(argc, argv)
81	int argc;
82	char **argv;
83{
84	int ch;
85	struct iovec iov;
86	struct utmp utmp;
87	FILE *fp;
88	char *p, *ttymsg();
89	char line[sizeof(utmp.ut_line) + 1];
90
91	(void)setlocale(LC_CTYPE, "");
92
93	while ((ch = getopt(argc, argv, "n")) != -1)
94		switch (ch) {
95		case 'n':
96			/* undoc option for shutdown: suppress banner */
97			if (geteuid() == 0)
98				nobanner = 1;
99			break;
100		case '?':
101		default:
102			usage();
103		}
104	argc -= optind;
105	argv += optind;
106	if (argc > 1)
107		usage();
108
109	makemsg(*argv);
110
111	if (!(fp = fopen(_PATH_UTMP, "r")))
112		errx(1, "cannot read %s", _PATH_UTMP);
113	iov.iov_base = mbuf;
114	iov.iov_len = mbufsize;
115	/* NOSTRICT */
116	while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) {
117		if (!utmp.ut_name[0] ||
118		    !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name)))
119			continue;
120		strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
121		line[sizeof(utmp.ut_line)] = '\0';
122		if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL)
123			warnx("%s", p);
124	}
125	exit(0);
126}
127
128static void
129usage()
130{
131	(void)fprintf(stderr, "usage: wall [file]\n");
132	exit(1);
133}
134
135void
136makemsg(fname)
137	char *fname;
138{
139	register int cnt;
140	register unsigned char ch;
141	struct tm *lt;
142	struct passwd *pw;
143	struct stat sbuf;
144	time_t now;
145	FILE *fp;
146	int fd;
147	char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
148
149	snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
150
151	if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+")))
152		errx(1, "can't open temporary file");
153	(void)unlink(tmpname);
154
155	if (!nobanner) {
156		if (!(whom = getlogin()))
157			whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
158		(void)gethostname(hostname, sizeof(hostname));
159		(void)time(&now);
160		lt = localtime(&now);
161
162		/*
163		 * all this stuff is to blank out a square for the message;
164		 * we wrap message lines at column 79, not 80, because some
165		 * terminals wrap after 79, some do not, and we can't tell.
166		 * Which means that we may leave a non-blank character
167		 * in column 80, but that can't be helped.
168		 */
169		(void)fprintf(fp, "\r%79s\r\n", " ");
170		(void)snprintf(lbuf, sizeof(lbuf),
171		    "Broadcast Message from %s@%s",
172		    whom, hostname);
173		(void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
174		(void)snprintf(lbuf, sizeof(lbuf),
175		    "        (%s) at %d:%02d ...", ttyname(2),
176		    lt->tm_hour, lt->tm_min);
177		(void)fprintf(fp, "%-79.79s\r\n", lbuf);
178	}
179	(void)fprintf(fp, "%79s\r\n", " ");
180
181	if (fname && !(freopen(fname, "r", stdin)))
182		errx(1, "can't read %s", fname);
183	while (fgets(lbuf, sizeof(lbuf), stdin))
184		for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
185			if (cnt == 79 || ch == '\n') {
186				for (; cnt < 79; ++cnt)
187					putc(' ', fp);
188				putc('\r', fp);
189				putc('\n', fp);
190				cnt = 0;
191			} else if (((ch & 0x80) && ch < 0xA0) ||
192				   /* disable upper controls */
193				   (!isprint(ch) && !isspace(ch) &&
194				    ch != '\a' && ch != '\b')
195				  ) {
196				if (ch & 0x80) {
197					ch &= 0x7F;
198					putc('M', fp);
199					if (++cnt == 79) {
200						putc('\r', fp);
201						putc('\n', fp);
202						cnt = 0;
203					}
204					putc('-', fp);
205					if (++cnt == 79) {
206						putc('\r', fp);
207						putc('\n', fp);
208						cnt = 0;
209					}
210				}
211				if (iscntrl(ch)) {
212					ch ^= 040;
213					putc('^', fp);
214					if (++cnt == 79) {
215						putc('\r', fp);
216						putc('\n', fp);
217						cnt = 0;
218					}
219				}
220			} else {
221				putc(ch, fp);
222			}
223		}
224	(void)fprintf(fp, "%79s\r\n", " ");
225	rewind(fp);
226
227	if (fstat(fd, &sbuf))
228		errx(1, "can't stat temporary file");
229	mbufsize = sbuf.st_size;
230	if (!(mbuf = malloc((u_int)mbufsize)))
231		errx(1, "out of memory");
232	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
233		errx(1, "can't read temporary file");
234	(void)close(fd);
235}
236