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wall.c revision 1.18
      1  1.18       mjl /*	$NetBSD: wall.c,v 1.18 2001/01/05 04:06:49 mjl Exp $	*/
      2   1.6       jtc 
      3   1.1       cgd /*
      4   1.6       jtc  * Copyright (c) 1988, 1990, 1993
      5   1.6       jtc  *	The Regents of the University of California.  All rights reserved.
      6   1.1       cgd  *
      7   1.1       cgd  * Redistribution and use in source and binary forms, with or without
      8   1.1       cgd  * modification, are permitted provided that the following conditions
      9   1.1       cgd  * are met:
     10   1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     11   1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     12   1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     13   1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     14   1.1       cgd  *    documentation and/or other materials provided with the distribution.
     15   1.1       cgd  * 3. All advertising materials mentioning features or use of this software
     16   1.1       cgd  *    must display the following acknowledgement:
     17   1.1       cgd  *	This product includes software developed by the University of
     18   1.1       cgd  *	California, Berkeley and its contributors.
     19   1.1       cgd  * 4. Neither the name of the University nor the names of its contributors
     20   1.1       cgd  *    may be used to endorse or promote products derived from this software
     21   1.1       cgd  *    without specific prior written permission.
     22   1.1       cgd  *
     23   1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24   1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25   1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26   1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27   1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28   1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29   1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30   1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31   1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32   1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33   1.1       cgd  * SUCH DAMAGE.
     34   1.1       cgd  */
     35   1.1       cgd 
     36   1.8  christos #include <sys/cdefs.h>
     37   1.1       cgd #ifndef lint
     38   1.8  christos __COPYRIGHT("@(#) Copyright (c) 1988, 1990, 1993\n\
     39   1.8  christos 	The Regents of the University of California.  All rights reserved.\n");
     40   1.1       cgd #endif /* not lint */
     41   1.1       cgd 
     42   1.1       cgd #ifndef lint
     43   1.6       jtc #if 0
     44   1.6       jtc static char sccsid[] = "@(#)wall.c	8.2 (Berkeley) 11/16/93";
     45   1.6       jtc #endif
     46  1.18       mjl __RCSID("$NetBSD: wall.c,v 1.18 2001/01/05 04:06:49 mjl Exp $");
     47   1.1       cgd #endif /* not lint */
     48   1.1       cgd 
     49   1.1       cgd /*
     50   1.1       cgd  * This program is not related to David Wall, whose Stanford Ph.D. thesis
     51   1.1       cgd  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
     52   1.1       cgd  */
     53   1.1       cgd 
     54   1.1       cgd #include <sys/param.h>
     55   1.1       cgd #include <sys/stat.h>
     56   1.1       cgd #include <sys/time.h>
     57   1.1       cgd #include <sys/uio.h>
     58   1.6       jtc 
     59   1.9     lukem #include <err.h>
     60   1.6       jtc #include <paths.h>
     61   1.1       cgd #include <pwd.h>
     62   1.1       cgd #include <stdio.h>
     63   1.1       cgd #include <stdlib.h>
     64   1.5       jtc #include <string.h>
     65   1.5       jtc #include <unistd.h>
     66   1.6       jtc #include <utmp.h>
     67   1.8  christos #include <util.h>
     68   1.6       jtc 
     69  1.18       mjl void	makemsg(const char *);
     70  1.18       mjl int	main(int, char **);
     71   1.1       cgd 
     72   1.1       cgd int nobanner;
     73   1.1       cgd int mbufsize;
     74   1.1       cgd char *mbuf;
     75   1.1       cgd 
     76   1.1       cgd /* ARGSUSED */
     77   1.5       jtc int
     78  1.18       mjl main(int argc, char **argv)
     79   1.1       cgd {
     80   1.1       cgd 	int ch;
     81   1.1       cgd 	struct iovec iov;
     82   1.1       cgd 	struct utmp utmp;
     83   1.1       cgd 	FILE *fp;
     84   1.8  christos 	char *p;
     85   1.2       cgd 	struct passwd *pep = getpwnam("nobody");
     86   1.6       jtc 	char line[sizeof(utmp.ut_line) + 1];
     87   1.1       cgd 
     88   1.9     lukem 	while ((ch = getopt(argc, argv, "n")) != -1)
     89   1.1       cgd 		switch (ch) {
     90   1.1       cgd 		case 'n':
     91   1.1       cgd 			/* undoc option for shutdown: suppress banner */
     92   1.2       cgd 			if (geteuid() == 0 || (pep && getuid() == pep->pw_uid))
     93   1.1       cgd 				nobanner = 1;
     94   1.1       cgd 			break;
     95   1.1       cgd 		case '?':
     96   1.1       cgd 		default:
     97   1.1       cgd usage:
     98   1.1       cgd 			(void)fprintf(stderr, "usage: wall [file]\n");
     99   1.1       cgd 			exit(1);
    100   1.1       cgd 		}
    101   1.1       cgd 	argc -= optind;
    102   1.1       cgd 	argv += optind;
    103   1.1       cgd 	if (argc > 1)
    104   1.1       cgd 		goto usage;
    105   1.1       cgd 
    106   1.1       cgd 	makemsg(*argv);
    107   1.1       cgd 
    108   1.9     lukem 	if (!(fp = fopen(_PATH_UTMP, "r")))
    109   1.9     lukem 		err(1, "cannot read %s", _PATH_UTMP);
    110   1.1       cgd 	iov.iov_base = mbuf;
    111   1.1       cgd 	iov.iov_len = mbufsize;
    112   1.1       cgd 	/* NOSTRICT */
    113   1.1       cgd 	while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) {
    114  1.17       mjl 		if (!utmp.ut_name[0])
    115   1.1       cgd 			continue;
    116   1.6       jtc 		strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
    117   1.6       jtc 		line[sizeof(utmp.ut_line)] = '\0';
    118   1.6       jtc 		if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL)
    119   1.9     lukem 			warnx("%s", p);
    120   1.1       cgd 	}
    121   1.1       cgd 	exit(0);
    122   1.1       cgd }
    123   1.1       cgd 
    124   1.5       jtc void
    125  1.18       mjl makemsg(const char *fname)
    126   1.1       cgd {
    127   1.1       cgd 	register int ch, cnt;
    128   1.1       cgd 	struct tm *lt;
    129   1.1       cgd 	struct passwd *pw;
    130   1.1       cgd 	struct stat sbuf;
    131   1.8  christos 	time_t now;
    132   1.1       cgd 	FILE *fp;
    133   1.1       cgd 	int fd;
    134  1.11   mycroft 	const char *whom;
    135  1.16      taca 	char *p, *tty, tmpname[32], lbuf[100], hostname[MAXHOSTNAMELEN+1];
    136   1.1       cgd 
    137   1.7       mrg 	(void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP);
    138  1.12  christos 	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
    139   1.9     lukem 		err(1, "can't open temporary file");
    140   1.1       cgd 	(void)unlink(tmpname);
    141   1.1       cgd 
    142   1.1       cgd 	if (!nobanner) {
    143   1.1       cgd 		if (!(whom = getlogin()))
    144   1.1       cgd 			whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
    145   1.1       cgd 		(void)gethostname(hostname, sizeof(hostname));
    146  1.10       mrg 		hostname[sizeof(hostname) - 1] = '\0';
    147   1.1       cgd 		(void)time(&now);
    148   1.1       cgd 		lt = localtime(&now);
    149   1.1       cgd 
    150   1.1       cgd 		/*
    151   1.1       cgd 		 * all this stuff is to blank out a square for the message;
    152   1.1       cgd 		 * we wrap message lines at column 79, not 80, because some
    153   1.1       cgd 		 * terminals wrap after 79, some do not, and we can't tell.
    154   1.1       cgd 		 * Which means that we may leave a non-blank character
    155   1.1       cgd 		 * in column 80, but that can't be helped.
    156   1.1       cgd 		 */
    157   1.1       cgd 		(void)fprintf(fp, "\r%79s\r\n", " ");
    158   1.7       mrg 		(void)snprintf(lbuf, sizeof lbuf,
    159   1.7       mrg 		    "Broadcast Message from %s@%s", whom, hostname);
    160   1.1       cgd 		(void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
    161  1.14      taca 		tty = ttyname(STDERR_FILENO);
    162  1.14      taca 		if (tty == NULL)
    163  1.16      taca 			tty = "??";
    164  1.16      taca 		(void)snprintf(lbuf, sizeof lbuf,
    165  1.16      taca 		    "        (%s) at %d:%02d ...", tty, lt->tm_hour,
    166  1.16      taca 		    lt->tm_min);
    167   1.1       cgd 		(void)fprintf(fp, "%-79.79s\r\n", lbuf);
    168   1.1       cgd 	}
    169   1.1       cgd 	(void)fprintf(fp, "%79s\r\n", " ");
    170   1.1       cgd 
    171   1.9     lukem 	if (fname && !(freopen(fname, "r", stdin)))
    172   1.9     lukem 		err(1, "can't read %s", fname);
    173   1.1       cgd 	while (fgets(lbuf, sizeof(lbuf), stdin))
    174   1.6       jtc 		for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
    175   1.1       cgd 			if (cnt == 79 || ch == '\n') {
    176   1.1       cgd 				for (; cnt < 79; ++cnt)
    177   1.1       cgd 					putc(' ', fp);
    178   1.1       cgd 				putc('\r', fp);
    179   1.1       cgd 				putc('\n', fp);
    180   1.3   mycroft 				cnt = -1;
    181   1.3   mycroft 			}
    182   1.3   mycroft 			if (ch != '\n')
    183   1.1       cgd 				putc(ch, fp);
    184   1.1       cgd 		}
    185   1.1       cgd 	(void)fprintf(fp, "%79s\r\n", " ");
    186   1.1       cgd 	rewind(fp);
    187   1.1       cgd 
    188   1.9     lukem 	if (fstat(fd, &sbuf))
    189   1.9     lukem 		err(1, "can't stat temporary file");
    190   1.1       cgd 	mbufsize = sbuf.st_size;
    191   1.9     lukem 	if (!(mbuf = malloc((u_int)mbufsize)))
    192   1.9     lukem 		err(1, "malloc");
    193   1.9     lukem 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
    194   1.9     lukem 		err(1, "can't read temporary file");
    195   1.1       cgd 	(void)close(fd);
    196   1.1       cgd }
    197