1 /* $NetBSD: wall.c,v 1.8 1997/06/29 18:28:20 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1990, 1993 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1988, 1990, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93"; 45 #endif 46 __RCSID("$NetBSD: wall.c,v 1.8 1997/06/29 18:28:20 christos Exp $"); 47 #endif /* not lint */ 48 49 /* 50 * This program is not related to David Wall, whose Stanford Ph.D. thesis 51 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 52 */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 #include <sys/time.h> 57 #include <sys/uio.h> 58 59 #include <paths.h> 60 #include <pwd.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <unistd.h> 65 #include <utmp.h> 66 #include <util.h> 67 68 void makemsg __P((char *)); 69 int main __P((int, char *[])); 70 71 #define IGNOREUSER "sleeper" 72 73 int nobanner; 74 int mbufsize; 75 char *mbuf; 76 77 /* ARGSUSED */ 78 int 79 main(argc, argv) 80 int argc; 81 char **argv; 82 { 83 extern int optind; 84 int ch; 85 struct iovec iov; 86 struct utmp utmp; 87 FILE *fp; 88 char *p; 89 struct passwd *pep = getpwnam("nobody"); 90 char line[sizeof(utmp.ut_line) + 1]; 91 92 while ((ch = getopt(argc, argv, "n")) != EOF) 93 switch (ch) { 94 case 'n': 95 /* undoc option for shutdown: suppress banner */ 96 if (geteuid() == 0 || (pep && getuid() == pep->pw_uid)) 97 nobanner = 1; 98 break; 99 case '?': 100 default: 101 usage: 102 (void)fprintf(stderr, "usage: wall [file]\n"); 103 exit(1); 104 } 105 argc -= optind; 106 argv += optind; 107 if (argc > 1) 108 goto usage; 109 110 makemsg(*argv); 111 112 if (!(fp = fopen(_PATH_UTMP, "r"))) { 113 (void)fprintf(stderr, "wall: cannot read %s.\n", _PATH_UTMP); 114 exit(1); 115 } 116 iov.iov_base = mbuf; 117 iov.iov_len = mbufsize; 118 /* NOSTRICT */ 119 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 120 if (!utmp.ut_name[0] || 121 !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name))) 122 continue; 123 strncpy(line, utmp.ut_line, sizeof(utmp.ut_line)); 124 line[sizeof(utmp.ut_line)] = '\0'; 125 if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL) 126 (void)fprintf(stderr, "wall: %s\n", p); 127 } 128 exit(0); 129 } 130 131 void 132 makemsg(fname) 133 char *fname; 134 { 135 register int ch, cnt; 136 struct tm *lt; 137 struct passwd *pw; 138 struct stat sbuf; 139 time_t now; 140 FILE *fp; 141 int fd; 142 char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15]; 143 144 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 145 if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+"))) { 146 (void)fprintf(stderr, "wall: can't open temporary file.\n"); 147 exit(1); 148 } 149 (void)unlink(tmpname); 150 151 if (!nobanner) { 152 if (!(whom = getlogin())) 153 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 154 (void)gethostname(hostname, sizeof(hostname)); 155 (void)time(&now); 156 lt = localtime(&now); 157 158 /* 159 * all this stuff is to blank out a square for the message; 160 * we wrap message lines at column 79, not 80, because some 161 * terminals wrap after 79, some do not, and we can't tell. 162 * Which means that we may leave a non-blank character 163 * in column 80, but that can't be helped. 164 */ 165 (void)fprintf(fp, "\r%79s\r\n", " "); 166 (void)snprintf(lbuf, sizeof lbuf, 167 "Broadcast Message from %s@%s", whom, hostname); 168 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 169 (void)snprintf(lbuf, sizeof lbuf, " (%s) at %d:%02d ...", 170 ttyname(2), lt->tm_hour, lt->tm_min); 171 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 172 } 173 (void)fprintf(fp, "%79s\r\n", " "); 174 175 if (fname && !(freopen(fname, "r", stdin))) { 176 (void)fprintf(stderr, "wall: can't read %s.\n", fname); 177 exit(1); 178 } 179 while (fgets(lbuf, sizeof(lbuf), stdin)) 180 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 181 if (cnt == 79 || ch == '\n') { 182 for (; cnt < 79; ++cnt) 183 putc(' ', fp); 184 putc('\r', fp); 185 putc('\n', fp); 186 cnt = -1; 187 } 188 if (ch != '\n') 189 putc(ch, fp); 190 } 191 (void)fprintf(fp, "%79s\r\n", " "); 192 rewind(fp); 193 194 if (fstat(fd, &sbuf)) { 195 (void)fprintf(stderr, "wall: can't stat temporary file.\n"); 196 exit(1); 197 } 198 mbufsize = sbuf.st_size; 199 if (!(mbuf = malloc((u_int)mbufsize))) { 200 (void)fprintf(stderr, "wall: out of memory.\n"); 201 exit(1); 202 } 203 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) { 204 (void)fprintf(stderr, "wall: can't read temporary file.\n"); 205 exit(1); 206 } 207 (void)close(fd); 208 } 209