wall.c revision 24729
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 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 41static char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93"; 42#endif /* not lint */ 43 44/* 45 * This program is not related to David Wall, whose Stanford Ph.D. thesis 46 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 47 */ 48 49#include <sys/param.h> 50#include <sys/stat.h> 51#include <sys/time.h> 52#include <sys/uio.h> 53 54#include <paths.h> 55#include <pwd.h> 56#include <stdio.h> 57#include <stdlib.h> 58#include <string.h> 59#include <unistd.h> 60#include <utmp.h> 61 62void makemsg __P((char *)); 63 64#define IGNOREUSER "sleeper" 65 66int nobanner; 67int mbufsize; 68char *mbuf; 69 70/* ARGSUSED */ 71int 72main(argc, argv) 73 int argc; 74 char **argv; 75{ 76 extern int optind; 77 int ch; 78 struct iovec iov; 79 struct utmp utmp; 80 FILE *fp; 81 char *p, *ttymsg(); 82 char line[sizeof(utmp.ut_line) + 1]; 83 84 while ((ch = getopt(argc, argv, "n")) != -1) 85 switch (ch) { 86 case 'n': 87 /* undoc option for shutdown: suppress banner */ 88 if (geteuid() == 0) 89 nobanner = 1; 90 break; 91 case '?': 92 default: 93usage: 94 (void)fprintf(stderr, "usage: wall [file]\n"); 95 exit(1); 96 } 97 argc -= optind; 98 argv += optind; 99 if (argc > 1) 100 goto usage; 101 102 makemsg(*argv); 103 104 if (!(fp = fopen(_PATH_UTMP, "r"))) { 105 (void)fprintf(stderr, "wall: cannot read %s.\n", _PATH_UTMP); 106 exit(1); 107 } 108 iov.iov_base = mbuf; 109 iov.iov_len = mbufsize; 110 /* NOSTRICT */ 111 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 112 if (!utmp.ut_name[0] || 113 !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name))) 114 continue; 115 strncpy(line, utmp.ut_line, sizeof(utmp.ut_line)); 116 line[sizeof(utmp.ut_line)] = '\0'; 117 if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL) 118 (void)fprintf(stderr, "wall: %s\n", p); 119 } 120 exit(0); 121} 122 123void 124makemsg(fname) 125 char *fname; 126{ 127 register int cnt; 128 register unsigned char ch; 129 struct tm *lt; 130 struct passwd *pw; 131 struct stat sbuf; 132 time_t now, time(); 133 FILE *fp; 134 int fd; 135 char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15]; 136 char *getlogin(), *strcpy(), *ttyname(); 137 138 (void)strcpy(tmpname, _PATH_TMP); 139 (void)strcat(tmpname, "/wall.XXXXXX"); 140 if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+"))) { 141 (void)fprintf(stderr, "wall: can't open temporary file.\n"); 142 exit(1); 143 } 144 (void)unlink(tmpname); 145 146 if (!nobanner) { 147 if (!(whom = getlogin())) 148 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 149 (void)gethostname(hostname, sizeof(hostname)); 150 (void)time(&now); 151 lt = localtime(&now); 152 153 /* 154 * all this stuff is to blank out a square for the message; 155 * we wrap message lines at column 79, not 80, because some 156 * terminals wrap after 79, some do not, and we can't tell. 157 * Which means that we may leave a non-blank character 158 * in column 80, but that can't be helped. 159 */ 160 (void)fprintf(fp, "\r%79s\r\n", " "); 161 (void)sprintf(lbuf, "Broadcast Message from %s@%s", 162 whom, hostname); 163 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 164 (void)sprintf(lbuf, " (%s) at %d:%02d ...", ttyname(2), 165 lt->tm_hour, lt->tm_min); 166 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 167 } 168 (void)fprintf(fp, "%79s\r\n", " "); 169 170 if (fname && !(freopen(fname, "r", stdin))) { 171 (void)fprintf(stderr, "wall: can't read %s.\n", fname); 172 exit(1); 173 } 174 while (fgets(lbuf, sizeof(lbuf), stdin)) 175 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 176 again: 177 if (cnt == 79 || ch == '\n') { 178 for (; cnt < 79; ++cnt) 179 putc(' ', fp); 180 putc('\r', fp); 181 putc('\n', fp); 182 cnt = 0; 183 } else if ( !isprint(ch) && !isspace(ch) 184 && ch != '\007' && ch != '\010' 185 ) { 186 if (ch & 0x80) { 187 ch &= 0x7F; 188 (void)fprintf(fp, "M-"); 189 goto again; 190 } 191 putc('^', fp); 192 putc(ch^0x40, fp); /* DEL to ?, others to alpha */ 193 } else 194 putc(ch, fp); 195 } 196 (void)fprintf(fp, "%79s\r\n", " "); 197 rewind(fp); 198 199 if (fstat(fd, &sbuf)) { 200 (void)fprintf(stderr, "wall: can't stat temporary file.\n"); 201 exit(1); 202 } 203 mbufsize = sbuf.st_size; 204 if (!(mbuf = malloc((u_int)mbufsize))) { 205 (void)fprintf(stderr, "wall: out of memory.\n"); 206 exit(1); 207 } 208 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) { 209 (void)fprintf(stderr, "wall: can't read temporary file.\n"); 210 exit(1); 211 } 212 (void)close(fd); 213} 214