1 /* 2 * Copyright (c) 1988, 1990 Regents of the University of California. 3 * 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 35 char copyright[] = 36 "@(#) Copyright (c) 1988 Regents of the University of California.\n\ 37 All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 static char sccsid[] = "@(#)wall.c 5.14 (Berkeley) 3/2/91"; 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 #include <utmp.h> 54 #include <pwd.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <paths.h> 58 59 #define IGNOREUSER "sleeper" 60 61 int nobanner; 62 int mbufsize; 63 char *mbuf; 64 65 /* ARGSUSED */ 66 main(argc, argv) 67 int argc; 68 char **argv; 69 { 70 extern int optind; 71 int ch; 72 struct iovec iov; 73 struct utmp utmp; 74 FILE *fp; 75 char *p, *ttymsg(); 76 struct passwd *pep = getpwnam("nobody"); 77 78 while ((ch = getopt(argc, argv, "n")) != EOF) 79 switch (ch) { 80 case 'n': 81 /* undoc option for shutdown: suppress banner */ 82 if (geteuid() == 0 || (pep && getuid() == pep->pw_uid)) 83 nobanner = 1; 84 break; 85 case '?': 86 default: 87 usage: 88 (void)fprintf(stderr, "usage: wall [file]\n"); 89 exit(1); 90 } 91 argc -= optind; 92 argv += optind; 93 if (argc > 1) 94 goto usage; 95 96 makemsg(*argv); 97 98 if (!(fp = fopen(_PATH_UTMP, "r"))) { 99 (void)fprintf(stderr, "wall: cannot read %s.\n", _PATH_UTMP); 100 exit(1); 101 } 102 iov.iov_base = mbuf; 103 iov.iov_len = mbufsize; 104 /* NOSTRICT */ 105 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 106 if (!utmp.ut_name[0] || 107 !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name))) 108 continue; 109 if (p = ttymsg(&iov, 1, utmp.ut_line)) 110 (void)fprintf(stderr, "wall: %s\n", p); 111 } 112 exit(0); 113 } 114 115 makemsg(fname) 116 char *fname; 117 { 118 register int ch, cnt; 119 struct tm *lt; 120 struct passwd *pw; 121 struct stat sbuf; 122 time_t now, time(); 123 FILE *fp; 124 int fd; 125 char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15]; 126 char *getlogin(), *strcpy(), *ttyname(); 127 128 (void)strcpy(tmpname, _PATH_TMP); 129 (void)strcat(tmpname, "/wall.XXXXXX"); 130 if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+"))) { 131 (void)fprintf(stderr, "wall: can't open temporary file.\n"); 132 exit(1); 133 } 134 (void)unlink(tmpname); 135 136 if (!nobanner) { 137 if (!(whom = getlogin())) 138 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 139 (void)gethostname(hostname, sizeof(hostname)); 140 (void)time(&now); 141 lt = localtime(&now); 142 143 /* 144 * all this stuff is to blank out a square for the message; 145 * we wrap message lines at column 79, not 80, because some 146 * terminals wrap after 79, some do not, and we can't tell. 147 * Which means that we may leave a non-blank character 148 * in column 80, but that can't be helped. 149 */ 150 (void)fprintf(fp, "\r%79s\r\n", " "); 151 (void)sprintf(lbuf, "Broadcast Message from %s@%s", 152 whom, hostname); 153 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 154 (void)sprintf(lbuf, " (%s) at %d:%02d ...", ttyname(2), 155 lt->tm_hour, lt->tm_min); 156 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 157 } 158 (void)fprintf(fp, "%79s\r\n", " "); 159 160 if (fname && !(freopen(fname, "r", stdin))) { 161 (void)fprintf(stderr, "wall: can't read %s.\n", fname); 162 exit(1); 163 } 164 while (fgets(lbuf, sizeof(lbuf), stdin)) 165 for (cnt = 0, p = lbuf; ch = *p; ++p, cnt++) { 166 if (cnt == 79 || ch == '\n') { 167 for (; cnt < 79; ++cnt) 168 putc(' ', fp); 169 putc('\r', fp); 170 putc('\n', fp); 171 cnt = -1; 172 } 173 if (ch != '\n') 174 putc(ch, fp); 175 } 176 (void)fprintf(fp, "%79s\r\n", " "); 177 rewind(fp); 178 179 if (fstat(fd, &sbuf)) { 180 (void)fprintf(stderr, "wall: can't stat temporary file.\n"); 181 exit(1); 182 } 183 mbufsize = sbuf.st_size; 184 if (!(mbuf = malloc((u_int)mbufsize))) { 185 (void)fprintf(stderr, "wall: out of memory.\n"); 186 exit(1); 187 } 188 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) { 189 (void)fprintf(stderr, "wall: can't read temporary file.\n"); 190 exit(1); 191 } 192 (void)close(fd); 193 } 194