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 are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #ifndef lint 19 char copyright[] = 20 "@(#) Copyright (c) 1988 Regents of the University of California.\n\ 21 All rights reserved.\n"; 22 #endif /* not lint */ 23 24 #ifndef lint 25 static char sccsid[] = "@(#)wall.c 5.11 (Berkeley) 02/24/90"; 26 #endif /* not lint */ 27 28 /* 29 * This program is not related to David Wall, whose Stanford Ph.D. thesis 30 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 31 */ 32 33 #include <sys/param.h> 34 #include <sys/stat.h> 35 #include <sys/time.h> 36 #include <sys/uio.h> 37 #include <utmp.h> 38 #include <pwd.h> 39 #include <stdio.h> 40 #include <paths.h> 41 42 #define IGNOREUSER "sleeper" 43 44 int nobanner; 45 int mbufsize; 46 char *mbuf; 47 48 /* ARGSUSED */ 49 main(argc, argv) 50 int argc; 51 char **argv; 52 { 53 extern int optind; 54 int ch; 55 struct iovec iov; 56 struct utmp utmp; 57 FILE *fp; 58 char *p, *ttymsg(); 59 60 while ((ch = getopt(argc, argv, "n")) != EOF) 61 switch (ch) { 62 case 'n': 63 /* undoc option for shutdown: suppress banner */ 64 if (geteuid() == 0) 65 nobanner = 1; 66 break; 67 case '?': 68 default: 69 usage: 70 (void)fprintf(stderr, "usage: wall [file]\n"); 71 exit(1); 72 } 73 argc -= optind; 74 argv += optind; 75 if (argc > 1) 76 goto usage; 77 78 makemsg(*argv); 79 80 if (!(fp = fopen(_PATH_UTMP, "r"))) { 81 (void)fprintf(stderr, "wall: cannot read %s.\n", _PATH_UTMP); 82 exit(1); 83 } 84 iov.iov_base = mbuf; 85 iov.iov_len = mbufsize; 86 /* NOSTRICT */ 87 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 88 if (!utmp.ut_name[0] || 89 !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name))) 90 continue; 91 if (p = ttymsg(&iov, 1, utmp.ut_line, 1)) 92 (void)fprintf(stderr, "wall: %s\n", p); 93 } 94 exit(0); 95 } 96 97 makemsg(fname) 98 char *fname; 99 { 100 register int ch, cnt; 101 struct tm *lt; 102 struct passwd *pw, *getpwuid(); 103 struct stat sbuf; 104 time_t now, time(); 105 FILE *fp; 106 int fd; 107 char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15]; 108 char *getlogin(), *malloc(), *strcpy(), *ttyname(); 109 110 (void)strcpy(tmpname, _PATH_TMP); 111 (void)strcat(tmpname, "/wall.XXXXXX"); 112 if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+"))) { 113 (void)fprintf(stderr, "wall: can't open temporary file.\n"); 114 exit(1); 115 } 116 (void)unlink(tmpname); 117 118 if (!nobanner) { 119 if (!(whom = getlogin())) 120 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 121 (void)gethostname(hostname, sizeof(hostname)); 122 (void)time(&now); 123 lt = localtime(&now); 124 125 /* 126 * all this stuff is to blank out a square for the message; 127 * we wrap message lines at column 79, not 80, because some 128 * terminals wrap after 79, some do not, and we can't tell. 129 * Which means that we may leave a non-blank character 130 * in column 80, but that can't be helped. 131 */ 132 (void)fprintf(fp, "\r%79s\r\n", " "); 133 (void)sprintf(lbuf, "Broadcast Message from %s@%s", 134 whom, hostname); 135 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 136 (void)sprintf(lbuf, " (%s) at %d:%02d ...", ttyname(2), 137 lt->tm_hour, lt->tm_min); 138 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 139 } 140 (void)fprintf(fp, "%79s\r\n", " "); 141 142 if (*fname && !(freopen(fname, "r", stdin))) { 143 (void)fprintf(stderr, "wall: can't read %s.\n", fname); 144 exit(1); 145 } 146 while (fgets(lbuf, sizeof(lbuf), stdin)) 147 for (cnt = 0, p = lbuf; ch = *p; ++p, ++cnt) { 148 if (cnt == 79 || ch == '\n') { 149 for (; cnt < 79; ++cnt) 150 putc(' ', fp); 151 putc('\r', fp); 152 putc('\n', fp); 153 cnt = 0; 154 } else 155 putc(ch, fp); 156 } 157 (void)fprintf(fp, "%79s\r\n", " "); 158 rewind(fp); 159 160 if (fstat(fd, &sbuf)) { 161 (void)fprintf(stderr, "wall: can't stat temporary file.\n"); 162 exit(1); 163 } 164 mbufsize = sbuf.st_size; 165 if (!(mbuf = malloc((u_int)mbufsize))) { 166 (void)fprintf(stderr, "wall: out of memory.\n"); 167 exit(1); 168 } 169 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) { 170 (void)fprintf(stderr, "wall: can't read temporary file.\n"); 171 exit(1); 172 } 173 (void)close(fd); 174 } 175