1 /* 2 * Copyright (c) 1988, 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char copyright[] = 10 "@(#) Copyright (c) 1988, 1990, 1993\n\ 11 The Regents of the University of California. All rights reserved.\n"; 12 #endif /* not lint */ 13 14 #ifndef lint 15 static char sccsid[] = "@(#)wall.c 8.1 (Berkeley) 06/06/93"; 16 #endif /* not lint */ 17 18 /* 19 * This program is not related to David Wall, whose Stanford Ph.D. thesis 20 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 21 */ 22 23 #include <sys/param.h> 24 #include <sys/stat.h> 25 #include <sys/time.h> 26 #include <sys/uio.h> 27 #include <utmp.h> 28 #include <pwd.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <paths.h> 32 33 #define IGNOREUSER "sleeper" 34 35 int nobanner; 36 int mbufsize; 37 char *mbuf; 38 39 /* ARGSUSED */ 40 main(argc, argv) 41 int argc; 42 char **argv; 43 { 44 extern int optind; 45 int ch; 46 struct iovec iov; 47 struct utmp utmp; 48 FILE *fp; 49 char *p, *ttymsg(); 50 51 while ((ch = getopt(argc, argv, "n")) != EOF) 52 switch (ch) { 53 case 'n': 54 /* undoc option for shutdown: suppress banner */ 55 if (geteuid() == 0) 56 nobanner = 1; 57 break; 58 case '?': 59 default: 60 usage: 61 (void)fprintf(stderr, "usage: wall [file]\n"); 62 exit(1); 63 } 64 argc -= optind; 65 argv += optind; 66 if (argc > 1) 67 goto usage; 68 69 makemsg(*argv); 70 71 if (!(fp = fopen(_PATH_UTMP, "r"))) { 72 (void)fprintf(stderr, "wall: cannot read %s.\n", _PATH_UTMP); 73 exit(1); 74 } 75 iov.iov_base = mbuf; 76 iov.iov_len = mbufsize; 77 /* NOSTRICT */ 78 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 79 if (!utmp.ut_name[0] || 80 !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name))) 81 continue; 82 if (p = ttymsg(&iov, 1, utmp.ut_line, 60*5)) 83 (void)fprintf(stderr, "wall: %s\n", p); 84 } 85 exit(0); 86 } 87 88 makemsg(fname) 89 char *fname; 90 { 91 register int ch, cnt; 92 struct tm *lt; 93 struct passwd *pw; 94 struct stat sbuf; 95 time_t now, time(); 96 FILE *fp; 97 int fd; 98 char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15]; 99 char *getlogin(), *strcpy(), *ttyname(); 100 101 (void)strcpy(tmpname, _PATH_TMP); 102 (void)strcat(tmpname, "/wall.XXXXXX"); 103 if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+"))) { 104 (void)fprintf(stderr, "wall: can't open temporary file.\n"); 105 exit(1); 106 } 107 (void)unlink(tmpname); 108 109 if (!nobanner) { 110 if (!(whom = getlogin())) 111 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 112 (void)gethostname(hostname, sizeof(hostname)); 113 (void)time(&now); 114 lt = localtime(&now); 115 116 /* 117 * all this stuff is to blank out a square for the message; 118 * we wrap message lines at column 79, not 80, because some 119 * terminals wrap after 79, some do not, and we can't tell. 120 * Which means that we may leave a non-blank character 121 * in column 80, but that can't be helped. 122 */ 123 (void)fprintf(fp, "\r%79s\r\n", " "); 124 (void)sprintf(lbuf, "Broadcast Message from %s@%s", 125 whom, hostname); 126 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 127 (void)sprintf(lbuf, " (%s) at %d:%02d ...", ttyname(2), 128 lt->tm_hour, lt->tm_min); 129 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 130 } 131 (void)fprintf(fp, "%79s\r\n", " "); 132 133 if (fname && !(freopen(fname, "r", stdin))) { 134 (void)fprintf(stderr, "wall: can't read %s.\n", fname); 135 exit(1); 136 } 137 while (fgets(lbuf, sizeof(lbuf), stdin)) 138 for (cnt = 0, p = lbuf; ch = *p; ++p, ++cnt) { 139 if (cnt == 79 || ch == '\n') { 140 for (; cnt < 79; ++cnt) 141 putc(' ', fp); 142 putc('\r', fp); 143 putc('\n', fp); 144 cnt = 0; 145 } else 146 putc(ch, fp); 147 } 148 (void)fprintf(fp, "%79s\r\n", " "); 149 rewind(fp); 150 151 if (fstat(fd, &sbuf)) { 152 (void)fprintf(stderr, "wall: can't stat temporary file.\n"); 153 exit(1); 154 } 155 mbufsize = sbuf.st_size; 156 if (!(mbuf = malloc((u_int)mbufsize))) { 157 (void)fprintf(stderr, "wall: out of memory.\n"); 158 exit(1); 159 } 160 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) { 161 (void)fprintf(stderr, "wall: can't read temporary file.\n"); 162 exit(1); 163 } 164 (void)close(fd); 165 } 166