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 8.2 (Berkeley) 11/16/93";
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
28 #include <paths.h>
29 #include <pwd.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <unistd.h>
34 #include <utmp.h>
35
36 void makemsg __P((char *));
37
38 #define IGNOREUSER "sleeper"
39
40 int nobanner;
41 int mbufsize;
42 char *mbuf;
43
44 /* ARGSUSED */
45 int
main(argc,argv)46 main(argc, argv)
47 int argc;
48 char **argv;
49 {
50 extern int optind;
51 int ch;
52 struct iovec iov;
53 struct utmp utmp;
54 FILE *fp;
55 char *p, *ttymsg();
56 char line[sizeof(utmp.ut_line) + 1];
57
58 while ((ch = getopt(argc, argv, "n")) != EOF)
59 switch (ch) {
60 case 'n':
61 /* undoc option for shutdown: suppress banner */
62 if (geteuid() == 0)
63 nobanner = 1;
64 break;
65 case '?':
66 default:
67 usage:
68 (void)fprintf(stderr, "usage: wall [file]\n");
69 exit(1);
70 }
71 argc -= optind;
72 argv += optind;
73 if (argc > 1)
74 goto usage;
75
76 makemsg(*argv);
77
78 if (!(fp = fopen(_PATH_UTMP, "r"))) {
79 (void)fprintf(stderr, "wall: cannot read %s.\n", _PATH_UTMP);
80 exit(1);
81 }
82 iov.iov_base = mbuf;
83 iov.iov_len = mbufsize;
84 /* NOSTRICT */
85 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) {
86 if (!utmp.ut_name[0] ||
87 !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name)))
88 continue;
89 strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
90 line[sizeof(utmp.ut_line)] = '\0';
91 if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL)
92 (void)fprintf(stderr, "wall: %s\n", p);
93 }
94 exit(0);
95 }
96
97 void
makemsg(fname)98 makemsg(fname)
99 char *fname;
100 {
101 register int ch, cnt;
102 struct tm *lt;
103 struct passwd *pw;
104 struct stat sbuf;
105 time_t now, time();
106 FILE *fp;
107 int fd;
108 char *p, *whom, hostname[MAXHOSTNAMELEN], lbuf[100], tmpname[15];
109 char *getlogin(), *strcpy(), *ttyname();
110
111 (void)strcpy(tmpname, _PATH_TMP);
112 (void)strcat(tmpname, "/wall.XXXXXX");
113 if (!(fd = mkstemp(tmpname)) || !(fp = fdopen(fd, "r+"))) {
114 (void)fprintf(stderr, "wall: can't open temporary file.\n");
115 exit(1);
116 }
117 (void)unlink(tmpname);
118
119 if (!nobanner) {
120 if (!(whom = getlogin()))
121 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
122 (void)gethostname(hostname, sizeof(hostname));
123 (void)time(&now);
124 lt = localtime(&now);
125
126 /*
127 * all this stuff is to blank out a square for the message;
128 * we wrap message lines at column 79, not 80, because some
129 * terminals wrap after 79, some do not, and we can't tell.
130 * Which means that we may leave a non-blank character
131 * in column 80, but that can't be helped.
132 */
133 (void)fprintf(fp, "\r%79s\r\n", " ");
134 (void)sprintf(lbuf, "Broadcast Message from %s@%s",
135 whom, hostname);
136 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
137 (void)sprintf(lbuf, " (%s) at %d:%02d ...", ttyname(2),
138 lt->tm_hour, lt->tm_min);
139 (void)fprintf(fp, "%-79.79s\r\n", lbuf);
140 }
141 (void)fprintf(fp, "%79s\r\n", " ");
142
143 if (fname && !(freopen(fname, "r", stdin))) {
144 (void)fprintf(stderr, "wall: can't read %s.\n", fname);
145 exit(1);
146 }
147 while (fgets(lbuf, sizeof(lbuf), stdin))
148 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
149 if (cnt == 79 || ch == '\n') {
150 for (; cnt < 79; ++cnt)
151 putc(' ', fp);
152 putc('\r', fp);
153 putc('\n', fp);
154 cnt = 0;
155 } else
156 putc(ch, fp);
157 }
158 (void)fprintf(fp, "%79s\r\n", " ");
159 rewind(fp);
160
161 if (fstat(fd, &sbuf)) {
162 (void)fprintf(stderr, "wall: can't stat temporary file.\n");
163 exit(1);
164 }
165 mbufsize = sbuf.st_size;
166 if (!(mbuf = malloc((u_int)mbufsize))) {
167 (void)fprintf(stderr, "wall: out of memory.\n");
168 exit(1);
169 }
170 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) {
171 (void)fprintf(stderr, "wall: can't read temporary file.\n");
172 exit(1);
173 }
174 (void)close(fd);
175 }
176