2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
35 static const char copyright[] =
36 "@(#) Copyright (c) 1991, 1993\n\
37 The Regents of the University of California. All rights reserved.\n";
42 static const char sccsid[] = "@(#)dmesg.c 8.1 (Berkeley) 6/5/93";
44 static const char rcsid[] =
45 "$FreeBSD: src/sbin/dmesg/dmesg.c,v 1.11.2.3 2001/08/08 22:32:15 obrien Exp $";
48 #include <sys/types.h>
49 #include <sys/msgbuf.h>
50 #include <sys/sysctl.h>
60 #include <sys/syslog.h>
68 void usage __P((void));
70 #define KREAD(addr, var) \
71 kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var)
80 struct msgbuf *bufp, cur;
81 char *bp, *memf, *nlistf;
89 (void) setlocale(LC_CTYPE, "");
91 while ((ch = getopt(argc, argv, "aM:N:")) != -1)
109 if (memf == NULL && nlistf == NULL) {
110 /* Running kernel. Use sysctl. */
111 if (sysctlbyname("kern.msgbuf", NULL, &buflen, NULL, 0) == -1)
112 err(1, "sysctl kern.msgbuf");
113 if ((bp = malloc(buflen)) == NULL)
114 errx(1, "malloc failed");
115 if (sysctlbyname("kern.msgbuf", bp, &buflen, NULL, 0) == -1)
116 err(1, "sysctl kern.msgbuf");
117 /* We get a dewrapped buffer using sysctl. */
120 /* Read in kernel message buffer, do sanity checks. */
121 kd = kvm_open(nlistf, memf, NULL, O_RDONLY, "dmesg");
124 if (kvm_nlist(kd, nl) == -1)
125 errx(1, "kvm_nlist: %s", kvm_geterr(kd));
126 if (nl[X_MSGBUF].n_type == 0)
127 errx(1, "%s: msgbufp not found",
128 nlistf ? nlistf : "namelist");
129 if (KREAD(nl[X_MSGBUF].n_value, bufp) || KREAD((long)bufp, cur))
130 errx(1, "kvm_read: %s", kvm_geterr(kd));
131 if (cur.msg_magic != MSG_MAGIC)
132 errx(1, "kernel message buffer has different magic "
134 bp = malloc(cur.msg_size);
136 errx(1, "malloc failed");
137 if (kvm_read(kd, (long)cur.msg_ptr, bp, cur.msg_size) !=
139 errx(1, "kvm_read: %s", kvm_geterr(kd));
141 buflen = cur.msg_size;
142 bufpos = cur.msg_bufx;
143 if (bufpos >= buflen)
148 * The message buffer is circular. If the buffer has wrapped, the
149 * write pointer points to the oldest data. Otherwise, the write
150 * pointer points to \0's following the data. Read the entire
151 * buffer starting at the write pointer and ignore nulls so that
152 * we effectively start at the oldest data.
155 ep = (bufpos == 0 ? bp + buflen : p);
158 if (p == bp + buflen)
161 /* Skip "\n<.*>" syslog sequences. */
167 if (LOG_FAC(pri) == LOG_KERN || all)
169 } else if (ch >= '0' && ch <= '9') {
175 if (newl && ch == '<') {
183 (void)vis(buf, ch, 0, 0);
185 (void)putchar(buf[0]);
187 (void)printf("%s", buf);
197 (void)fprintf(stderr, "usage: dmesg [-a] [-M core] [-N system]\n");