BSD 4_3_Net_2 release

[unix-history] / usr / src / sbin / dmesg / dmesg.c

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1991 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)dmesg.c     5.9 (Berkeley) 5/2/91";
#endif /* not lint */

#include <sys/cdefs.h>
#include <sys/msgbuf.h>
#include <time.h>
#include <nlist.h>
#include <kvm.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>

struct nlist nl[] = {
#define X_MSGBUF        0
       { "_msgbuf" },
       { NULL },
};

void usage(), vputc();
void err __P((const char *, ...));

main(argc, argv)
       int argc;
       char **argv;
{
       register int ch, newl, skip;
       register char *p, *ep;
       struct msgbuf cur;
       char *core, *namelist;

       core = namelist = NULL;
       while ((ch = getopt(argc, argv, "M:N:")) != EOF)
               switch(ch) {
               case 'M':
                       core = optarg;
                       break;
               case 'N':
                       namelist = optarg;
                       break;
               case '?':
               default:
                       usage();
               }
       argc -= optind;
       argv += optind;

       /* Read in kernel message buffer, do sanity checks. */
       if (kvm_openfiles(namelist, core, NULL) == -1)
               err("kvm_openfiles: %s", kvm_geterr());
       if (kvm_nlist(nl) == -1)
               err("kvm_nlist: %s", kvm_geterr());
       if (nl[X_MSGBUF].n_type == 0)
               err("msgbuf not found namelist");

       kvm_read((void *)nl[X_MSGBUF].n_value, (void *)&cur, sizeof(cur));
       if (cur.msg_magic != MSG_MAGIC)
               err("magic number incorrect");
       if (cur.msg_bufx >= MSG_BSIZE)
               cur.msg_bufx = 0;

       /*
        * The message buffer is circular; start at the read pointer, and
        * go to the write pointer - 1.
        */
       p = cur.msg_bufc + cur.msg_bufx;
       ep = cur.msg_bufc + cur.msg_bufx - 1;
       for (newl = skip = 0; p != ep; ++p) {
               if (p == cur.msg_bufc + MSG_BSIZE)
                       p = cur.msg_bufc;
               ch = *p;
               /* Skip "\n<.*>" syslog sequences. */
               if (skip) {
                       if (ch == '>')
                               newl = skip = 0;
                       continue;
               }
               if (newl && ch == '<') {
                       skip = 1;
                       continue;
               }
               if (ch == '\0')
                       continue;
               newl = (ch = *p) == '\n';
               vputc(ch);
       }
       if (!newl)
               (void)putchar('\n');
       exit(0);
}

void
vputc(ch)
       register int ch;
{
       int meta;

       if (!isascii(ch)) {
               (void)putchar('M');
               (void)putchar('-');
               ch = toascii(ch);
               meta = 1;
       } else
               meta = 0;
       if (isprint(ch) || !meta && (ch == ' ' || ch == '\t' || ch == '\n'))
               (void)putchar(ch);
       else {
               (void)putchar('^');
               (void)putchar(ch == '\177' ? '?' : ch | 0100);
       }
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
       char *fmt;
       va_dcl
#endif
{
       va_list ap;
#if __STDC__
       va_start(ap, fmt);
#else
       va_start(ap);
#endif
       (void)fprintf(stderr, "dmesg: ");
       (void)vfprintf(stderr, fmt, ap);
       va_end(ap);
       (void)fprintf(stderr, "\n");
       exit(1);
       /* NOTREACHED */
}

void
usage()
{
       (void)fprintf(stderr, "usage: dmesg [-M core] [-N system]\n");
       exit(1);
}