msg.c revision 39224
1/*- 2 * Copyright (c) 1998 Andrzej Bialecki <abial@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $Id$ 27 */ 28 29/* 30 * Small replacement for 'dmesg'. It doesn't need libkvm nor /dev/kmem. 31 */ 32 33 34#include <stdio.h> 35#include <sys/types.h> 36#include <sys/sysctl.h> 37 38int 39main(int argc, char *argv[]) 40{ 41 int len,i; 42 char *buf,*p; 43 char *mib="machdep.msgbuf"; 44 45 /* We use sysctlbyname, because the oid is unknown (OID_AUTO) */ 46 47 /* get the buffer size */ 48 i=sysctlbyname(mib,NULL,&len,NULL,NULL); 49 if(i) { 50 perror("buffer sizing"); 51 exit(-1); 52 } 53 buf=(char *)malloc(len*sizeof(char)); 54 i=sysctlbyname(mib,buf,&len,NULL,NULL); 55 if(i) { 56 perror("retrieving data"); 57 exit(-1); 58 } 59 p=buf; 60 i=0; 61 while(p<(buf+len)) { 62 switch(*p) { 63 case '\0': 64 /* skip initial NULLs */ 65 break; 66 default: 67 putchar(*p); 68 } 69 p++; 70 } 71 if(*--p!='\n') putchar('\n'); 72 free(buf); 73 exit(0); 74} 75