3 * Jeff Wheelhouse (jdw@wwwi.com)
5 * This code was originally developed by Jeff Wheelhouse (jdw@wwwi.com).
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistribution of source code must retail the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY JEFF WHEELHOUSE ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
19 * NO EVENT SHALL JEFF WHEELHOUSE BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
22 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
23 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
24 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
25 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 * $Id: clog.c,v 1.3 2001/10/02 18:51:26 jdw Exp $
42 #include <sys/sched.h>
51 * The BUFFER_SIZE value is just used to allocate a buffer full of NULLs
52 * so that a new logfile can be extended to its full size.
54 * Compiling with -pedantic complains when the buffer array is declared
55 * if I declare this as a const instead of a #define.
57 #define BUFFER_SIZE 16384
59 static void init_log(const char *lname, size_t size);
60 static void read_log(const char *lname, int optf);
61 static void usage(void);
63 static const char *pname;
66 main(int argc, char **argv)
75 while ((ch = getopt(argc, argv, "fis:")) != -1)
88 if ((size>0)&&(init==0)) {
89 fprintf(stderr,"%s: WARNING: -s argument ignored without -i.\n",pname);
92 if (argv[optind]==NULL) {
93 fprintf(stderr,"%s: ERROR: log_file argument must be specified.\n",pname);
96 if ((init==1)&&(size==0)) {
97 fprintf(stderr,"%s: ERROR: -i argument requires -s.\n",pname);
100 if ((init==1)&&(optf==1)) {
101 fprintf(stderr,"%s: ERROR: flags -f and -i are incompatible.\n",pname);
105 if (init==1) init_log(argv[optind],size);
106 /* if (optf==1) follow_log(artv[optind]); */
107 read_log(argv[optind],optf);
116 fprintf(stderr,"usage: %s [-i -s log_size] [ -f ] log_file\n",pname);
122 read_log(const char *lname, int optf)
126 struct clog_footer *pcf;
136 fd = open(lname,O_RDONLY);
138 fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno));
142 if (fstat(fd,&sb)==-1) {
143 fprintf(stderr,"%s: ERROR: could not stat %s (%s)\n",pname,lname,strerror(errno));
146 pbuffer = mmap(NULL,sb.st_size,PROT_READ,MAP_SHARED,fd,0);
148 fprintf(stderr,"%s: ERROR: could not mmap %s body (%s)\n",pname,lname,strerror(errno));
151 pcf = (struct clog_footer*)(pbuffer + sb.st_size - sizeof(struct clog_footer));
153 if (pcf->cf_wrap==1) start = pcf->cf_next + 1;
155 while(pcf->cf_lock==1) sched_yield();
159 iov[iovcnt].iov_base = pbuffer + start;
160 iov[iovcnt++].iov_len = pcf->cf_max - start;
163 iov[iovcnt].iov_base = pbuffer + start;
164 iov[iovcnt++].iov_len = next - start;
165 if (writev(1,iov,iovcnt)==-1) {
166 fprintf(stderr,"%s: ERROR: could not write output (%s)\n",pname,strerror(errno));
171 if (poll(&pfd,1,50)==-1) {
172 fprintf(stderr,"%s: ERROR: could not poll (%s)\n",pname,strerror(errno));
177 munmap(pbuffer,sb.st_size);
185 init_log(const char *lname, size_t size)
189 char buffer[BUFFER_SIZE];
190 struct clog_footer cf;
192 memcpy(&cf.cf_magic,MAGIC_CONST,4);
193 cf.cf_max = size - sizeof(struct clog_footer);
195 memset(buffer,0,BUFFER_SIZE);
197 fd = open(lname,O_RDWR|O_CREAT,0666);
199 fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno));
202 if (ftruncate(fd,(off_t)0)==-1) {
203 fprintf(stderr,"%s: ERROR: could not truncate %s (%s)\n",pname,lname,strerror(errno));
207 while(fill>BUFFER_SIZE) {
208 if (write(fd,buffer,BUFFER_SIZE)==-1){
209 fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno));
214 assert(fill<=BUFFER_SIZE);
216 if (write(fd,buffer,fill)==-1) {
217 fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno));
221 if (lseek(fd,-(off_t)(sizeof(struct clog_footer)),SEEK_END)==-1) {
222 fprintf(stderr,"%s: ERROR: could not seek in %s (%s)\n",pname,lname,strerror(errno));
225 if (write(fd,&cf,sizeof(cf))==-1) {
226 fprintf(stderr,"%s: ERROR: could not write magic in %s (%s)\n",pname,lname,strerror(errno));