如何阅读源代码
os) ) *cp2++ = *cp1++;
*cp2 = '';
if (*cp1 != '')
{
if (verbose)
{
fprintf(stderr,"%s",msg_big_date);
if (debug_mode) fprintf(stderr,": %s ",cpx);
else fprintf(stderr," ");
}
while (*cp1 != '') cp1++;
}
if (cp1 < eob) cp1++;
/* minimal sanity check on timestamp */
if ( (log_rec.datetime[0] != '[') ||
(log_rec.datetime[3] != '/') ||
(cp1 >= eob)) return 0;
/* HTTP request */
cpx = cp1;
cp2 = log_rec.url;
eos = (cp1+MAXURL-1);
if (eos >= eob) eos = eob-1;
while ( (*cp1 != '') && (cp1 != eos) ) *cp2++ = *cp1++;
*cp2 = '';
if (*cp1 != '')
{
if (verbose)
{
fprintf(stderr,"%s",msg_big_req);
if (debug_mode) fprintf(stderr,": %s ",cpx);
else fprintf(stderr," ");
}
while (*cp1 != '') cp1++;
}
if (cp1 < eob) cp1++;
if ( (log_rec.url[0] != '"') ||
(cp1 >= eob) ) return 0;
/* response code */
log_rec.resp_code = atoi(cp1);
/* xfer size */
while ( (*cp1 != '') && (cp1 < eob) ) cp1++;
if (cp1 < eob) cp1++;
if (*cp1<'0'||*cp1>'9') log_rec.xfer_size=0;
else log_rec.xfer_size = strtoul(cp1,NULL,10);
/* done with CLF record */
if (cp1>=eob) return 1;
while ( (*cp1 != '') && (*cp1 != ' ') && (cp1 < eob) ) cp1++;
if (cp1 < eob) cp1++;
/* get referrer if present */
cpx = cp1;
cp2 = log_rec.refer;
eos = (cp1+MAXREF-1);
if (eos >= eob) eos = eob-1;
while ( (*cp1 != '') && (*cp1 != ' ') && (cp1 != eos) ) *cp2++ = *cp1++;
*cp2 = '';
if (*cp1 != '')
{
if (verbose)
{
fprintf(stderr,"%s",msg_big_ref);
if (debug_mode) fprintf(stderr,": %s ",cpx);
else fprintf(stderr," ");
}
while (*cp1 != '') cp1++;
}
if (cp1 < eob) cp1++;
cpx = cp1;
cp2 = log_rec.agent;
eos = cp1+(MAXAGENT-1);
if (eos >= eob) eos = eob-1;
while ( (*cp1 != '') && (cp1 != eos) ) *cp2++ = *cp1++;
*cp2 = '';
return 1; /* maybe a valid record, return with TRUE */
}
该函数，一次读入一行（其实是一段日志数据中间的一个域，因为该行数据已经被fmt_logrec分开成多行数据了。根据CLF中的定义，检查该数据并将其拷贝到log_rec结构中去，如果检查该数据有效，则返回1。回到主程序,
/* convert month name to lowercase */
for (i=4;i<7;i++)
log_rec.datetime[i]=tolower(log_rec.datetime[i]);
/* get year/month/day/hour/min/sec values */
for (i=0;i<12;i++)
{
if (strncmp(log_month[i],&log_rec.datetime[4],3)==0)
{ rec_month = i+1; break; }
}
rec_year=atoi(&log_rec.datetime[8]); /
* get year number (int) */
rec_day =atoi(&log_rec.datetime[1]); /* get day number */
rec_hour=atoi(&log_rec.datetime[13]); /* get hour