/* parselog.c */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

size_t getfield (char *to, size_t tomaxsize, const char *from, int nfld)
{
    int state;
    const char *p, *plim;
    const char *fldbeg;
    size_t fldlen;
    int fldfound;

    *to= '\0';

    if (!from || !*from || nfld<0) return 0;

    p= from;
    plim= from + strlen (from);
    state= 'A';
    fldfound= 0;
    fldbeg= NULL;
    fldlen= 0;

    for (; fldfound<nfld && p<plim; ++p) {
	int c= *p;

	if (state=='A') {
	    if (!isspace (c)) {
		fldbeg= p;
		state= 'B';
	    }
	} else {
	    if (isspace (c)) {
		fldlen= p-fldbeg;
		++fldfound;
		state= 'A';
	    }
	}
    }
    if (state=='B') {
	fldlen= p-fldbeg;
	++fldfound;
    }

    if (fldfound != nfld) {
	return EOF;

    } else {
	if (fldlen>tomaxsize-1) fldlen= tomaxsize-1;

	memcpy (to, fldbeg, fldlen);
	to[fldlen]= '\0';
	return 0;
    }
}

size_t getprefix (char *to, size_t tomaxsize, const char *from, char separator)
{
    const char *p;
    size_t plen;

    *to= '\0';

    if (!from || !*from) return 0;

    p= strchr (from, separator);
    if (p) plen= p-from;
    else plen= strlen (from);

    if (plen>tomaxsize-1) plen= tomaxsize-1;

    memcpy (to, from, plen);
    to[plen]= '\0';
    return plen;
}

int main (void)
{
    char tmpbuff [24];
    char outbuff [16];

    getfield (tmpbuff, sizeof (tmpbuff)
	, "2-Aug-2012 16:02:54.189 client 192.168.2.4#53554: query: account.thequestionsnetwork.org IN A + (192.168.2.4)"
	, 4);
    getprefix (outbuff, sizeof (outbuff), tmpbuff, '#');
    printf ("Test1: out='%s'\n", outbuff);

    getfield (tmpbuff, sizeof (tmpbuff)
	, "18-Jul-2012 17:18:01.909 client 192.168.2.4#46998: query: apis.google.com IN A + (192.168.2.4)"
	, 4);
    getprefix (outbuff, sizeof (outbuff), tmpbuff, '#');
    printf ("Test2: out='%s'\n", outbuff);

    return 0;
}