#include <stdlib.h>		// for exit
#include <unistd.h>		// for getopt
#include <stdio.h>		// for printf, fprintf, fflush
#include <string.h>		// for strtok, memset, memcpy
#include <ctype.h>		// for isdigit

//
// Purpose:	Homework 1, Problem 3
// Usage:	hw1-3 < Command
// Comment:
//   o	This is a minimalistic solution based on hw1-3.c which is a pedagogic
//	version.
// History:
//	14 sep 2006	kenw, creation
//

// --| constants |--
const int	MAX_LINE = 50;
const int	BUFSZ = 100;
const char	*WHITE = " \t\n";       // white space characters

// --| prototypes |--
int getTokens(char *cmnd, char *word[], const char *delim);
void pkbuf0(int seqnum, int nwords, char *word[]);

// --| globals |--

// --| defines |--
#define DEBUG(arglst)	fprintf arglst;

int
main (int argc, char *argv[]) {
  char	cmnd[MAX_LINE];	// command-line
  char	*word[BUFSZ];	// word[k] points to kth word
  int	nwords;		// #words in command line
  int	seqnum = 0;
  int	i;

  while (fgets(cmnd, MAX_LINE, stdin) != NULL) {
    if (cmnd[strlen(cmnd)-1] != '\n') {
      fprintf(stderr, "*** Ooops, line too long\n");
      exit(1);
    }
    // for (i=0; (i<MAX_LINE) && (cmnd[i] != '\0'); i++) {
    //   printf(" %02x", cmnd[i]);
    // }
    // printf("\n");
    printf("%s", cmnd);		fflush(stdout);
    nwords = getTokens(cmnd, word, WHITE);

    pkbuf0(seqnum, nwords, word);

    printf("\n"); fflush(stdout);
    ++seqnum;
    if (strcmp(word[0], "quit") == 0)	break;
  }
  return 0;

}

// --| get tokens |--
int
getTokens(char *cmnd, char *word[], const char *delim) {
  int	nwords = 0;
  char	*p = cmnd;
  char	*token;

  while ((token=strtok(p,delim)) != NULL) {
    word[nwords] = token;
    //XXX DEBUG( (stderr, "\tword[%d] = %s\n", nwords, token) );
    nwords++;
    p = NULL;
  }
  word[nwords] = NULL;
  return nwords;
}

// --| pack buffer using ptr casting |--
//
// Buffer Structure:
//	  int	seqnum;
//	  char	*str_ptr[nwords];
//	  char	str[BUFSZ-sizeof(seqnum)-nwords*sizeof(char *)];
//
void
pkbuf0(int seqnum, int nwords, char *word[]) {
  char	buf[BUFSZ];	// our buffer
  int	*sn_ptr;	// ptr to seqnum
  char	**str_ptr, **str_ptr_save;	// ptr to char ptr
  char	*str;		// ptr to char str
  int	str_offset;	// index to beginning of strings
  int	i;

  str_offset = sizeof(seqnum) + (nwords+1)*sizeof(char *);
  str = buf + str_offset;
  str_ptr_save = str_ptr = (char **) (buf + sizeof(seqnum));
  sn_ptr = (int *)buf;

  memset(buf, 0x0, BUFSZ);			// zero buffer
  *sn_ptr = seqnum;
  for (i=0; i<nwords; i++) {
    strcpy(str, word[i]);
    *(str_ptr) = str;
    str += (1+strlen(word[i]));
    ++str_ptr;
  }
  *(str_ptr) = 0;		// null ptr
  
  printf("buf (verbose):\n");
  printf("%3d ", *sn_ptr);
  str_ptr = str_ptr_save;
  for (i=0; i<nwords; i++) {
    printf("%p ", *str_ptr);
    ++str_ptr;
  }
  printf("%p ", *str_ptr);

  str_ptr = str_ptr_save;
  for (i=0; i<nwords; i++) {
    str = *str_ptr;
    while (*str != 0)	printf("%02x ", (u_char) *str++);
    printf("%x ", (u_char) *str);
    ++str_ptr;
  }
  printf("\n");
  fflush(stdout);
}