#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( u_long code, int nwords, char *word[] );
u_long get_code( char *keyword );

// --| 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		i;
    int		code;

    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 );

	code = get_code( word[0] );
	if( code != -1 ) {
	    pkbuf0( (u_long) code, nwords-1, &word[1] );
	    printf( "\n" ); fflush( stdout );
	}

	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:
//	  char	*str_ptr[nwords];
//	  char	str[BUFSZ-sizeof(code)-nwords*sizeof(char *)];
//
void
pkbuf0( u_long code, int nwords, char *word[] ) {
    char	buf[BUFSZ];	// our buffer
    u_long	*code_ptr;	// ptr to code
    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(u_long) + (nwords+1)*sizeof(char *);
    str = buf + str_offset;
    str_ptr_save = str_ptr = (char **) ( buf + sizeof(u_long) );
    code_ptr = (u_long *)buf;

    memset( buf, 0x0, BUFSZ );			// zero buffer
    *code_ptr = code;
    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 (%p):\n", buf );
    printf( "%3d ", *code_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 );
}

// Return keyword code; -1 if not a keyword
//
u_long
get_code( char *keyword ) {
    if( strcmp(keyword, "spawn" ) == 0 )	return 1;
    else if( strcmp(keyword, "wait" ) == 0 )	return 2;
    else if( strcmp(keyword, "send" ) == 0 )	return 3;
    else					return -1;
}