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

#define MAXWORDS       32000
#define MAXWORDLEN     32
#define DICTFILENAME   "/usr/lib/dict/words"
#define MATCH_ANY      '?'

#define FALSE          0
#define TRUE           1

typedef int BOOL;
typedef char word_type[MAXWORDLEN];
typedef word_type dict_type[MAXWORDS];

int
read_dict_file(char *filename, dict_type dict)
{
  int numwords;
  FILE *infile;

  infile = fopen(filename, "r");
  if (infile == NULL) {
    fprintf(stderr, "Could not open file `%s'\n", filename);
    exit(EXIT_FAILURE);
  }
  numwords = 0;
  while (numwords < MAXWORDS &&
         fgets(dict[numwords], MAXWORDLEN, infile) != NULL)
    numwords++;
  fclose(infile);
  return(numwords);
}

BOOL
match_word(word_type pattern, word_type word)
{
  int i;

  if (strlen(pattern) != strlen(word))
    return(FALSE);
  for (i = 0; i < strlen(pattern); i++)
    if (pattern[i] != word[i] && pattern[i] != MATCH_ANY)
      return(FALSE);
  return(TRUE);
}

void
match_dict(word_type pattern, dict_type dict, int numwords)
{
  int i;
  BOOL found_a_match;

  found_a_match = FALSE;
  for (i = 0; i < numwords; i++)
    if (match_word(pattern, dict[i])) {
      printf("%s", dict[i]);
      found_a_match = TRUE;
    }
  if (!found_a_match)
    printf("No words were found that match %s", pattern);
}



main()
{
  dict_type dict;
  int numwords;
  word_type pattern;

  numwords = read_dict_file(DICTFILENAME, dict);
  for (;;) {
    printf("Please enter a pattern: ");
    fflush(stdout);
    if (fgets(pattern, MAXWORDLEN, stdin) == NULL)
      break;
    match_dict(pattern, dict, numwords);
  }
  printf("\nGoodbye.\n");
}