#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

/*
 * mmm    (In the style of Homer Simpson)  Kees Cook 1997
 *
 *        Picks psudo-random words from the dictionary
 */

main(int argc, char * argv[0]) {
  int fd;
  struct stat st;
  struct timeval tv;
  char *base, *ptr;
  int offset,loops;

  gettimeofday(&tv,NULL);
  srand(tv.tv_sec * 1000 + tv.tv_usec);

  if ((fd=open("/usr/dict/words", O_RDONLY,0)) < 0) {
    perror("open");
    exit(1);
  }
  fstat(fd,&st);  /* Get the size */

  if ((int)(base=(char *)mmap(0,st.st_size,PROT_READ,MAP_SHARED,fd,0)) == -1) {
    perror("mmap");
    exit(1);
  }
  close(fd);  /* Now we can get to it via pointers */

  /* if the argument is a number use that many words, otherwise 1 */
  if (argc < 2 || (loops=atoi(argv[1]))==0) loops=1;

  for (;loops>0;loops--) {

	  /* get a random offset within the size of the file */
	  /* (this assumes your max rand is bigger than your file size) */
	  while((offset=rand()) >= st.st_size) ;

	  /* look backwards for beginning of a words (this random process
             tends to choose longer words) */
	  while ((offset >= 0) && (base[offset--] != '\n'));
	  ptr = &base[offset+2];

	  write(STDOUT_FILENO,ptr,strchr(ptr,'\n') - (int)ptr);
	  if (loops != 1) write(STDOUT_FILENO," ",1);
  }
  write(STDOUT_FILENO,".\n",2);
}