PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

594 Chapter 27 Building User Authentication and Personalization
Listing 27.19
Continued
}
$word = fgets($fp, 80); // skip first word as it could be partial
$word = fgets($fp, 80); // the potential password
}
$word = trim($word); // trim the trailing \n from fgets
return $word;
}
To work, the get_random_word() function needs a dictionary. If you are using a Unix
system, the built-in spell checker ispell comes with a dictionary of words, typically located
at /usr/dict/words, as it is here, or at /usr/share/dict/words. If you don’t find it
in one of these places, on most systems you can find yours by typing
$ locate dict/words
If you are using some other system or do not want to install ispell, don’t worry! You can
download word lists as used by ispell from http://wordlist.sourceforge.net/.
This site also has dictionaries in many other languages, so if you would like a random,
say, Norwegian or Esperanto word, you can download one of those dictionaries instead.
These files are formatted with each word on a separate line, separated by newlines.
To get a random word from this file, you pick a random location between 0 and the
filesize, and read from the file there. If you read from the random location to the next
newline, you will most likely get only a partial word, so you skip the line you open the
file to and take the next word as your word by calling fgets() twice.
The function has two clever bits.The first is that, if you reach the end of the file
while looking for a word, you go back to the beginning:
if (feof($fp)) {
fseek($fp, 0);
}
// if at end, go to start
The second is that you can seek for a word of a particular length:You check each word
that you pull from the dictionary, and, if it is not between $min_length and
$max_length, you keep searching. At the same time, you also dump words with apostrophes
(single quotation marks) in them.You could escape them out when using the word,
but just getting the next word is easier.
Back in reset_password(), after you have generated a new password, you update the
database to reflect this and return the new password to the main script.This is then
passed on to notify_password(), which emails it to the user.The notify_password()
function is shown in Listing 27.20.