dlst
12-26-2001, 10:00 PM
Hi all.
I have a client that runs a board that has about 100 members that are his personal friends, and the other 3400 members are just regular users. Lately poeple have been registering with usernames very similar to those of his friends, and his friends are complaining.
He asked me for a way to display a list of usernames that "sound like" or "are similar to" existing users, so that when he moderates user registrations it's easy to make a decision as to allow the new user or not.
Anyway, this VERY simple hack searches the database for existing usernames, and checks to see if they are similar to the username that is being registered. If it finds any, it simply lists them.
The system uses my own combination of metaphone and levenshtein to try to find similar matches.
There are options in the code to limit the number of returned matches, and to set the "tolerance level" of the search. A higher tolerance allows more matches.
Did I mention this was an EXCEEDINGLY simple hack? The only modifications are to admin/user.php.
You need to add two bits of code. The first is around line 1182, when you see the following code:
$users=$DB_site->query("SELECT userid,username,email FROM user WHERE usergroupid=4 ORDER BY username");
Add this AFTER the code above:
// DLST hack! Show similar usernames when moderating a user signup
// to speed things up, get an array of all the users in the system here
$sim_all_users=$DB_site->query("SELECT username FROM user WHERE usergroupid!=4");
while ($sim_all_user=$DB_site->fetch_array($sim_all_users)) {
$sim_arr_all_users[] = $sim_all_user[username];
}
// now we have $sim_arr_all_users, an array with all the usernames in the system that a current
// END
Then, find the following (a couple lines down, around 1190):
echo "<td><p>$user[username]</p></td><td><p><a href=\"mailto:$user['email']\">$user['email']</a></p></td><td><p><a href=\"user.php?s=$session[sessionhash]&action=edit&userid=$user[userid]\" target=_blank>View profile</a></p></td></tr>\n";
And add this code AFTER:
// DLST hack! Show similar usernames when moderating a user signup
//********************
// Options for Show Similar Usernames Hack
$sim_limit_show = 10; // maximum number of similar names to show
$sim_tolerance = 2; // how close a match to the username do you want? The lower it is, the closer
// the usernames must match to show up in list. Experiment for yourself, but
// this number works best for me.
// END Options
//********************
// $user[username] is the username trying to get registered
// $sim_message is the list of similar usernames that gets generated
$sim_meta1 = metaphone( $user[username] ); // get the metaphone for the username we are checking
reset ($sim_arr_all_users); // reset the array
while ( $sim_thiscount < $sim_limit_show && list(, $sim_current_user) = each ($sim_arr_all_users) ) {
$sim_meta2 = metaphone( $sim_current_user ); // get the metaphone for the usernames that already exist
$sim_score = levenshtein( $sim_meta1, $sim_meta2 ); // generate a score with the lev. method
if ( $sim_score <= $sim_tolerance ) { // compare the score to the tolerance (set above)
$sim_users_found[] = $sim_current_user; // if it's good, add it to the list
$sim_thiscount++; // increase the count of matched usernames by one
}
}
if ( $sim_thiscount > 0 ) {
$sim_message = "A total of $sim_thiscount similar users were found: ";
foreach ($sim_users_found as $sim_value) {
$sim_message .= "<b>$sim_value</b>, ";
}
$sim_message = substr( $sim_message, 0, -2 ); // remove the last comma
} else {
$sim_message = "No similar usernames were found in the user list.";
}
//echo "<tr><td><p>Validate option</p></td><td><p>$user[username]</p></td><td><p>$user["email"]</p></td><td><p>View profile</p></td></tr>\n";
echo "<tr class='".getrowbg()."'><td><p></p></td><td colspan=3><p>$sim_message</p></td></tr>\n";
unset($sim_meta1, $sim_thiscount);
// END DLST hack
And that's it! Moderate a user registration to see it in action.
I'd very much like to get as much feedback as possible for this, so don't hold back! If you have any suggestions, or ways to optimize the code further, also let me know.
-DLST
I have a client that runs a board that has about 100 members that are his personal friends, and the other 3400 members are just regular users. Lately poeple have been registering with usernames very similar to those of his friends, and his friends are complaining.
He asked me for a way to display a list of usernames that "sound like" or "are similar to" existing users, so that when he moderates user registrations it's easy to make a decision as to allow the new user or not.
Anyway, this VERY simple hack searches the database for existing usernames, and checks to see if they are similar to the username that is being registered. If it finds any, it simply lists them.
The system uses my own combination of metaphone and levenshtein to try to find similar matches.
There are options in the code to limit the number of returned matches, and to set the "tolerance level" of the search. A higher tolerance allows more matches.
Did I mention this was an EXCEEDINGLY simple hack? The only modifications are to admin/user.php.
You need to add two bits of code. The first is around line 1182, when you see the following code:
$users=$DB_site->query("SELECT userid,username,email FROM user WHERE usergroupid=4 ORDER BY username");
Add this AFTER the code above:
// DLST hack! Show similar usernames when moderating a user signup
// to speed things up, get an array of all the users in the system here
$sim_all_users=$DB_site->query("SELECT username FROM user WHERE usergroupid!=4");
while ($sim_all_user=$DB_site->fetch_array($sim_all_users)) {
$sim_arr_all_users[] = $sim_all_user[username];
}
// now we have $sim_arr_all_users, an array with all the usernames in the system that a current
// END
Then, find the following (a couple lines down, around 1190):
echo "<td><p>$user[username]</p></td><td><p><a href=\"mailto:$user['email']\">$user['email']</a></p></td><td><p><a href=\"user.php?s=$session[sessionhash]&action=edit&userid=$user[userid]\" target=_blank>View profile</a></p></td></tr>\n";
And add this code AFTER:
// DLST hack! Show similar usernames when moderating a user signup
//********************
// Options for Show Similar Usernames Hack
$sim_limit_show = 10; // maximum number of similar names to show
$sim_tolerance = 2; // how close a match to the username do you want? The lower it is, the closer
// the usernames must match to show up in list. Experiment for yourself, but
// this number works best for me.
// END Options
//********************
// $user[username] is the username trying to get registered
// $sim_message is the list of similar usernames that gets generated
$sim_meta1 = metaphone( $user[username] ); // get the metaphone for the username we are checking
reset ($sim_arr_all_users); // reset the array
while ( $sim_thiscount < $sim_limit_show && list(, $sim_current_user) = each ($sim_arr_all_users) ) {
$sim_meta2 = metaphone( $sim_current_user ); // get the metaphone for the usernames that already exist
$sim_score = levenshtein( $sim_meta1, $sim_meta2 ); // generate a score with the lev. method
if ( $sim_score <= $sim_tolerance ) { // compare the score to the tolerance (set above)
$sim_users_found[] = $sim_current_user; // if it's good, add it to the list
$sim_thiscount++; // increase the count of matched usernames by one
}
}
if ( $sim_thiscount > 0 ) {
$sim_message = "A total of $sim_thiscount similar users were found: ";
foreach ($sim_users_found as $sim_value) {
$sim_message .= "<b>$sim_value</b>, ";
}
$sim_message = substr( $sim_message, 0, -2 ); // remove the last comma
} else {
$sim_message = "No similar usernames were found in the user list.";
}
//echo "<tr><td><p>Validate option</p></td><td><p>$user[username]</p></td><td><p>$user["email"]</p></td><td><p>View profile</p></td></tr>\n";
echo "<tr class='".getrowbg()."'><td><p></p></td><td colspan=3><p>$sim_message</p></td></tr>\n";
unset($sim_meta1, $sim_thiscount);
// END DLST hack
And that's it! Moderate a user registration to see it in action.
I'd very much like to get as much feedback as possible for this, so don't hold back! If you have any suggestions, or ways to optimize the code further, also let me know.
-DLST