Hello everyone!
Today I'll try and teach you how to use files to count logged in users!
I've tried to make this script partly editable, so please change the options as you wish!

<?php function online() { // CONFIG $config["log_file"] = "online.txt"; // File's name Change this) $config["min_online"] = 1; // Min online time // END CONFIG

First of all, YES this IS a function, so please be nice to it ;-) I'll try to join all parts so you can copy and paste all this code straight from the box and put it together!

Feel free to edit the $config array values, try not to change the name if you can ;-)

Next, we check if the file exists, thanks to Specific for this idea :)

// Is it even there? if not, lets make it ;-) Thanks Specific! $config["log_file"] = $_SERVER['DOCUMENT_ROOT']."/".$config["log_file"]; if(!file_exists($config["log_file"])) { $user_f_create = fopen($config["log_file"], "w") or die("Cannot create file, you must manually create it. Please create a file called " . $config["log_file"]); fwrite($user_f_create, ""); fclose($user_f_create); }

Of course, this would die if the file could not be created, (You probably don't have permissions to create please fix ;-)

Alright, now, lets get the IP address!

if ($HTTP_X_FORWARDED_FOR == "") { $ip = getenv(REMOTE_ADDR); } else { $ip = getenv(HTTP_X_FORWARDED_FOR); }

There are many ways you can do this, also, if you're worried about somebody opening up the file and reading users IP's, feel free to MD5 the getenv values just for a bit of extra security :)

Now lets get the date and time they connected!

// Get dates and times $date = explode(":", date("d:m:Y")); $date_out = "$date[0]-$date[1]-$date[2]"; $time = explode(":", date("H:i:s")); $time_out = "$time[0]:$time[1]:$time[2]";

You should leave this part alone, the script is pretty sensitive about this stuff!

Next. We're going to open up the previous log file, and get all the users in it!

But we gotta make sure its there first!

// Bit o' error checking no file, cant open it right? if(@filesize($config["log_file"]) > 0) { // Open the file and read $users_read_f = fopen($config["log_file"], "r"); $users = fread($users_read_f, filesize($config["log_file"])); fclose($users_read_f); } else { $users = ""; } $to_write = "$ip|$time_out|$date_out";

Yes $users will be set to blank if the file is empty!

Now, we add an IF to see what $users is, if it IS empty then we're the first online!

if($users == "") { // Nobody online? :( $user_write = fopen($config["log_file"], "w"); fputs($user_write, $to_write); fclose($user_write);

Of course, with every IF, we need an ELSE! (or atleast in this case!

} else { // Hey hey! Someone's online $users = explode("\n", $users); $online_users = array(); while (list($key, $val) = each($users)) { $user_info = explode("|", $val); $t = explode(":", $user_info[1]); if($date_out == $user_info[2]) { if($ip != $user_info[0]) { // Not our user? lets see if the other's are still on? if(($t[0] == $time[0]) && (($time[1] - $t[1]) <= $config["min_online"])) { $online_users[] = $val; } if(($t[0] == ($time[0] - 1)) && ((($time[1] + 2) - $t[1]) <= $config["min_online"])) { $online_users[] = $val; } } } }

Alright! Someone else is online (or my other self), now, lets get their info from the file!

First we better check if it's been updated since before today, if not, we dont want them back in our file!

Also, we want to make sure its not US that we're looking at!

Next we check if the they were online Less then the value in $config["min_online"] if its MORE, we'll say they've stopped viewing! if so, we'll add them BACK into the file with their orignal time!

$online_users[] = $to_write; // Lets put it all back now shall we? First empty the file! $user_write = fopen($config["log_file"], "w"); fputs($user_write , ""); fclose($user_write ); while (list($k, $v) = each($online_users)) { $new_file_log = fopen($config["log_file"], "a"); fwrite($new_file_log, "$v\n"); fclose($new_file_log); } }

Alright, now we add our information to $online_users since we're online! right? :)

Next, we empty the old file, now that we have everyting we need!

The next wile is to insert all the data back into the log file :) including our connection time!

if(@filesize($config["log_file"]) > 0) { $users_online_read = fopen($config["log_file"], "r"); $users_online = fread($users_online_read, filesize($config["log_file"])); fclose($users_online_read); $users_online = explode("\n", $users_online); $n_u_online = count($users_online)-1; if($n_u_online == 0) { $n_u_online = 1; } } else { $n_u_online = 1; } return "$n_u_online"; }

Now, we finish everything off!

The if is to check that the file DOES have information in it, it was orignally used because the first script run returned 0 online users, this makes sure it returns atleast 1!

Then we count the number of entries in the file, (minusing 1 for the extra \n at the end of the file!)

However, if there is only 1 line, then we'll be back at 0! so we'll add a check for that and make it 1 if thats the problem,

Then we return the number of users online!

// Users online! print "Users online: " . online();

The above is just a simple useage of this script. I hope you all learnt something here!

Enjoy showing your users how many people are online! (The fast way!)