Strings, regexp and files - php

Question

<?php
$iprange = array(
"^12\.34\.",
"^12\.35\.",
);
foreach($iprange as $var) {
if (preg_match($var, $_SERVER['REMOTE_ADDR'])) {
I'm looking to have a list that will constitute each of the values inside the array. Let's call it iprange.txt, from which I would extract the variable $iprange. I would also be updating the file with new ranges, but I also want to convert those strings to regexp if that's something that's needed in php, as it is in the above example.
If you could help me with the two following issues:
I understand that somehow I would be using an array include, but I'm not sure how to implement it.
I would like to run a cron that would update the text file and turn it into a regexp acceptable for use in the above example, if you think regexp is a good idea and there isn't another option. I know how to apply a cron in a directadmin gui, but I don't know what the cronned file would look like.
edit------------------------
Thanks Mamsaac, very helpful, right now I'm stuck on further issues that have risen that have to do with cases and ob_file_callback, and if I start talking about them here, I won't get anywhere, but they can be followed here: Problems with ob_file_callback and fwrite
As for this thread here, to keep it on topic, I wanted to ask you how would you go about including a whole file in the array you suggested?
I no longer need the cronjob you were thinking about if I don't have to convert strings to regular expression.

Answer 1

I will propose a different approach to the problem, if that's OK with you.
You could try using ip2long() function for this, making comparisons much faster. The advantage of doing it this way is that you can be very specific with each range (and in a natural way, where a range means "between two numbers".
So, you can do it something like this:
$ranges = array('10.20.8.0-10.20.14.254', '192.168.0.2-192.168.0.254');
foreach ($ranges as $iprange) {
list($lowerip, $highip) = explode('-', $iprange);
$remoteip = ip2long($_SERVER['REMOTE_ADDR']);
if (ip2long($lowerip) <= $remoteip && $remoteip <= ip2long($highip)) {
//it is within this range! I don't know what you want to do with it.
}
}
You could also use netmasks, but I will leave that as an exercise for you. To do it, you will play a bit with bitwise operations. Negate the mask, then use and bitwise and operation... Not what you requested! I might update this after I go to sleep.
About the file and cronjob. I am absolutely unsure of why you want a cronjob for this. How are you deciding what new ranges you will be accepting?
You can always read a file (you can use file_get_contents if you so desire and do a split on the string using
$ranges = explode("\n", file_get_contents("filename")) ;
and then you would have your array ready. (notice I even called it the same as in the block code above).
if the file ever gets REALLY big, avoid using the approach above and go ahead with fopen and fgets approach:
$file = #fopen("filename", "r"); //suppressing error messages, probably don't want that
if (!$file) {
//for some reason the file didn't open. Do error reporting or checking
}
$ranges = array();
while (($line = fgets($file)) !== false) {
$ranges[] = $line;
}
Seems like I'm only missing why you want to use a cronjob. Please elaborate on your criteria for deciding to add new IP ranges.

Answer 2

$ranges = array('12.34.1.0-12.34.14.254', '192.168.0.2-192.168.0.254');
foreach ($ranges as $iprange) {
list($lowerip, $highip) = explode('-', $iprange);
$remoteip = ip2long($_SERVER['REMOTE_ADDR']);
if (ip2long($lowerip) <= $remoteip && $remoteip <= ip2long($highip)) {
}
}
header("LOCATION: page1.php");
}
else
{
header("LOCATION: page2.php");
}
?>
I've isolated the if else and that works fine. I've also placed the two '}' at the end of your script both before and after my if else but no luck.