Compare IP with .txt file content

[wransik]

I'm trying to create a banlist based on a .txt file which has the IP's stored (one per line).

 

Now I'm comparing the current users IP with the .txt file content like this:

 

 

$file = file_get_contents( "text_file.txt" );
if( preg_match( "/$ip/", $file ) ) {
// block
}
 

My problem is that non-exact matches also trigger the block, for example 127.0.0.12 is in the .txt, my IP is 127.0.0.1 and I'm getting blocked.

 

How can I make it an exact match only ?

[Psycho]

Well, your preg match is looking for anything that contains "127.0.0.1", which is contained in "127.0.0.12". You could change the regex to look for values that match the value which begin and end with a "word boundary" (line break, space, tab, etc.)

 

if( preg_match( "#\b{$ip}\b#", $file )

 

Although you would be better off storing this in a database to make management easier.

Edited March 27, 2013 by Psycho

[litebearer]

Might also look into http://www.php.net/manual/en/function.file.php

inconjuction with http://php.net/manual/en/function.in-array.php

[wransik]

Thank you,

 

if( preg_match( "#\b{$ip}\b#", $file )
 

That did the trick.

[Psycho]

Might also look into http://www.php.net/manual/en/function.file.php

inconjuction with http://php.net/manual/en/function.in-array.php

 

I was thinking the same thing. Although RegEx is typically slower than string comparisons, in this case it's probably easier to execute a single RegEx against the entire file contents than creating ana array and looping through it. But, a database beats both of those ideas anyway.