You could use PHP’s file system to write a simple text file that can serve as a mini database.
In PHP you can read text files using file($name_of_file); which returns an array for you.
So if the file contained IP addressed.
Let’s say example.txt contains these three lines:
12.10.100
12.11.200
12.12.300
If you do print_r( file( 'example.txt' ) );
You’ll get an array of:
Array(
[0] => 12.10.100
[1] => 12.11.200
[2] => 12.12.300
)
Then before the form loads, you can check if IP is present in the array and handle it appropriately. If not, then write functionality that once the user submits form, add their IP to the file.
To check for value you could use PHP’s in_array(); function.
Hope that helps.
