Help with php function

[ggrant3]

I would like to have a function that takes the customers email address from a certain field, check to make sure the email does not already exist, and if it does not then store the email address into a file.

 

But I am still new to php and I am not sure if what I have so far is correct or even what else needs to be added.

 

Also where in the script should I place this code (it is part of a form)?

 

<?php
// Define filename and open in read-write append mode
     $filename = 'C:/private/customeremail.txt';
     $file = fopen($filename, 'a+');
     // If filesize is zero, no names yet registered
     // So just write the customer email to file
     if (filesize($filename) === 0) {
       fwrite($file, "$email");
       }
      // If filesize is greater than zero, check customer email first
      else {
         // Move the internal pointer to the beginning of file
         rewind($file);
         // Loop through file one line at a time while (!feof($file)) {
             $line = fgets($file);
             // Split line at comma, and check first element against customer email
             $tmp = explode(', ', $line);
  
// close the file
fclose($file);
}
}

 

 

 

That is all I have been able to come up with so far.