Button click counter on mail sent using php

Question

I am sending invitation mails using php mail(). I want to track how many people accept invitation and declined invitation. I am using two buttons for accept and decline. How can I implement click counter? Is it possible update count without redirecting page from mail to my website?

Answer 1

Create a file on your server: counter create a PHP file which increases or decreases the number in the counter file.

Increase:

$readf = fopen("counter", "r");             //open the file in read mode
$count = fread($readf,filesize("counter")); //read the content in it
fclose($readf);                             //close the file in read mode
$writef = fopen("counter", "w+");           //open the file in overwrite mode
$count++;                                   //increase the count by one
fwrite($writef, $count);                    //write changes to the file
fclose($writef);                            //close the file in overwriting mode

Decrease:

$readf = fopen("counter", "r");
$count = fread($readf,filesize("counter"));
fclose($readf);
$writef = fopen("counter", "w+");
$count--;
fwrite($writef, $count);
fclose($writef);

Make sure the file counter exists in the first place with the count 0:

if(!filesize("count")){
$writef = fopen("counter", "w+");
    fwrite($writef, "0");
    fclose($writef);
}