session_abort() closes the current session and discards the changes applied to Session array in the current page , it doesn't delete the session file
let me explain with one example.
page 1.php :
<?php
session_start();
$_SESSION['city']="Sydney";
echo "<a href=\"2.php\"> page2</a>";
?>
when you open this page , a session file is created on the server (to find out where session files are saved run "echo session_save_path()" ) with the name of session_id and the content of the variable :
sess_o22iabs75j93uhc7i4jf1lecjk (file name)
city|s:6:"Sydney"; (content)
if we go to 2.php containing this code :
<?php
session_start();
$_SESSION['country']="Australia";
echo session_encode();
session_abort();
session_start();
echo "<br>".session_encode();
?>
when session_abort is executed , the session is closed and the change which here is the 'country' element of Session array is discarded .
Output :
city|s:6:"Sydney";country|s:9:"Australia";
city|s:6:"Sydney";
