From the terminal (SSH):
grep -Ril "find /home/username/public_html/ -type f -mtime -2"
From a .php file:
<?php
$last=shell_exec('grep -Ril "find /home/username/public_html/ -type f -mtime -2"');
echo "<pre>$last</pre>";
?>
The output will be just a file name:
If you see a blank page after opening the php file in your browser, contact your hosting provider and ask theem to enable shell_exec