<?php
$string = "AS A SINGLE FOOTSTEP WILL NOT MAKE A PATH ON THE EARTH, SO A SINGLE THOUGHT WILL NOT MAKE A PATHWAY IN THE MIND. TO MAKE A DEEP PHYSICAL PATH, WE WALK AGAIN AND AGAIN. TO MAKE A DEEP MENTAL PATH, WE MUST THINK OVER AND OVER, THE KIND OF THOUGHTS WE WISH TO DOMINATE OUR LIVES.";
echo str_to_lower($string);
Fatal error: Uncaught Error: Call to undefined function str_to_lower() in /in/B5UOX:5
Stack trace:
#0 {main}
thrown in /in/B5UOX on line 5
Process exited with code 255.