Perl string uc() function - Quick Tutorial

 $STRING = uc($STRING); 

Perl's uc() function takes a string, makes the entire thing uppercase, and then returns the new string.

 $myWord = 'word';
 $myUpperWord = uc($myWord); 

First, $myWord is set to a value of 'word', then the uc() function is run on $myWord. The uc() function takes the entire string $myWord and converts it to it's uppercase equivalent. The value of $myUpperWord is then equal to 'WORD'.