How do I truncate or remove a trailing character

[Bret Goodfellow]

Okay, I know this has to be simple, but because I am trying to truncate
or remove a special character I've run into a roadblock.  Here's what I
want to do.  
 
$value = "12345)" ;
 
How do I change $value so that the trailing ")" is removed.  In
otherwords with the given example, how do I manipulate $value so that
its value is "12345"?  Please keep in mind that $value may be variable
in length, so I can't use substr($value, 0, 5).  Can split be used to do
this?  Stumped.