I use the following with no problems

$bob = "a string";

printf("%-15s",$bob);

to print the following (padded to 15 characters):

"a string_ _ _ _ _ _ _"

However, I'm having trouble locating the attribute that would truncate the string. I have a field that I simply want to print on a page that is *limited* to x number of characters and was trying to use printf.

Example:

$bob = "a really long string and I only want part of it";

would return:

"a really long stri";