Looking for a string function

Greetigns Gents, I seem to remember a built in php function that will take a huge block of text. Then just spit out X number of characters from it and follow it with an additional string value. But I cannot remember what it is. I seem to remember it being something other than the substr(). I am looking to pull the first say 200 characters from an article and follow the last character/word with something like ... Does anyone know what I am talking about, or am I just smoking something and my memory is going? Blessed Be Phillip