I got a weird Problem here, need your help. PHP Language.

Suppose I have a Output like this:

> 
> A  
> 
>  B  
> 
>  C  
> 
>  D  
> 
>  E
> 
> 
> 

Now Instead of 5 Lines, I want out in 2 Lines and 3rd line will be "more" which will take him to another page for details(I know how to place anchor tag :S)

And if The ouput is like

> 
> This is a big paragraph of 5 lines or maybe more, but what I want to display is only first 100(or some first n Characters). Repeated This is a big paragraph of 5 lines or maybe more, but what I want to display is only first 100(or some first n Characters)This is a big paragraph of 5 lines or maybe more, but what I want to display is only first 100(or some first n Characters)This is a big paragraph of 5 lines or maybe more, but what I want to display is only first 100(or some first n Characters)This is a big paragraph of 5 lines or maybe more, but what I want to display is only first 100(or some first n Characters).
> 
> 
> 

Instead of this I want to display only first 100 characters and then a more button which will take to a detailed page. 

The Second Problem can be solved with php function substr, but what about the first one ? I need both cases to work at same place, like if input has some list(hell of newline characters) at starting then only top 2 lines will be printed And if it is a paragraph then only first 100(or some n) characters(or even words) will be printed.  

Any Guesses ?