1  ./pretty --width=64 --centered --newline gettysburg.txt 
2  ./pretty -w=64 -c -n gettysburg.txt 
3  ./pretty -w 64 -c -n gettysburg.txt 
4  cat gettysburg.txt | ./pretty --width=64 --centered --newline 


1  Four score and seven years ago our fathers brought forth on this 
2  continent, a new nation, conceived in Liberty, and dedicated to 
3          the proposition that all men are created equal. 
4   
5   Now we are engaged in a great civil war, testing whether that 
6   nation, or any nation so conceived and so dedicated, can long 
7  endure. We are met on a great battle-field of that war. We have 
8    come to dedicate a portion of that field, as a final resting 
9  place for those who here gave their lives that that nation might 
10    live. It is altogether fitting and proper that we should do 
11                               this. 

Example 4: Centered output.