You are given a large text fi le. Which program would you use to select: a) duplicate lines, b) unique lines, c) lines containing a specifi c pattern, d) lines beginning with a specifi c pattern, e)...

You are given a large text fi le. Which program would you use to select: a) duplicate lines, b) unique lines, c) lines containing a specifi c pattern, d) lines beginning with a specifi c pattern, e) columns of data?

The fold, fmt and pr programs can all be used to reformat text. What are principal differences between these programs?