Regarding the `line` script, just a note that sed can print an arbitrary line from a file, no need to invoke a pipeline of cat, head, and tail:

    sed -n 2p file

prints the second line of file. The advantage sed has over this line script is it can also print more than one line, should you need to:

    sed -n 2,4p file

prints lines 2 through 4, inclusive.