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20130326a

Last N lines

During the Operating Systems lab you may have heard about the "tail" command. This command can print the last N lines of a text file. For instance, "tail -10 file.txt" prints the last 10 lines of the given file.

Exercise

Write a script that works similarly to the Unix "tail" command. How to use it:

./my_tail.py -10 input.txt

Version (B)

In order to practice OO programming, solve the exercise with a class. How to use it:

...
tail = Tail(<input_file>, <N>)
tail.print_result()

Where "print_result()" will print the last N lines of the the given input file.

Bonus point: if solved correctly, you can get +1 point.

I want to see a non-trivial solution! That is, I won't accept if you count the number of lines and then skip (number_of_lines - N) lines. I won't accept either if you read the whole content of the file to the memory. Find a different approach…

Tip: http://www.smartsmarina.com/product_photos/superior1.jpg, s/o/e/