CS2043 Assignment 2 Solution

CS2043 Assignment 2

Note: This assignment (and future ones) require you to have access to a Unix-like (Linux,
Mac OS X, etc) machine. If you do not have such an operating system installed on your local
machine, make sure to get a CSUGLab account (by contacting the course staff). Different
systems have slightly different configurations. The main environment in this class will be
GNU/Linux.
You must complete this assignment using only the Unix tools that were discussed in class
between the first lecture and Lecture 7. That means that you are not allowed to use loops
either in bash or in any other programming language.
For each problem, you will write a script (not the output thereof), and save it to a file named
with the specified problem label, e.g., problem1name.sh. Assume that the input is in the
same directory as the script. Remember that a bash script is a text file with: #! /bin/bash
as the first line.
Start this assignment early. It is somewhat longer and more challenging than the previous
one!
Tweets
1. Copy the file:
http://www.cs.cornell.edu/courses/cs2043/2015sp/assignments/tweets.tar.gz
and extract it into your home folder. This is a compressed tarball of a folder with 2000
text tweets.
2. Write a script wordfreq.sh to compute the number of words per tweet and output:
(a) in a file called min_words.txt the minimum # of words in any tweet
(b) in a file called max_words.txt the maximum # of words in any tweet
(c) in a file called avg_words.txt the average # of words per tweet
Round the average down to the nearest integer.
1
CS2043 Assignment 2 January 31, 2015
3. Write a script charfreq.sh to compute the number of characters per tweet and output:
(a) in a file called min_chars.txt the minimum # of chars. in any tweet
(b) in a file called max_chars.txt the maximum # of chars. in any tweet
(c) in a file called avg_chars.txt the average # of chars. in any tweet
Round the average down to the nearest integer.
4. Write a script commword.sh to compute the most common words among all tweets
and output in a file called most_common.txt the top 10 most common words sorted by
popularity (with the most common first i.e. descending order)
Note that the contents of your output files from the above scripts should only be numbers.
Reading Frankenstein
1. Download the plain text version of the book Frankenstein from:
http://www.cs.cornell.edu/courses/cs2043/2015sp/assignments/frankenstein.txt
2. Write a script called frankenread.sh to extract the 10 most used words in Letter 3 of
the Frankenstein text. Words should contain no punctuation marks and the different
forms of words with capital and lower case letters should be considered the same word,
e.g., ”The” and ”the” are the same words, and ”tree!” and ”man,” are not words, but
the trimmed version ”tree” and ”man” are.
Hint: Letter 3 is between lines 255 and 298 of the file frankenstein.txt.
Write a short feedback document, README.txt, regarding this assignment and include it
in your submission folder:
1. How did you find the assignment? Was it easy/hard? boring/interesting?
2. Is there something general or specific you would like to see covered later in the course?
3. Any other questions or concerns you may have
Once you are done, create a compressed tarball (compressed using bzip2) of the folder containing your answers and submit your tar archive using CMS. Please include all the scripts
and output files that you used to complete all of the above tasks. Remember that your best
friends, if you get stuck, are the man tool, piazza and your favorite search engine.
2