Assignment 1: Bash Shell Scripting & Regular Expressions

Assignment 1: Bash Shell Scripting & Regular
Expressions

In this assignment, you will practice shell scripting and writing regular expressions. You may
work on this assignment with your peers (e.g., pair-programming), however, EACH student must
turn in their own assignment.
What To Do
Part 1: Bash Shell Scripts
You will write two scripts to manipulate data in a text file. Both of your scripts will produce the
same output, however, one script will use basic bash shell commands and the other will use the
UNIX command ‘awk’.
Step 1. Download the data file ‘studentGrades.txt’ from Canvas.
Step 2. Create a bash script file with the name ‘grades.sh’ and another bash script file with the
name ‘gradesAwk.sh’ that do the following:
a. Reads the contents of ‘studentGrades.txt’. You should read in the name of the data file
from the command-line arguments. The file names should not be hard coded in the
scripts! We will test the scripts with additional data files that have different records.
b. Calculates the average of the scores for each student record. Rounded or truncated
averages are accepted. Other data files that we will test your scripts with will also have
exactly 3 grades per record.
c. Sorts the output by average score in reverse order (i.e., high to low or descending
order), then by last name (i.e., ascending or default order), and then the first name (i.e.,
ascending or default order), then by ID (i.e., ascending or default order).
d. Formats the output as shown below:
99 [290010111] Lee, Terry
93 [928441032] Forester, Chris
92 [888111818] Forney, JC
91 [999999999] Smith, Jaime
82 [928441032] Forester, Jess
82 [123456789] Johnson, Lee
81 [199144454] Camp, Tracey
80 [434401929] Camp, Skyler
71 [299226663] Camp, Laney
**Note: The ID field is unique, however, student records may have the same scores, last
name, and first name. Your ‘grades.sh’ script may NOT use the UNIX ‘awk’ command.
Your ‘gradesAwk.sh’ script MUST use the UNIX ‘awk’ command.
Step 3. When your scripts are run without the text filename ‘studentGrade.txt’ as the
command-line argument, print out a usage statement. E.g.,
Usage: grades.sh filename
OR
Usage: gradesAwk.sh filename
Step 4. At the top of your scripts, include a comment with your name (and your partner’s name if
you pair-programmed with someone else).
Part 2: Regular Expressions
You will create a shell script with regular expressions that answer some questions about a data
file.
Step 1. Download the data file ‘regexData.txt’ from Canvas.
Step 2. Create a file named ‘regexAnswers.sh’. Write the regular expressions necessary to
answer the questions below in ‘regexAnswers.sh’. Write one regular expression per line. If you
do not know the answer to a question, use ‘echo “0”’ so that your answers align with the
questions (i.e. the regular expression for question 4 should be the 4th regular expression in the
file).
Questions
1. How many lines end with a number or an alphabetic letter?
2. How many lines do not start with a vowel?
3. How many lines have 12 or more alphabetic letters?
4. How many lines contain only numbers? (e.g., 4, 32, 94932, etc.)
5. How many email addresses are from UCDenver? (e.g., end with ‘UCDenver.edu’)
6. How many phone numbers are in the data file (i.e., format: _ _ _ - _ _ _ - _ _ _ _ ) ?
7. How many city of Boulder phone numbers are in the data file? (e.g., starting with 303
- _ _ _ - _ _ _ _ ) ?
8. How many lines begin with a vowel and end with a number?
9. How many email addresses are in ‘first.last’ name format and involve someone
whose first name starts with a letter in the second half of the alphabet? (e.g., first
half: A - M or a - m, second half: O - Z or o - z)
Step 3. When your scripts are run without the text filename ‘studentGrade.txt’ as the
command-line argument, print out a usage statement. E.g.,
Usage: regexAnswers.sh filename
Step 4. At the top of your scripts, include a comment with your name (and your partner’s name if
you pair-programmed with someone else).
**Hints: The commands grep and egrep treat braces (i.e., { }) differently. Make sure you
check for word boundaries (e.g., ‘\b’) where appropriate.
What To Turn In
You will submit a single ZIP file containing all three scripts and upload it to Canvas. EACH
student must submit their own ZIP file.