CSCI 330 Assignment 7 Automobile Database Shell Program

CSCI 330 Assignment 7 
Automobile Database Shell Program (100 pts)
Goal
Your task for this assignment is to write a shell script that will allow its user to create, view, and modify a simple
text-based database for automobiles. The script must be implemented with the Bourne shell syntax (use
bash). You may use any features available in the version of bash found on turing/hopper, as well as any Unix
command available there. Name your script file z1234567sh. Use your zid instead of z1234567, obviously.
Specification
Your script should support two ways of being run:
1 When run without any direct command-line options – your program is in interactive mode and should
prompt the user to find out what to do. Once you finish one task from the user, you should return to
that initial prompt and allow the user to request to do more, until they indicate that they would like to
quit. You have some leeway in how you accomplish this, but it must be possible to have it perform any
of the functions from below.
2 When run with direct command line options (as below) – do the task requested and exit immediately
when done.
# dbname - filename of database file to use
# command - which of the functions to call: "new", "insert", "display", "delete"
# param1 - first non-dbname parameter to whichever command function chosen
# ... - placeholder for parameters between 1 and N
# paramN - Nth parameter to whichever command function chosen
% ./z1234567sh dbname command param1 param2 ... paramN
Implementation
You must implement the following as bash functions:
▶ new() - This function is used to create a new database file. It takes up to two parameters:
1 The filename to use for the new database file. This must be specified.
2 The label to put on the first line of the new database file. If not specified, use "Untitled database"
instead.
▶ insert() - This function is used to add a record to an existing database file. It will always take five
parameters. If any of them are missing, it is an error.
1 The filename of the database to add the record to.
2 The make of the car to be stored in this new record. It is a string that must be longer than zero
characters.
3 The model of the car to be stored in this new record. It is a string that must be longer than zero
characters.
4 The year of the car to be stored in this new record. It must be a four-digit number, greater than
19 21 and smaller than 2029.
5 The color of the car to be stored in this new record. It is a string that must be longer than zero
characters.
CSCI 330 Assignment 7 (Spring 2021) 2 of 4
▶ display() - This function is used to show record(s) found in an existing database. This will take up to
four parameters, depending on the value of the second.
1 The filename of the database to show the record(s) from. Must be the filename of a readable file.
2 how many to show (one of all, single, or range)
▶ all - Show all of the records, example follows:
Automobile Database
Ford, Mustang, 2008, blue with white stripes
Mitsubishi, Lancer, 2009, white
Toyota, Camry LE, 2004, black
Porsche, Cayenne S, 2007, red
▶ single - Shows the single record in the position indicated by the third parameter. Notice that
record #1 is on the second line, after the label.
▶ range - Show the records in the range starting at the position indicated by the third parameter, up
to and including the record indicated by the fourth.
▶ delete() - This function is used to delete records from an existing database.
1 The filename of the database to delete record(s) from. Must be the filename of file readable and
writable by the current user..
2 how many to show (one of all, single, or range)
▶ all - Delete all of the records, but not the label for the database.
▶ single - Delete the single record in the position indicated by the third parameter. Notice that
record #1 is on the second line, after the label. It is an error to try to delete a record number that
does not exist.
▶ range - Delete the records in the range starting at the position indicated by the third parameter,
up to and including the record indicated by the fourth.
▶ count() - This function is used to count and print the number of rows in an existing database. It has
one parameter, which is not optional.
1 The filename of the database to count the records in, which must be readable by the current user.
Database Format
The format you must use for this database will be a text file, with a label for the database on the first line.
This label is what is written by the new() function. After the label, there is line per record that is added to the
database. The individual fields in the database records should be separated by commas. (“,”).
For example, the database file that produced the example for display() with all as its parameter would have
contained the following:
Automobile Database
Ford, Mustang, 2008, blue with white stripes
Mitsubishi, Lancer, 2009, white
Toyota, Camry LE, 2004, black
Porsche, Cayenne S, 2007, red
CSCI 330 Assignment 7 (Spring 2021) 3 of 4
Error Checking
If an error occurs, print an error message. If the script was run in interactive mode, return to the top of the
loop and allow them to try again. If it was used with directly specified command line arguments, it should
exit with a non-successful status code.
▶ Ensure that the command is spelled correctly.
▶ Ensure that all the required parameters to the appropriate command are present.
▶ Ensure that record numbers actually fit within lines present in the database file.
▶ Ensure that the database file exists and is readable (except for new(), where it shouldn’t exist) and, in
the case of insert() and delete(), also writable.
▶ If the file is empty (no records present), your script should print out a message that no records are
found.
Example runs
% ./z1234567sh DB new "Example for Assignment"
New database created
% ./z1234567sh DB insert Ford Mustang 2008 "blue with white stripes"
Successfully added a record to the database
% ./z1234567sh DB add Mitsubishi Lancer 2009 white
Successfully added a record to the database
% ./z1234567sh DB add Toyota "Camry LE" 2004 black
Successfully added a record to the database
% ./z1234567sh DB add Porsche "Cayenne S" 2007 red
Successfully added a record to the database
% ./z1234567sh DB display all
Example for Assignment
Ford, Mustang, 2008, blue with white stripes
Mitsubishi, Lancer, 2009, white
Toyota, Camry LE, 2004, black
Porsche, Cayenne S, 2007, red
% ./z1234567sh DB delete single 2
1 record deleted
% ./z1234567sh DB display all
Example for Assignment
Ford, Mustang, 2008, blue with white stripes
Toyota, Camry LE, 2004, black
Porsche, Cayenne S, 2007, red
% ./z1234567sh DB count
3
CSCI 330 Assignment 7 (Spring 2021) 4 of 4
% cat DB
Example for Assignment
Ford, Mustang, 2008, blue with white stripes
Toyota, Camry LE, 2004, black
Porsche, Cayenne S, 2007, red
Additional notes
▶ Be sure to test your script thoroughly.
▶ Your script file must use /bin/bash as the path in its shebang line.
▶ Make sure your script does not create any temporary files that are not removed before it ends.
▶ Make sure that your shell script is a regular Unix text file. (not a compiled program or C++ source code).
▶ This is to be done as a shell script. C++ is not acceptable for this assignment.
▶ All testing during grading will be done on turing and hopper. If the script you submit does not work
there, it is a you problem.
▶ Blackboard won’t allow files that end in .sh to be submitted, so make sure you call it z1234567sh (no file
extension) and not z1234567.sh.
What to turn in?
Turn in, via Blackboard, the script file you wrote. Make sure its name is as specified above.