Database Management System (Bourne Shell)

Database Management System (Bourne Shell) To build a database management system for a hospital. The database maintains a collection of patient records and the risk factor for stroke due to hypertension.  Overview The purpose of this project is to display skills in programming Bourne shell script using some fundamental concepts, including variable assignment and access, […]
Project Name
Database Management System (Bourne Shell)
Project Goal
To build a database management system for a hospital. The database maintains a collection of patient records and the risk factor for stroke due to hypertension.

Details

 Overview

The purpose of this project is to display skills in programming Bourne shell script using some fundamental concepts, including variable assignment and access, variable reading, positional variables, branches and loops, and simple arithmetic. Advanced Unix utilities such as awk, sed, tr will also be used.

In terms of interface and functionality this project is similar as the Database Management System that was original written on the C language but re-written on Bourne Shell.

Compared against C language, shell programming language usually does simpler things. There are no data structures maintained here using shell script. Instead, the database is maintained by writing to and reading from a regular text file directly.

The text file maintains a collection of patient records and the risk factor for stroke due to hypertension.

The program will provide several basic functions:

  • Entry of a new patient record into the current database
  • Display of all patient record in the current database
  • Modification of an existing patient record in the current database
  • Sorting the patient records in the current database
  • Saving current database to disk
  • Loading a database from disk
  • Clearing the current database
  • Emptying the disk file.


Documentation

Each patient record contains the following information fields:

  • name, which represents the patient’s name
  • age, which represents the patient’s age
  • highBP, which represents the patient’s high (systolic) blood pressure
  • lowBP, which represents the patient’s low (diastolic) blood pressure
  • riskFactor, which represents the patient’s risk factor for stroke due to hypertension.

Upon entering a new patient into the database, the program reads in patient’s name, age, high blood pressure and low blood pressure. It then calculates and sets the risk factor of the new patient. The program then creates a new patient record and inserts the new record into the database. 

Assume a high blood pressure is higher than a low blood pressure. Assume the optimal high blood pressure (optimalH) is 120 and optimal low blood pressure (optimalL) is 80. The risk factor is evaluated as follows:

  • The risk factor is 0 if both the blood pressures are below (or equal to) their optimal value. That is, the high blood pressure is not higher than optimalH and low blood pressure is not higher than optimalL.
  • If one of blood pressure is below (or equal to) to its optimal value, but the other is above the optimal value by no more than 10, then the risk factor is 1.
  • If both the pressures are above their optimal value (but) by no more than 10, then the risk factor is 2.
  • If one pressure is below (or equal to) its optimal value, but the other is above the optimal value by 11-20, then the risk factor is 3.
  • If both the pressures are higher than the their optimal value by 11-20, then the risk factor is 4.
  • In all other cases, the risk factor is 5.

The above evaluation criterion applies to patients who are no more than 50 years of age. If the patient is more than 50 years of age, then each case above has additional risk factor of 0.5, except the first case where both the blood pressure are below (or equal to) their optimal values.


Development

 References

  1. Mastering Unix Shell Scripting, 2nd Edition
    Randal K. Michael
  2. Unix & Linux Visual QuickStart Guide, 5th Edition
    Deborah S. Ray and Eric J. Ray
  3. Pro Bash Programming
    Chris F. A. Johnson
  4. Unix and Linux System Administration and Shell Programming
    Milo