Homework 1 Extracting Data from a CSV file Solution

Description

This assignment is based on a class of problem solved in enterprise computing; extraction, transfor-mation, and loading. This is often referred to as ETL. The inputs will be data extracted from a leading aviation industry data and consulting firm, GCR. (See GCR.com for additional data.) The data is in a well known format where each data element is separated from the previous and following data elements by using a comma. It should be noted that this method of data manipulation is extremely common. The explicit order of the data fields and the desired outputs are defined in the “Specifications”.

• Objectives

The objectives of this assignment are to demonstrate proficiency in file I/O, data structures, and data trans-formation using C language resources. Specifically, you will read in data from a text file, use that data to populate a data structure, and print that data to STDOUT by accessing the newly populated structure.

1.1 Extraction

The first part of ETL is extraction. The filename of a text file will be passed to your program via the com-mand line. The data contained in that file is to be read into memory (i.e., extracted). Your program will be compiled and run on Eustis using the following commands:

gcc -o etl hw1etl.c

./etl inputFile

It is entirely possible that the input file either does not exist or is not where it is supposed to be. In such an event, your program should print an error message to STDERR that indicates which file is missing, then your program should exit safely. Use the following format for your error message (fileName should display the actual name of the missing file):

etl ERROR: File “fileName” not found.

The input file is in CSV (comma separated values) format where each line contains the data for one airport and the fields are as printed below. Note that these fields vary in size and content. Some fields may even be empty. Also note that the data for some of the fields are a melange of types. Specifically, the FAA Site Number and both latitude and longitude contain numbers, punctuation, and text.

For this assignment, treat all input data as character data.

Table 1: Airports Data Fields

Field Title	Description	Size
FAA Site Number	Contains leading digits followed	Leading digits followed by a
	by a decimal point and short text	decimal point and zero to two
		digits and a letter
Loc ID	The airport’s short name, i.e.	4 characters
	MCO for Orlando
Airport Name	The airport’s full name, i.e. Or-	50 characters
	lando International
Associated City	The nearest city	50 characters
State	State	2 characters
Region	FAA Region	3 characters
ADO	Airline Dispatch Office	3 characters
Use	Public or Private	2 characters
Latitude	DD-MM-ss.ssssDirection	Degrees, minutes, seconds. Di-
		rection is either N,S,E or W.
		Treated as a string (for now).
Longitude	See Latitude above.	ditto
Airport Ownership	Public or Private	2 characters
Part 139	FAA Regulation	No data
NPIAS Service Level	National Plan Integrated Airport	50 characters
	Systems Descriptor
NPIAS Hub Type	Intentionally left blank	n/a
Airport Control Tower	Y/N	one character
Fuel	Fuel types available	up to 6 characters
Other Services	Collections of tag indicating IN-	12 characters
	STRuction, etc.
Based Aircraft Total	Number of aircraft (may be	Integer number
	blank)
Total Operations	Takeoffs/Landings/etc (may be	Integer number
	blank)

1.2 Transformation

The second part of ETL is transformation. A list of comma separated values is convenient for text files, but it is far less convenient in memory. Once the data for a single airport has been read into a buffer, you will need to parse the buffer based on the commas between the data fields. The parsed data will then be used to populate a structure of the type struct airPdata (i.e. the data has been transformed from CSV to a data structure). The format of airPdata, shown below, will be defined in airPdata.h. Note that the airPdata structure uses the same names as the input file’s Field Names (See Table 1 on page 2), though not all of the Field Names are used.

typedef struct airPdata{

char _*siteNumber; //FAA Site Number

char *LocID;		//Airport’s	‘‘Short Name’’, \textit{e.g.} MCO
char *fieldName; //Airport			Name
char	*city;	//Associated City
char	*state;	//State

char _*latitude; //Latitude

char _*longitude; //Longitude

char controlTower;//Control Tower, this is a single character (Y/N) } airPdata;

Remember, some of these fields will be of differing lengths for each airport. When you allocate memory structure’s fields, you can assume that no entry will be longer than 50 characters (plus 1 character for the terminating NULL).

1.3 Loading

Finally, the third part of ETL is loading. With the data now in an airPdata structure it can be eas-ily accessed by functions and/or other programs (i.e., loaded). For this assignment, you will use pass the airPdata structure to a function ( PrintData(airPdata airport) ) that will print the data to STDOUT (aka the console). Before calling PrintData for the first time, make sure you print a header line that names each column. Specifically, use the following two lines of code:

printf(“%-12s %-11s %-42s %-34s %-3s %-15s %-16s Towernn”, “FAA Site”, “Short Name”, “Airport Name”, “City”, “ST”, “Latitude”, “Longitude”);

printf(“%-12s %-11s %-42s %-34s %-3s %-15s %-16s =====nn”, “========”, “==========”, “============”, “====”, “==”, “========”, “=========”);

The “-” preceding each of the format specifiers left-justifies the printed values, while the numbers in-dicate the width of the printed field. Your data should be left-justified as well and should use widths that are identical to those in the header line. It is your choice whether you want to populate one airPdata structure and then print it, or to populate an array of airPdata structures and then print each of them. If you choose to populate and print one at a time, be sure to free any allocated memory before reallocating for the same variable. If you choose to read in all of the airports before printing them, you will have an easier time modifying your HW1 code when it comes time for HW3 and will only need to free the memory when you are done. Again, the choice is yours. An example of what the output should look like is shown on the next page.

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FAA Site	Short Name	Airport Name	City	ST	Latitude	Longitude	Tower
========	==========	============	====	==	========	=========	=====
03406.20*H 2FD7		AIR ORLANDO	ORLANDO	FL	28-26-08.0210N	081-28-23.2590W	N
03406.31*H 3FD5		ARNOLD PALMER HOSPITAL	ORLANDO	FL	28-31-21.0090N	081-22-49.2520W	N
03406.36*H 2FL5		BROOKSVILLE INTL AIRWAYS- INC	ORLANDO	FL	28-25-26.0000N	081-27-35.0000W	N
03406.24*H FD99		DR P PHILLIPS HOSPITAL	ORLANDO	FL	28-25-43.0220N	081-28-38.2590W	N
03408.*A	ORL	EXECUTIVE	ORLANDO	FL	28-32-43.7000N	081-19-58.5000W	Y
03406.11*H 37FA		FLORIDA HOSPITAL	ORLANDO	FL	28-34-32.0020N	081-22-06.2490W	N
03406.22*H FD36		FLORIDA HOSPITAL EAST ORLANDO	ORLANDO	FL	28-32-26.7000N	081-16-51.0000W	N
03406.40*H FL76		HELI-PARTNERS I-DRIVE	ORLANDO	FL	27-23-04.0000N	081-29-07.0000W	N
03406.39*H 97FD		HELICOPTERS INTL	ORLANDO	FL	28-27-51.8300N	081-27-35.8800W	N
03407.2*A	ISM	KISSIMMEE GATEWAY	ORLANDO	FL	28-17-23.3000N	081-26-13.5000W	Y
03406.*C	91FL	LAKE CONWAY NORTH	ORLANDO	FL	28-28-45.0140N	081-22-03.2510W	N
03406.33*C 89FL		LAKE HIAWASSEE	ORLANDO	FL	28-31-45.0100N	081-28-51.2600W	N
03407.15*A 54FD		LM-ETS	ORLANDO	FL	28-22-03.0000N	081-04-34.0000W	N
03407.09*H 82FD		LOCKHEED MARTIN	ORLANDO	FL	28-26-48.4900N	081-27-03.6900W	N
03406.18*H 32FL		MEYER	ORLANDO	FL	28-30-05.0120N	081-26-39.2560W	N
03408.4*H	27FA	ORANGE COUNTY SHERIFF’S OFFICE	ORLANDO	FL	28-30-27.0110N	081-24-48.2540W	N
03407.*A	MCO	ORLANDO INTL	ORLANDO	FL	28-25-45.8000N	081-18-32.4000W	Y
03406.21*H FD28		ORLANDO RGNL MEDICAL CENTER	ORLANDO	FL	28-31-31.0090N	081-22-37.2510W	N
03407.1*A	SFB	ORLANDO SANFORD INTL	ORLANDO	FL	28-46-37.1000N	081-14-05.7000W	Y
03406.29*H 7FA5		PREMIUM	ORLANDO	FL	28-23-21.0000N	081-29-19.0000W	N
03406.113*H 26FA		PRINCETON HOSPITAL	ORLANDO	FL	28-34-06.0040N	081-26-02.2550W	N
03406.14*A 01FA		RYBOLT RANCH	ORLANDO	FL	28-35-21.9970N	081-08-39.2290W	N
03406.38*C 12FL		TIMBERLACHEN	ORLANDO	FL	28-35-34.0000N	081-24-14.0000W	N
03406.34*H 0FL7		WKMG-TV	ORLANDO	FL	28-35-38.7000N	081-25-11.6000W	N
03406.3*H	13FD	YELVINGTON	ORLANDO	FL	28-31-07.0090N	081-22-59.2520W	N

• Required Functions

void printData(airPdata airport);

Description: Prints the data for a given airport, using the same format as the provided header line.

Input: A pointer to an airPdata structure.

Special Cases: If a NULL pointer is passed to this function, print an error message to STDERR and return from the function without printing anything to STDOUT.

Returns: Nothing

• Testing

There are several possible approaches for parsing the input data. Regardless of the approach you use, make sure to test your code on Eustis even if it works perfectly on your machine . If your code does not compile on Eustis you will receive a 0 for the assignment. There will be four (4) files provided for testing your code, they are as follows.

	Table 2: Test Files
Filename	Description
twolines.csv	Two lines of test data, where one
	line consists of lower case letters, one
	unique letter per field, the other line
	will consist of uppercase letters.
orlando5.csv	Five lines of Orlando airport data.
orlando.csv	All 26 of the Orlando airports.
florida.csv	All 877 of Florida’s airports.

The expected output for these test cases will also be provided. To compare your output to the expected output you will first need to redirect STDOUT to a text file. Run your code with the following command (substitute the actual name of the input CSV file):

./etl inputFile > output.txt

The run the following command (substitute the actual name of the expected output file):

diff output.txt expectedOutputFile

If there are any differences the relevant lines will be displayed (note that even a single extra space will cause a difference to be detected). If nothing is displayed, then congratulations the outputs match! For each of the four (4) test cases, your code will need to output to STDOUT text that is identical to the corresponding expectedOutputFile. If your code crashes for a particular test case, you will not get credit for that case.

• Grading

Scoring will be based on the following rubric:

	Table 3: Grading Rubric
Deduction	Description
-100	Code does not compile on Eustis
-100	Code does not accept the input file-
	name from the command line
– 15	Code does not show an error message
	and/or does not exit safely when there
	is a file I/O problem
– 20	crashed on twolines.csv, or output does
	not match
– 20	crashed on orlando5.csv, or output does
	not match
– 20	crashed on orlando.csv, or output does
	not match
– 20	crashed on florida.csv, or output does
	not match
– 5	Missing the academic honesty affirma-
	tion (See Submission Instructions)

• Submission Instructions

The assignment shall be submitted via WebCourses. There should only be one file in the submission.

The main source file named hw1etl.c (The submitted file should be all lowercase, but to capitalized version is printed here to avoid any spelling errors from misreading the filename: HW1ETL.C. Again, your filename should be all lowercase.)

The header file airPdata.h should not be submitted. The graders will already have it. Do not rely on a modified copy of airPdata.h, and do not hard code the airPdata structure in your main source file. Doing so will cause your code to not compile.

Include a comment at the top of your main source file that contains the following statement (substitute your name and NID) – “I [name] ([NID]) affirm that this program is entirely my own work and that I have neither developed my code together with any another person, nor copied any code from any other person, nor permitted my code to be copied or otherwise used by any other person, nor have I copied, modified, or otherwise used program code that I have found in any external source, including but not limited to, online sources. I acknowledge that any violation of the above terms will be treated as academic dishonesty.”

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