Description
Background: This lab requires performing some computation after reading from a file and writing the
results to a file. The files should be:
1. Path to input file is specified as first command-line argument (i.e., argv[1])
2. Path to output file is specified as second command-line argument (i.e., argv[2])
3. Use std::ifstream and std::ofstream to read and write text file(s)
Procedure: Modify the supplied starter code lab3.cpp
(https://miamioh.instructure.com/courses/129645/files/17445388/download?wrap=1)
(https://miamioh.instructure.com/courses/129645/files/17445388/download?download_frd=1) using the
following steps:
1. Add the necessary variables to main function to enable use of command-line arguments [2 points]
2. Add an if-check to ensure that the user has specified exactly 2 command-line arguments (i.e.,
properly check argc’s count fo both the input and output file paths). [4 points]
If not, report the following error: “Specify input and output files” and return 0
3. Open input and output file streams using command-line arguments argv[1] and argv[2] [4 points]
Ensure the streams were created successfully using the good method
Example: myFile.good() returns true if the stream is created successfully
If the streams are not good, report an error “Error opening input or output streams” and return
from main with value of 0
NOTE: You must name your output file stream output to ensure your code will compile
5. Determine the proper data structure and properly declare/initialize it. [3 points]
6. Properly process the input file store the contents of it into that data structure from step 5. [5 points]
7. Modify the methods to functions to take in some parameter and perform a computation [3 points] for
each method
8. Write the results of the computations to an output file with the specified output [8 points]:
Sum: [sum]
Min: [min]
Average: [average]
Max: [max]
NOTE: the brackets [] represent the actual numerical value (i.e., it should print something like “Sum:
31”’’)
The code must pass the style guidelines [2 points]
NOTE: typically, we would not return 0 for the failure case as this suggested a successful run. However,
the CODE plugin will correctly consider it a failed test if there is a return larger then 0 (this would be a
failed execution). Since the goal is to assess error handling, this is not really a traditional test failure and
so we are returning 0.
Input File for Testing:
The file lab3_input.txt (https://miamioh.instructure.com/courses/129645/files/17056116/download?wrap=1)
(https://miamioh.instructure.com/courses/129645/files/17056116/download?download_frd=1) contains a
sample input to test your program.
Functional Testing in the Terminal: Functional testing is the process of checking to ensure that a
program is operating correctly – i.e., generates the expected output for a given input. Functional testing
is accomplished by comparing the output from a program against a known or expected output. The
CODE plugin performs this for you when you submit. However, we can also do this testing directly in the
terminal with the following steps:
1. Download the lab3_expected_output.txt
(https://miamioh.instructure.com/courses/129645/files/17445389/download?wrap=1)
(https://miamioh.instructure.com/courses/129645/files/17445389/download?download_frd=1) file and
move it to the directory where your lab3 program is
2. Open the terminal and navigate to your lab3 program if you are not there already
3. Run your program with the sample input file lab3_input.txt
(https://miamioh.instructure.com/courses/129645/files/17056116/download?wrap=1)
(https://miamioh.instructure.com/courses/129645/files/17056116/download?download_frd=1) and writing
output to a file lab3_output.txt with the following command:
./lab3 lab3_input.txt lab3_output.txt
4. Now, we can compare our results with the expected results using diff (this is the same tool used in
the CODE plugin):
Lab 3 Rubric
diff lab3_output.txt lab3_expected_output.txt
5. If your program is operating correctly, then the above diff command will generate zero differences –
i.e., it will produce absolutely no output
Total Points: 40
Criteria Ratings Pts
2 pts
4 pts
4 pts
3 pts
5 pts
12 pts
8 pts
2 pts
Add the necessary variables to main function to enable use of command-line
arguments
2 pts
Full
Marks
0 pts
No
Marks
Add an if-check to ensure that the user has specified exactly 2 command-line
arguments (i.e., properly check argc’s count fo both the input and output file
paths).
4 pts
Full
Marks
0 pts
No
Marks
Open input and output file streams using command-line arguments argv[1] and
argv[2]
4 pts
Full
Marks
0 pts
No
Marks
Determine the proper data structure and properly declare/initialize it. 3 pts
Full
Marks
0 pts
No
Marks
Properly process the input file store the contents of it into that data structure from
step 5.
5 pts
Full
Marks
0 pts
No
Marks
Modify the methods to functions to take in some parameter and perform a
computation for each method
12 pts
Full
Marks
0 pts
No
Marks
Write the results of the computations to an output file with the specified output 8 pts
Full
Marks
0 pts
No
Marks
Style guidelines 2 pts
Full
Marks
0 pts
No
Marks
