Written August 25, 2022 • Last edited August 29, 2022
Link to the assignment on Canvas, where you will submit your single .tar file.
tar -cvf lab1_X.tar FuelX.cpp
Due by 11:59pm Tuesday, September 6, 2022
If you want to skip directly to the lab notes, click here.
I highly recommend you stay up to date with Piazza, but here I will reiterate the most important bits of the lab submission guidelines and the slides since they are very important and this should be like at least your third time seeing this:
Please pay attention to both the names of your tar file and the source code files inside—it's case-sensitive. It makes grading easier, so we would appreciate it very much :)
Save copies of your completed versions as FilenameX.cpp so that you don't accidentally overwrite something and lose all of your work. It also ensures you have something to turn in if you've ruined your latest version to the point that it doesn't compile.
WARNING: If your code does not compile on the Hydra machines using g++, it will be a zero if we cannot immediately see the issue. It is your responsibility to make sure of this before your final submission!
If you have a concern about your most recent lab submission or your grade, make a private Piazza post to "Instructors" about it.
Late policy:
Don't cheat. (please)
There are a few options for accessing a suitable Unix-like environment on your machine, which ideally should be the only place you try to compile and run code, especially in courses later on and in life. My first semester, I tried doing a COSC 130 (230 now?) assignment on Windows and got a bug that took a whole group of TAs to figure out: whatever the bug was, it was because the size of a long on Windows is only 32 bits—the same as an int. Stupid, right? (Though there is a reason).
Anyway, some options are better than others, but you can decide what you like best. If you've taken classes here before and/or you're already using Linux, you probably don't need to read this section.
Note: The step of testing on Hydra should not be disregarded, no matter what.
If you have any questions or need help setting something up, don't hesitate to reach out to me or one of the other TAs or come to office hours.
Note: I say VSCode here because I recommend it and don't even know what else people actually use, but use whatever editor you prefer.
scp to Hydra for compilation and testingThis is the simplest option no matter what OS you have, and unless you kind of know what you're doing, I'd stay away from Option 2. There is a summary of scp in the next major section. If you are on Mac, I think you can still develop, compile, and test your code locally without weird bugs, but you should still test your code on Hydra before submitting.
scp to Hydra for final compilation and testingI've never heard of any instructors at UTK recommending this, but I think it's pretty good and should catch on.
WSL (Windows Subsystem for Linux) is basically Microsoft's official solution to the lack of a terminal with Unix commands. I've used WSL for the last year, and I wish I had known about it earlier. This one is nice because you might find it to be useful for other classes and projects too.
I don't remember running into any issues when I did it, so I think this part should be straightforward. Just follow these instructions.
Note: I will not take any responsibility for anything that happens if you try this and mess something up! If at any point you don't understand what the documentation is saying, you might want to stop there.
VSCode also has an extension for WSL integration, so you can directly edit the file in VSCode.
I also recommend trying to set up Windows Terminal to open the WSL terminal, and it's nice in general, but this is not required. Microsoft also has some instructions for additional recommended stuff, including Windows Terminal.
By default, you can start a WSL shell using the wsl command and compile and test there.
WARNING: While it might be nice to have everything all in one place, you should still
scpyour tar file to Hydra to test your code JUST TO BE SURE!
Arguably the worst one, but if you want to become a god at Vim like Dr. Plank or you like to suffer, you can do this. However, this is actually good for quick edits so you can compile and test again without scp, but for the bulk of the coding, I recommend one of the previous options. However, be sure to scp the code back or make the changes locally before you tar and submit.
As you might have noticed, for convenience, I'll provide you with a skeleton command you might use to create your tar file at the top of each one of these pages, but you should understand how to use all of these commands on your own.
Note: Access the current directory or its parent directory using
.and.., respectively.
ls lists files in current directory or optional provided directory.
ls [(optional) directory]
cd changes current directory to provided directory.
cd [directory]
mv moves or renames a file to the destination path.
WARNING: This will overwrite any files in the destination with the same name.
mv [source] [destination]
Examples:
Moves test1 into directory cs302:
mv test1 cs302/test1
or
mv test1 cs302
Renames test1 to test2 (if test2 is not an existing directory):
mv test1 test2
mkdir creates a directory (-p creates parent directories as needed).
mkdir [directory name]
Example: (in the current directory, creates folder test1, containing test2, containing test3)
mkdir -p test1/test2/test3
cat ("concatenate") at its core simply views the contents of a file. There's a lot more you can do with it, but know this for now.
cat [file]
chmod ("change mode") updates the read/write/execute permissions on a file or directory. Read more on the octal number here, but you need to know 700 makes your file private.
chmod [octal permissions] [file or directory]
Example: (makes cs302 directory private)
chmod 700 cs302
ssh is used to securely remotely access a system, such as the Hydra machines.
ssh [netid]@hydra[X].eecs.utk.edu
Example:
ssh broachel@hydra5.eecs.utk.edu
scp is used to securely copy files between a local and remote source/destination.
WARNING: This will overwrite any files in the destination with the same name.
scp [source] [destination]
Examples: (assuming you are in the local directory where your files are / where you want your files to be)
Note: These commands are run on your local machine.
Copy source code from your local machine to where you want it on Hydra:
scp FuelX.cpp broachel@hydra5.eecs.utk.edu:~/cs302/Lab1/
Copy source code from Hydra to your local machine:
scp broachel@hydra5.eecs.utk.edu:~/cs302/Lab1/FuelX.cpp .
To copy entire directories, you can use scp -r ("r" for recursive)—this will overwrite the directory's contents if names are the same:
scp -r Lab1 broachel@hydra5.eecs.utk.edu:~/cs302/
tar is used to compress one or more files into a single file. If you're curious about the flags or want more info.
See the lab submission guidelines for a more complete set of notes, but here are some simple examples.
WARNING: The next two commands will overwrite any files in the current directory with the same name. Similar to
g++ -o, make sure the arguments are in the correct order.
Create a tar file named tar_file_name.tar containing files file1, file2, ..., fileN:
tar -cvf [tar_file_name.tar] [file1 file2 ... fileN]
Extract contents of a tar file:
tar -xvf [tar_file_name.tar]
Check contents of a tar file:
tar -tf [tar_file_name.tar]
There are four parts to this lab. Submit a tar file containing only the highest completed part.
Note: These are mainly Andrew's notes from the slides, but I've copied and adapted them here with some extra stuff. THIS IS NOT A REPLACEMENT FOR THE LAB WRITEUP—NOT ALL THE DETAILS ARE HERE. Use this as only a reference.
struct sale: Holds information about each input line (objects of this type are stored in the vector DB)
int for month, day, and yearenum for fuel typedouble for quantity, unit price, and subtotalstruct sale {
int year;
int month;
int day;
fuel_type type;
double quantity;
double unit_price;
double subtotal;
};
overloaded input operator (>>): Takes each line and parses the data to create the struct for that sale
sscanf(), something like string date;
istreamParameterVariableName >> date;
sscanf(date.c_str(), "%02d-%02d-%4d", &month, &day, &year);
overloaded output operator (<<): Formats the output of the sale struct
printf() as it will round the decimal numbers when printing—write to the ostream & with <<, left, right, and setw() insteadint month and enum fuel_type // A similar application of this concept
const char *alphabet_str[] = {
"apple", "banana", "c++", ..., "zebra"
};
// Remember: characters are numbers too
for(char c = 'a'; c <= 'z'; c++) {
// c-'a' efficiently maps each character to an index 0 - 26
// Think about the offset needed to align the first value with 0
cout << c << " is for " << alphabet_str[c-'a'] << endl;
}
./examplea is for apple
b is for banana
c is for c++
...
z is for zebra
return types for input/output stream overloads are istream & and ostream &, respectively
Example I/O (including output field widths and justifications):
08-01-2021 Midgrade 24.72 4.690
[date] [fuel type] [quantity] [unit price]
Aug 1, 2021 Midgrade 24.72 x 4.69 = 115.94 : 115.94
[month (3, left)] [day (2, right)], [year (4, right)] [fuel type (8, left)] [quantity (8, right)] x [unit price (4, right)] = [subtotal (7, right)] : [running total (9, right)]
Note: The width and justification of each section is important. While there is no penalty, if you can, make sure the output matches Dr. Gregor's / the test script's exactly using the provided information to make grading easier for us!
parse command-line arguments:
-inorder flag and the file name that we will extract data from-inorder maintains the order of the output as the order of the inputExample argv/argc:
./Fuel2 -inorder fuel_data1.txt
argv[0] argv[1] argv[2] argc = 3
print_details():
DB), and prints out the dataYour output should be exactly the same as Fuel1 because your output doesn't change, only how you read in and call your output changes in your code
-inorder (maintains input order) (./Fuel3 -inorder fuel_data2.txt)-bydate (sorted by date of sale) (./Fuel3 -bydate fuel_data2.txt)-bytype (sorted by fuel type) (./Fuel3 -bytype fuel_data2.txt)-bydate and -bytypestd::sort()sale_summary:double member variables+= operator (takes in a sale object)<< again with the following field widths[quantity (10, right)] x [unit price (4, right)] = [subtotal (8, right)]
print_summary_bydate()print_summary_bytype()sale_summary objects and attempt to add each object's data to a map. Upon failure of insertion to the map, update the value pointed to by the returned iterator with the current struct's datastd::map insert() --> returns a pair<iterator, bool>print_summary_bytype():insert() will return trueinsert() will return false, so you will update the struct already inserted before as the iterator in the pair will be referencing that structsale_summary struct that is initialized with a sale structI have provided a test script. For those who have had professors who provided a gradescript, this script is not giving you a grade. This is just a way to help automate testing. Please utilize it.
RUN THIS SCRIPT ON THE SCHOOL MACHINES! I had problems developing it on Windows, so just run it on the school machines for consistency!
First un-tar the script in the directory you have set up.
The script will look for a specific file format: Fuel#.cpp, where # is the latest version you are working on.
The script fails to run on compile and runtime errors.
Your script output on tests that are marked incorrect are in the scriptDir/ given from the tar file. Look for the corresponding number to see your output difference.
Your difference files for output that differs from the solution will be in scriptDir/ listed as diff#.txt, where # is the corresponding failed test case. The solution output will be on the right side of that file.
The output format needs to match the solution output format. If you notice that the output lines are the same content-wise but it lists as incorrect, your formatting is incorrect somewhere. Below are the field widths for output for Parts 1-3:
For Part 4, you have different field widths for the -summary flag.
If you have -bytype -summary:
For -bydate -summary:
If you are having problems, feel free to reach out and we can help you!
std::mapEven if you think you're already familiar enough with C++ maps, I encourage you to give this a read-through anyway—you might still learn something. It was written by former TA Clara Nguyen, known for being one of the best CS TAs ever.
Also, in general, I encourage you to pay attention to the return value of data structure operations (such as insert() above). While C++'s std::stack doesn't have this, usually stacks are implemented such that when you call pop(), the popped element is returned. Stuff like that. You never know what useful info you might be missing, and it might come in handy during a job interview.