CSCI 2134代写、代做program语言程序、Python程序调试

日期：2021-01-29 11:42

CSCI 2134 Lab 1: Using Git

Winter 2021

Objective

In this lab, you will apply your knowledge of version control, notably Git, to manage a set of files

for a project. You will be given a Git repository of a project and will be asked to perform several

changes to the files in the project.

Aside: The code in question comes from a sequence of assignments that students were assigned

in CSCI 3136, which involved writing an interpreter for a small language. This lab is intended to

be a simulation of these assignments. You will be given all the intermediate source files and will

be adding them to the project as if you were writing it yourself. That is, the following lab represents

the set of steps students would need to do to store and manage their assignments in Git.

Preparation

It is STRONGLY recommended that you complete Task 1 of Assignment 1 prior to this lab.

Ensure that your CSID is active and you can log into your GitLab account at

https://git.cs.dal.ca.

If not, please see instructions in Assignment 1 to accomplish this. All work will be done in the CS

GitLab server. Do not use an external Git service like GitHub.

Ensure that you have read and understood the material on version control and Git from the

course. You might also gain some insights through an online Git tutorial, like the one at

https://try.github.io.

Resources

Support files: https://git.cs.dal.ca/courses/2021-winter/csci-2134/lab1/lab1-support-files.git

Procedure

Set-up

1. Open a command-line window (Terminal on a Mac or gitbash on Windows)

2. Create the directory where you would like to store a local copy of Lab 1. e.g.,

mkdir git/csci2134/lab_1

The above assumes that you have already created a git directory in your home directory

and a csci2134 directory inside the git directory.

3. Change directories to where you would like to store a local copy of Assignment 1, e.g.,

cd git/csci2134/lab_1

4. Clone the repository for lab 1 supporting files repository, which you will need for the lab.

Use the following command and Git URL:

git clone https://git.cs.dal.ca/courses/2021-winter/csci-2134/lab1/lab1-support-files.git

A directory called lab1-support-files will be created. Ensure that it contains the following

subdirectories, each with files in them:

v1 splatlex.py

v2 splatparse.py

v3 splat.py splateval.py

v4 splat.py splatred.py

v5 splat.py splatlambda.py

v6 splat.py splatselect.py

v7 splat.py splatuard.py

5. Clone the repository for your lab 1 using the following command and Git URL

git clone https://git.cs.dal.ca/courses/2021-winter/csci-2134/lab1/????.git

where ???? is your CSID. A directory with the same name as your CSID will be created,

containing Lab 1 code.

6. Change directories into the cloned lab 1 repository, where ???? is your CSID.

cd ????

Part 1: Accessing the History of a Project

7. Checkout (switch to) a branch called incremental:

git checkout incremental

You will see a directory called incremental, which will contain a file called splat.py.

8. Check to ensure you are on the right branch

git status

You will should see a message of the form

On branch incremental

nothing to commit, working tree clean

You should use git status regularly to confirm the branch and files you are working on.

9. Create a temporary text file outside of the local repository (e.g., on your Desktop) to record

answers to the following questions:

a. How many versions of splat.py have been committed on this branch? Use the command

git log to view all commits and the following command to view just all commits of

the specific file

git log -- incremental/splat.py

b. For each of the commits, what was the date and the commit comment?

c. Which class was added to splat.py before the current version? Use the command:

git diff HEAD^ -- incremental/splat.py

Note: HEAD refers to the tip of the branch; HEAD^ refers to the previous commit, and

HEAD^^ refers to the commit before that, etc.

d. How many lines of code was the first commit of incremental/splat.py (scanner)?

Hint: to move to a previous commit you can use the command

git checkout HEAD^

Repeating this command will move you to the preceding commit. The command

git checkout incremental

returns you to the tip of branch. To count the number of lines, simply load the file into

an editor.

10. Return to the main branch

git checkout main

Notice that the incremental directory has vanished and that a file called answers.txt

has appeared in the lab 1 directory. Use git status to confirm that you are on the

main branch.

11. Record the answers to the questions in the answers.txt file. Record also your name

and banner number to make the marker’s life easier.

12. Prepare to commit the changes you made to answers.txt. This is called staging:

git add -A

13. Check to ensure that the file has been staged

git status

The modified files should be listed.

14. Commit the changes

git commit -m “Added answers to Part 1 of the lab”

Note: the -m switch allows you to specify a commit comment on the command line. If it is

not provided, an editor will be invoked for you to add a commit comment.

15. Push the changes back up to the repository

git push origin main

Part 2: Basic Operations

Whenever we make changes to a code-base, the recommended procedure is to (i) branch the

code-base, (ii) make the changes in the branch, merge the branch back into the main branch

once you are satisfied with them. Hence, the motto: “branch often and commit early”. For the

second part of the lab we will do this a few times to practice our skills. Note: that the first time

we commit in a repository, we can commit on the main branch.

16. Create a src subdirectory in the lab 1 directory (same location as answers.txt):

mkdir src

17. Copy the files from the lab1-support-file/v1 to src

18. Add (Stage), check status, commit, and push the changes, like in steps 12 – 15

The rest of the lab involves simulating the development of the code:

19. Create a branch from the main branch called development:

git branch development

20. Switch to the development branch, similar to steps 7 – 8

21. Copy the files from the lab1-support-file/v2 to src.

22. Add and commit the changes, with a suitable commit message

23. Repeat steps 21 and 22 with the files in v3, v4, v5, v6, and v7 directories. If you were doing

this over the span of several days, step 23 would also be done for each version, ensuring

your code is backed up on a remote server.

24. Push the development branch to the repository

git push -u origin development

Having finished (and presumably tested) the code, we now merge it back to the main branch

25. Switch to the main branch (like in step 10)

26. Merge the development branch into the main branch

git merge development

27. Push the main branch to the repository (like in step 15)

28. Log in to the git web interface and check that your files were added, committed and pushed

successfully: https://git.cs.dal.ca/courses/2021-winter/csci-2134/lab1/????.git

29. You’re done!

Grading

The lab will be marked out of 4 points:

Task 2 Points 1 Point 0 Points

Task

1

All questions are answered

in answers.txt. Answers

are mostly correct.

The file answers.txt

has been modified and

contains some answers.

The file answers.txt

has not been modified,

Task

2

The commit and merge history

is mostly correct.

Some of the commits and

merges have been done.

No evidence of any commits

or merges.