w1d6-w1d7 (Git)

Question 1

How can all files of a certain type be added to a commit?

Answer 1

Use a wildcard:

git add ‘*.txt’

Question 2

What is the syntax to add a named repo?

Answer 2

git remote add repo_name repo_address

Question 3

What does the -u flag do in the following command:

git push -u origin master

Answer 3

Tells git to remember the parameters for the push command, so ‘git push’ will suffice in the future.

Question 4

What is the syntax to retrieve changes to a repo?

Answer 4

git pull reponame branchname

Question 5

What does the following command do:

git diff HEAD

Answer 5

Assesses the difference between local files and the latest commit.

Question 6

How can we assess the difference between staged files and the last commit?

Answer 6

git diff –staged

Question 7

What is the command to unstage a file?

Answer 7

git reset filepath/filename

Question 8

How can we revert a file to its state at the last commit?

Answer 8

git reset – filename

Question 9

Explain the following command:

git rm ‘*.txt’

Answer 9

Removes all .txt files in the repo from the desk and the staging area.

Question 10

What is the point of the -a flag in the git commit command?

Answer 10

Auto removes files that were removed from the disk but not the staging area when the next commit occurs.

Question 11

What is a VCS?

Answer 11

A version control system; keeps track of different versions of files/projects.

Question 12

What is a CVCS?

Answer 12

A centralized version control system; keeps track of files on a server which multiple users can access.

Question 13

What is a DVCS?

Answer 13

A distributed version control system; versions are stored on a databases, and a user copies the entire repo everytime they access the files; prevents a single point of failure by ensuring that versions are distributed to multiple locations.

Question 14

What makes Git so fast?

Answer 14

It stores all commits as a series of snapshots on the server, distributed to all local machines, so local machines have access the the entire repo and do not need to always go back up to the server.

Question 15

What is the point of the checksum used to identify commits?

Answer 15

The checksum is based on the contents and directory structure at that time, so it is impossible to alter a file without Git knowing it.

Question 16

What are the three sections of a Git project, and what are the differences between them?

Answer 16

The .git repository, where all commits are stored, the Staging Area, where files are added to when they are planned to be committed, and the Working Directory, which consists of files on the local machine.

Question 17

What are the three states of a file in Git?

Answer 17

It can be committed, meaning a snapshot of the file in its current state has been taken, it can be modified, which means it is different than its last snapshot and is not being tracked, and staged, meaning it is different from its last snapshot and has been added to be committed.

Question 18

What are the three ways for getting help for a git command?

Answer 18

$ git help
$ git –help
$ man git-

Question 19

What is the distinction between snapshots and differences? Which does Git use?

Answer 19

Differences store a list of files and the changes made to them over time; snapshots store the files in their entirety each time they are committed (a file with no changes can be given a pointer back to the last changed version of the file). Git uses snapshots.

Question 20

What does the ‘git clone’ command do, and how is it used?

Answer 20

It allows you to copy an existing Git repository in its entirety. The syntax is:

$git clone repo_address optional_directory_name

Question 21

What is the difference between a tracked and an untracked file?

Answer 21

A tracked file was included in the last snapshot; it can be unmodified, modified, or staged.

An untracked file was not included in the last snapshot and is not staged.

Question 22

What happens when you pass ‘$git status’ a directory as an argument?

Answer 22

All files in the directory will be tracked recursively.

Question 23

T/F: If you modify a file after running ‘$git add’ on the file, you will have to add it again.

Answer 23

T

Question 24

What is the flag added to the status command to produce a more succinct output?

Answer 24

$git status -s

Question 25

What is the .gitignore file, and how can it be used to ignore generated files?

Answer 25

It tells Git to completely ignore files that are either listed or match a wildcard. To ignore generated files, add the following to .gitignore:

*~

This tells Git to ignore files that end with a ~. Similarly, to tell Git to ignore files with a .o or .a extension:

*.[oa]

Question 26

What is some of the syntax for the .gitignore file?

Answer 26

# no .a files
*.a

# but do track lib.a, even though you're ignoring .a files above
!lib.a

# only ignore the root TODO file, not subdir/TODO
/TODO

# ignore all files in the build/ directory
build/

# ignore doc/notes.txt, but not doc/server/arch.txt
doc/*.txt

# ignore all .txt files in the doc/ directory and its subdirectories
doc/**/*.txt

Question 27

What does ‘git diff’ show?

Answer 27

Unstaged changes

Question 28

How can we see changes between staged files and the last commit?

Answer 28

$git diff –staged

Question 29

How can a file be removed from a file from the staging area but let it remain on the disk?

Answer 29

$git rm –cached filename

Question 30

How can the ‘git mv’ command be used?

Answer 30

To rename a file:

$git mv from_file to_file

Question 31

Explain the following command:

$git log -p -2

Answer 31

Shows the differences between commits for the last two commits.

Question 32

Explain the following command:

$git log –since=2.weeks

Answer 32

Show all commits from the past 2 weeks.

Question 33

What does the –amend option do in ‘git commit’

Answer 33

Runs a commit that replaces the previous commit altogether.

Question 34

How can you revert a specific file to its state at the time of the the last commit?

Answer 34

$git checkout – filename

Question 35

How do you unstage a file?

Answer 35

$git reset HEAD filename

Question 36

How can you list all of your remote repositories with their address and their alias?

Answer 36

$git remote -v

Question 37

How can you retrieve the contents of a remote and place them as branches in your repo?

Answer 37

$git fetch repo_url_or_alias

Question 38

What is the difference between fetch and pull?

Answer 38

Fetch pulls the repo branches but does not merge them; pull retrieves a the HEAD (current branch of the remote) branch and merges it.

Question 39

How can you inspect a remote?

Answer 39

$git remote show repo_name

Question 40

How can you rename the alias of a remote?

Answer 40

$git remote rename old_name new_name

Question 41

How can you alias a Git command?

Answer 41

$git config –global alias.alias_name old_name

Question 42

How can you set the authorship of commits on a local machine?

Answer 42

git config user.name “username”

git config user.email “email”

Question 43

How can you setup a remote that uses https when pushing?

Answer 43

https://github.com/your_username_here/repo_name.git

Question 44

How do we stage all files including new ones?

Answer 44

$git add -A

Question 45

How can we add an alias for a command to Bash?

Answer 45

Change ~/.bash_profile to include the line:

alias alias_name=’full command’