intro to git

Question 1

what is system comands

Answer 1

Ls/pwd/cd

Question 2

what is git and git repo

Answer 2

git is version control system for software development.
git repo is directory containing files and sub directory represented in .git file

Question 3

commands for creating new rep / for convert an existing repo

Answer 3

1- git init repo_name
2- cd repo_name
3- git status

1- cd to the directory and use git init then track it by using git status

Question 4

what is git workflow commands?

Answer 4

1- Add files to staging area using:
git add file_name
git add . -> for adding all changes even in sub directory

2- commit the file (git take a snapshot of the file) using:
git commit -m “message”

Question 5

what is the commit structure?

Answer 5

1- commit: contain author, log message and commit time
2- tree: track the name and location of files and directories in the repo
3- Blob: binary large object includes any data and its a compressed snapshot of files content
4- git hash: 40 digits unique pseudi random number generated by hash function, if 2 files has the same hash then they are the same

Question 6

what commands used to track the changes over such a file (5)?

Answer 6

git log show the hostory of commits for repo , used as:
1- git log
2- git log -x -> x in the number of commits
3- git log -x file_name
4- git log –since=”date’ –until=””
5- git show hash_no -> use 8 to 10 numbers only

Question 7

what is the comparing commands (6)?

Answer 7

using git diff:
1- git diff -> compare between all the unstaged and the latest commit
2- git diff file_name -> compare between commited and local (unstaged) version
3- git diff –staged file_name -> compare between the staged copy and the last commit
4- git diff –staged -> compare all staged files with the last commit
5- git diff hash_no_1 hash_no_2 -> compare between 2 commits by using their hash numbers
6- git diff HEAD~1 HEAD -> compare between last commit and last commit -1

Question 8

what is reverting and what is its main commands (3)?

Answer 8

• reverting in git is reverting the repo to the state before the last commit
• using: git revert HEAD or hash.
  entering the command open a text editor , use Ctrl+o then Enter for saving and Ctrl+x for exiting
• git revert –no-edit HEAD for not opening a text editor
• git revert -n HEAD for reverting without commiting

Question 9

what to use to revert a single file and why?

Answer 9

git checkout HEAD – file_name
because git revert works on commits not inividual files

Question 10

how to unstage a single file? all files?

Answer 10

• git restore –staged file_name
• file restore –staged