What is Git?

Version control tool: used to manage our modification history of files and directories in the development process, convenient to view historical records, for easy viewing.

The main difference between Git and SVN

The SVN is a centralized version control tool, and the version library is centralized on the central server. The first thing to do is download it from a central server.

Git is a distributed version control management system. There is no central server. Everyone’s computer is a complete version library, and you only need to submit your own changes.

advantages

  • Suitable for distributed development with emphasis on individuals.
  • Public server pressure and data volume are not too high.
  • Fast and flexible.
  • Conflicts between any two developers can be easily resolved.
  • Work offline.

Git Theoretical Basis

The working area

  • Working Directory -Working Directory
  • The staging area – Stage
  • Repository – the Repository
  • Remote Git repository -Remote Directory

The working process

1. Add and modify files in the working directory;

2. Put the files that need to be versioned into the temporary storage area;

3. Commit the files in the staging area to git repository.

Git operation

To manage project root execution

Create a working directory with common instructions

Get Git repository

Create a new warehouse

git init // Create a new Git code base in the current directory
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Clone remote repository

$git clone [url]Copy the code

git pull & git fetch

Git fetch pulls the latest content from the remote host to the local branch, which the user checks and decides whether to merge to the local branch

Git pull pulls down and merges the latest content of the remote host directly. git pull = git fetch + git merge

  • git fetch

    • Git fetch Remote host address Git fetch Remote host address branch // FETCH_HEAD // Check the latest host status based on the FETCH_HEAD. - Determine whether to update git merge FETCH_HEAD // Merge the latest drop into the codeCopy the code

  • git pull

    • Git pull Remote host name Branch nameCopy the code

Submit the commit

GIT file manipulation

When Git commits, the main concern is whether the file has changed between two versions. The way to determine whether the file has changed as a whole is to calculate the checksum of the file using sha-1.

Four states of a file

  • Untracked: in a folder but not added to a Git library, not involved in version control — Git add.
  • Unmodify: The file is stored but not modified.
  • No other operations have been performed, Git Add has entered Staged, and Git checkout has been discarded
  • Staged: Staged, execute git commit to synchronize changes into the library.

Viewing file Status

git status
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Add files and directories

Add files to the staging area

Git add. // all [filename]Copy the code

Example Remove files and directories

git rm --cached <file>
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View the differences between modified files

git diff [files]
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Git diff --cached git diff --cachedCopy the code

Ignore files

.gitignore

A set of rules

Submit the commit

Commit files from the staging area to the local repository

$git commit [file1] [file2] $git commit [file2] $git commit -v $git commit -v $git commit -v $git commit -- amend-m [message] # amend the last commit, $git commit --amend [file1] [file2]...Copy the code

View the Commit Log

git log

View logs of all branches

“Git reflog” records all updates to all branches of the repository, including those that have been undone.

Viewing the File List

git ls-files

Undo the local warehouse update

git reset –hard

A rollback operation

Git reverses the rollback operation.

  • In the workspace
Git checkout -- git checkout --Copy the code
  • (Add, not commit)
Git reset HEAD. // All git reset HEAD filesCopy the code

  • (Committed, not pushed)

    Git reset --head <commitID>// go back to the last commitCopy the code

  • (push)

git revert head
git push origin master

git reset --hard HEAD^
git push origin master -f
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revert & reset

  • Revert: Drops a specified change, but generates a new commit
  • Reset: Points the head pointer to the specified commit. It will not be found in history.

Reset has three modes: Hard Mixed soft

Hard: Both native source and native uncommitted source fall back to a version

–soft: retain the source code, commit the information is rolled back to a certain version, and does not change locally

— Mixed: Keep the source code, but revert git commit and index information to a version.

Git branch

$git branch -r $git branch -r $git branch [branch-name] $git checkout -b [branch] Commit $git branch [branch] [commit] $git branch --track [branch] [remote-branch] $git checkout [branch-name] $git checkout - $git branch --set-upstream [branch] [remote-branch] $git merge [branch] $git cherry-pick [commit] $git branch -d [branch-name] # $git push origin --delete [branch-name] $ git branch -dr [remote/branch]Copy the code

Git merges branch code into the master branch

Git pull: Get code remotely and merge local versions

First switch to the current branch

git checkout noworigin
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Use Git pull to pull down the branch code

git pull
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Switch to the main branch

git checkout master
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Merge the branch code into the main branch

git merge noworigin 
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Push up

git push
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Tips: Other code merges the same way!