# create a new branch checkouted from current commit, and switch to the new branch
$ git checkout -b <new_branch_name>

# create a new branch checkouted based on a specific reference (branch, remote/branch, tag are examples of valid references)
$ git checkout -b <new_branch_name> <reference>
# e.g.,
$ git checkout -b feature-branch master

# Create new branch based on the current commit (but doesn't switch to the new branch created)
$ git branch <branch_name>

# Create new branch based on a specific commit
$ git branch <branch_name> <commit_hash>

# Checkout to a specific existing local branch
$ git checkout <branch_name>

# Switch to the previously checked out branch
$ git checkout -

# Switch to an existing remote branch
$ git checkout --track <remote_name/branch_name>

# List local branches. The current branch is highlighted by *
$ git branch

# List all branches (local and remote):
$ git branch -a

# List all remote branches
$ git branch -r
$ git branch -r | grep <...>

# 查看本地分支及追踪的分支
$ git branch -vv

# Delete a local branch. The branch must be fully merged in its upstream branch
$ git branch -d <branch_name>

# Forcefully delete a local branch
$ git branch -D <branch_name>

# Delete a remote branch
$ git push <remote_name> --delete <remote_branch_name>
# e.g.,
$ git push origin --delete <remote_branch_name>

# Rename a local branch
$ git branch -m [old branch name] [new branch name]

# Add a remote repository
$ git remote add origin ssh://git@github.com/[username]/[repository-name].git

# [most useful] - Merge a branch into current branch and create a merge commit
$ git merge --no-ff <branch_name>

# Merge a branch into your current branch
$ git merge <branch_name>

# Edit the merge message
$ git merge -e <branch_name>

# Merge a branch into a target branch
$ git merge <source branch> <target branch>

# Abort a merge in case of conflicts
$ git merge --abort

# Rebase the current branch on top of another specified branch:
$ git rebase new_base_branch

# Abort a rebase in progress (e.g. if it is interrupted by a merge conflict):
$ git rebase --abort

# If do merge
$ git log
commit 4f00d87afb943e7f6dcd996cdecd5400a7455d8e (HEAD -> feature2)
Merge: deb6375 d63e8ae
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:04:40 2021 +0800

    Merge branch 'master' into feature2

commit d63e8ae391d5f0be3f93752779e6f0e9a93be140 (origin/master, origin/HEAD, master)
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:03:53 2021 +0800

    add master 2

commit deb6375401ce5ed08a6e7c4e492ef800fc98f497 (origin/feature2)
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:03:17 2021 +0800

    add 1 feature2

commit 66bac5735e15ab56ab305e5f49daa68850024740
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:02:21 2021 +0800

    add master -1

commit e9994724f709b903c4ccce2f5252ddb4ed561d91
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 22:53:54 2021 +0800

    add 4
    
    
# If do rebase
$ git log
commit bc7bfd015b81df9023df8f3b18aad89ff7ca1cd9 (HEAD -> feature2)
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:03:17 2021 +0800

    add 1 feature2

commit d63e8ae391d5f0be3f93752779e6f0e9a93be140 (origin/master, origin/HEAD, master)
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:03:53 2021 +0800

    add master 2

commit 66bac5735e15ab56ab305e5f49daa68850024740
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 23:02:21 2021 +0800

    add master -1

commit e9994724f709b903c4ccce2f5252ddb4ed561d91
Author: Shi Wei <wei.shi@xx.com>
Date:   Fri Jun 25 22:53:54 2021 +0800

    add 4

# Preview changes before merging
$ git diff [source branch] [target branch]

git diff main new_branch ./diff_test.txt

# Fetch the latest changes from the default remote upstream repository (if set)
$ git fetch

# Fetch new branches from a specific remote upstream repository
$ git fetch <remote_name>

# Fetch the latest changes from all remote upstream repositories
$ git fetch --all

# Also fetch tags from the remote upstream repository
$ git fetch --tags

# Send local changes in the current branch to its remote counterpart
$ git push

# Publish tags that aren't yet in the remote repository
$ git push --tags

# Download changes from default remote repository and merge it:
$ git pull

# Download changes from default remote repository and use fast forward:
$ git pull --rebase

# Download changes from given remote repository and branch, then merge them into HEAD:
# e.g., `git pull origin master` and then need to checkout to master branch by `git checkout master`
$ git pull <remote_name> <branch>

$ git show <commit_SHA>

# e.g.,
$ git show d63e8ae391d5f0be3f93752779e6f0e9a93be140
commit d63e8ae391d5f0be3f93752779e6f0e9a93be140 (origin/master, origin/HEAD, master)
Author: Shi Wei <wei.shi@aa.com>
Date:   Fri Jun 25 23:03:53 2021 +0800

    add master 2

diff --git a/spss_profile.sh b/spss_profile.sh
index f18e41a..8d06e08 100755
--- a/spss_profile.sh
+++ b/spss_profile.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 1 - master
-2
+2 - master
 3
 4
 # Usage

# -L
# The -L option will restrict the output to the requested line range. Here we have restricted the output to lines 1 through 5.
git blame -L 1,5 README.md

# Commit staged files to the repository with a message
$ git commit -m <message>

# Auto stage all modified files and commit with a message
$ git commit -a -m <message>

# Replace the last commit with currently staged changes:
$ git commit --amend

# Commit only specific (already staged) files:
$ git commit <path/to/my/file1> <path/to/my/file2>

$ git revert f5dec261b1183c8e39d7db34844df424e8cd8971
[master e6ca3ae] Revert "add a commit"
 1 file changed, 1 insertion(+), 1 deletion(-)

$ git revert -n <commit's SHA-1>

$ git revert @

$ git checkout <commit-B-SHA>

# If you want to create a new branch to retain commits you create, you may do so (now or later) by using -c with the switch command.
$ git switch -c <new-branch-name>
  
# Or undo this operation with
$ git switch -

# Reset the repository to a given commit, with discarding committed, staged and uncommitted changes since this given commit
$ git reset --hard <commit SHA>

# Apply a commit to the current branch
$ git cherry-pick commit

# To list local branches containing commit:
$ git branch --contains <commit-id>

# List all branches, including remote only, containing commit:
$ git branch -a --contains <commit-id>

$ if [ 0 -eq $(git merge-base --is-ancestor $COMMIT_ID HEAD) ]; then echo "true"; else echo "false"; fi

# or
$ git log | grep <commit_id>

          ┌───┐      ┌───┐     ┌───┐      ┌───┐
    ...   │ A │◄─────┤ B │◄────┤ C │◄─────┤ D │
          └───┘      └───┘     └───┘      └───┘

 After Squashing commits B, C, and D:

          ┌───┐      ┌───┐
    ...   │ A │◄─────┤ E │
          └───┘      └───┘

          ( The commit E includes the changes in B, C, and D.)

git reset --soft HEAD~3 &&
git commit

# If
pick d94e78 Prepare the workbench for feature Z     --- older commit
pick 4e9baa Cool implementation 
pick afb581 Fix this and that  
pick 643d0e Code cleanup
pick 87871a I'm ready! 
pick 0c3317 Whoops, not yet... 
pick 871adf OK, feature Z is fully implemented      --- newer commit

$ git rebase --interactive [commit-hash]
pick d94e78 Prepare the workbench for feature Z     --- older commit
s 4e9baa Cool implementation 
s afb581 Fix this and that  
s 643d0e Code cleanup
s 87871a I'm ready! 
s 0c3317 Whoops, not yet... 
s 871adf OK, feature Z is fully implemented      --- newer commit

# Show changed files which are not yet added for commit, but which are tracked already:
$ git status

# Add a file to the index
$ git add <path/to/file>

# Only add already tracked files:
$ git add -u

# Add a file to the index
$ git add <path/to/file>

$ touch pool.go
$ vim pool.go
$ git status
On branch release
Your branch is up to date with 'origin/release'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	pool.go

nothing added to commit but untracked files present (use "git add" to track)

$ git add .
$ git status
On branch release
Your branch is up to date with 'origin/release'.

Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
	modified:   container/tester.go
	new file:   pool.go

# Add all files (tracked and untracked)
$ git add -A

# Also add ignored files
$ git add -f

# Unstage all staged files (to unstaged mode, but still keep them)
$ git restore --staged :/

# Unstage everything but keep the changes
$ git reset

# Discard unstaged files
$ git restore path/to/file

# Discard all unstaged changes to tracked files (in the current directory)
$ git restore .
# Discard all unstaged changes to tracked files (in the working tree)
$ git restore :/

# Restore an unstaged file to the version of a specific commit
$ git restore --source commit <path/to/file>

# Discard all unstaged changes in the current directory
$ git checkout .

# Discard unstaged changes to a given file
$ git checkout <filename>

# Discard staged files
$ git restore --staged <file>...

# Discard all changes to files, both staged and unstaged
$ git restore --worktree --staged :/

# discard everything
$ git reset --hard

# Dry-run to see what untracked files will be deleted (will not display the unstaged changes in tracked files)
$ git clean -n -d
Would remove pool.go

# After you are sure
$ git clean -f -d
Removing pool.go

# Interactively delete files that are not tracked by git:
$ git clean -id

# Forcefully and recusively delete directories/files that are not tracked by git:
$ git clean -fd

$ git status
On branch release
Your branch is up to date with 'origin/release'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	pool.go

nothing added to commit but untracked files present (use "git add" to track)
# Dry-runly remove both files ignored by Git and files untracked
$ git clean -dn -x
Would remove .idea/
Would remove log/
Would remove pool.go
# Dry-runly remove only files ignored by Git
$ git clean -dn -X
Would remove .idea/
Would remove log/

# Stash current changes
$ git stash

# Stash current changes, including new (untracked) files
$ git stash -u

# Apply a stash (default is the latest, named stash@{0})
$ git stash apply [<optional_stash_name_or_commit>]

# lists all stashed changesets
$ git stash list 

# do some code change
$ git stash
$ git pull
$ git stash apply

# Replace a file in the current directory with the version of it committed in a given branch
$ git checkout <branch_name> -- <filename>