Git Reference

Move files from one repository to another, preserving git history

Source: https://medium.com/@ayushya/move-directory-from-one-repository-to-another-preserving-git-history-d210fa049d4b

Step 1: Getting files ready to move from Repository A (7 mini-steps)

Make a copy of repository A as the following steps make major changes to this copy which you should not push!

mkdir cloneA
cd cloneA
git clone --branch <branch> --origin origin --progress \
  -v <git repository A url>

# eg. git clone --branch master --origin origin --progress \
#   -v https://github.com/username/myproject.git

# (assuming myprojects is the repository you want to copy from)

Go to that directory.

cd <git repository A directory>

#  eg. cd myproject
# Folder Path is ~/cloneA/myproject

To avoid accidentally making any remote changes (eg. by pushing), delete the link to the original repository.

git remote rm origin

Go through your history and files, removing anything that is not in FOLDER_TO_KEEP. The result is the contents of FOLDER_TO_KEEP spewed out into the base of repository A.

git filter-branch --subdirectory-filter <directory> -- --all
# eg. git filter-branch --subdirectory-filter subfolder1/subfolder2/FOLDER_TO_KEEP -- --all

Clean the unwanted data.

git reset --hard
git gc --aggressive 
git prune
git clean -fd

Move all the files and directories to a NEW_FOLDER which you want to push to repository B.

mkdir <base directory>
#eg mkdir NEW_FOLDER

mv * <base directory>
#eg mv * NEW_FOLDER

Alternatively, you can drag all the files and directory to the NEW_FOLDER using GUI.

Add the changes and commit them.

git add .
git commit

Step 2: Merge the files into the new repository B

Make a copy of repository B if you don’t have one already.

mkdir cloneB
cd cloneB

git clone <git repository B url>
# eg. git clone 
https://github.com/username/newproject.git

Go to that directory.

cd <git repository B directory>
#  eg. cd newproject
# Folder Path is ~/cloneB/newproject

Create a remote connection to repository A as a branch in repository B.

git remote add repo-A <git repository A directory>
# (repo-A can be anything - it's just a random name)

# eg. git remote add repo-A ~/cloneA/myproject

Pull files and history from this branch (containing only the directory you want to move) into repository B.

git pull repo-A master --allow-unrelated-histories
# This merges master from repository A into repository B

Remove the remote connection to repository A.

git remote rm repo-A

Finally, push the changes

git push

You can delete both the cloned repositories.

The files changes with history are now available online in repository B.

Git Bash on Windows - using the `tree` command

Use cmd //c tree to use Windows’ tree in Git Bash

Writing Better Commit Messages

Source: https://medium.com/swlh/writing-better-commit-messages-9b0b6ff60c67

start commit message with clickup task number/JIRA ticket number

Templating Pull Requests & Merge Requests

Source: https://appi2393.medium.com/templating-pull-request-merge-request-b6e1f51a2994

Roll back Git code to previous commit

Source: https://www.techtarget.com/searchitoperations/answer/How-to-roll-back-Git-code-to-a-previous-commit

Fatal: Not possible to fast-forward, aborting

Source: https://stackoverflow.com/questions/13106179/fatal-not-possible-to-fast-forward-aborting

git pull --rebase You don’t need to know the name of your destination branch.

If your upstream branch is not set, try git pull origin <branch> --rebase

To set this option globally, use git config --global pull.rebase true

Gitlab: Connect commits to issues, MRs and snippets

In the commit message include:

To reference an issue: #ISSUE_ID
To reference a MR: !MR_ID
To reference a snippet: $SNIPPET_ID

Source: Tutorial: It’s all connected in GitLab

Gitlab Issue: Time Tracking

Aside: Quick Actions: Quick actions are text-based shortcuts for common actions that are usually done by selecting buttons or dropdowns in the GitLab user interface. You can enter these commands in the descriptions or comments of issues, epics, merge requests, and commits. Be sure to enter each quick action on a separate line to allow GitLab to properly detect and execute the commands. Source: https://docs.gitlab.com/ee/user/project/quick_actions.html

/estimate
/remove_estimate
/spend
/remove_time_spent

Eg. /spend 30m

You can view a breakdown of time spent on an issue or merge request.

To view a time tracking report:

Go to an issue or a merge request.
In the right sidebar, select Time tracking report.

Source: Time tracking

Git Issue: git forces refresh index after switching between windows and linux

Source: https://stackoverflow.com/questions/59061816/git-forces-refresh-index-after-switching-between-windows-and-linux

GitHub Profile Achievements

GitHub Profile Achievements 🏆

Gitlab SSH Setup and Clone

Use SSH keys to communicate with GitLab

Gitlab CI/CD

Squash several commits into a single a commit

How to enter command with password for git pull?

For http(s):

you can put the password in .netrc file (_netrc on windows). From there it would be picked up automatically. It would go to your home folder with 600 permissions.
you could also just clone the repo with https://user:pass@domain/repo but that’s not really recommended as it would show your user/pass in a lot of places…
a new option is to use the credential helper. Note that credentials would be stored in clear text in your local config using standard credential helper. credential-helper with wincred can be also used on windows.

Usage examples for credential helper

git config credential.helper store - stores the credentials indefinitely.
git config credential.helper 'cache --timeout=3600'- stores for 60 minutes

For ssh-based access, you’d use ssh agent that will provide the ssh key when needed. This would require generating keys on your computer, storing the public key on the remote server and adding the private key to relevant keystore.

Source:

How do I push a new local branch to a remote Git repository and track it too?

In Git 1.7.0 and later, you can checkout a new branch:

git checkout -b <branch>

Edit files, add and commit. Then push with the -u (short for --set-upstream) option:

git push -u origin <branch>

Git will set up the tracking information during the push.

Source: How do I push a new local branch to a remote Git repository and track it too?

Squash commits and merge on new branch

# create a new branch
git checkout -b new_clean_branch

# apply all changes
git merge original_messy_branch

# forget the commits but have the changes staged for commit
git reset --soft main        

git commit -m "Squashed changes from original_messy_branch"

Source: https://stackoverflow.com/questions/3133449/why-does-git-rebase-give-me-merge-conflicts-when-all-im-doing-is-squashing-comm

How do I delete a Git branch locally and remotely?

Executive Summary

$ git push -d <remote_name> <branchname>
$ git branch -d <branchname>

Note: In most cases, <remote_name> will be origin.

Delete Local Branch

To delete the local branch use one of the following:

$ git branch -d <branch_name>
$ git branch -D <branch_name>

The -d option is an alias for –delete, which only deletes the branch if it has already been fully merged in its upstream branch.
The -D option is an alias for –delete –force, which deletes the branch “irrespective of its merged status.” [Source: man git-branch]
As of Git v2.3, git branch -d (delete) learned to honor the -f (force) flag.
You will receive an error if you try to delete the currently selected branch.

Delete Remote Branch

As of Git v1.7.0, you can delete a remote branch using

$ git push <remote_name> --delete <branch_name>

which might be easier to remember than

$ git push <remote_name> :<branch_name>

which was added in Git v1.5.0 “to delete a remote branch or a tag.”

Starting with Git v2.8.0, you can also use git push with the -d option as an alias for –delete. Therefore, the version of Git you have installed will dictate whether you need to use the easier or harder syntax.

Source: https://stackoverflow.com/questions/2003505/how-do-i-delete-a-git-branch-locally-and-remotely

Pro Git Book

https://git-scm.com/book/en/v2

Git symlink - Symbolic Links

Good practice for creating symlink in Git

# Not good for Git repositories
ln -s /Users/gio/repo/foo.md ./bar/foo.md

# Good for Git repositories
cd ./bar && ln -s ../foo.md foo.md

The reason for this is that given that a symlink contains the path to the referenced file, if the path is relative to a specific machine the link won’t work on others. If it’s relative to the repository itself on the other hand, the OS will always be able to find the source.

Reference

https://mokacoding.com/blog/symliks-in-git/
https://github.com/mokacoding/symlinks

Source: https://stackoverflow.com/questions/56504821/sharing-git-repo-symlinks-between-windows-and-wsl

Resetting, Checking Out & Reverting

Source: https://www.atlassian.com/git/tutorials/resetting-checking-out-and-reverting

Check data type in NumPy

Source: https://www.geeksforgeeks.org/check-data-type-in-numpy/

git fetch vs git pull

git pull = git fetch + git merge

Git Fetch is the command that tells the local repository that there are changes available in the remote repository without bringing the changes into the local repository. Git Pull on the other hand brings the copy of the remote directory changes into the local repository.

Source: https://www.geeksforgeeks.org/git-difference-between-git-fetch-and-git-pull/

How do I revert a Git repository to a previous commit?

Source: https://stackoverflow.com/questions/4114095/how-do-i-revert-a-git-repository-to-a-previous-commit

Git Detached Head: What This Means and How to Recover

Source: https://www.cloudbees.com/blog/git-detached-head

Compare two git branches - git diff

Source:

https://devconnected.com/how-to-compare-two-git-branches/
https://www.junosnotes.com/git/how-to-compare-two-git-branches/
https://stackoverflow.com/questions/4099742/how-to-compare-files-from-two-different-branches

Three Git Configurations that Should Be the Default

git config --global pull.rebase true
git config --global fetch.prune true
git config --global diff.colorMoved zebra

Source: https://spin.atomicobject.com/2020/05/05/git-configurations-default/

How can I remove an entry in global configuration with git config?

You can remove the core.excludesfile setting like this:

git config --global --unset core.excludesfile

And of course you can simply edit the config file:

git config --global --edit

and then remove the setting by hand.

Source: https://stackoverflow.com/questions/11868447/how-can-i-remove-an-entry-in-global-configuration-with-git-config

How can I see the changes in a Git commit?

To see the diff for a particular COMMIT hash, where COMMIT is the hash of the commit:

git diff COMMIT~ COMMIT will show you the difference between that COMMIT’s ancestor and the COMMIT. See the man pages for git diff for details about the command and gitrevisions about the ~ notation and its friends.

Alternatively, git show COMMIT will do something very similar. (The commit’s data, including its diff - but not for merge commits.) See the git show manpage.

(also git diff COMMIT will show you the difference between that COMMIT and the head.)

Source: https://stackoverflow.com/questions/17563726/how-can-i-see-the-changes-in-a-git-commit

gitexplorer

Find the right commands you need without digging through the web.

Source: https://gitexplorer.com/

Git rebase your branch on top of main and force-push

https://docs.gitlab.com/ee/topics/git/git_rebase.html

git checkout main
git pull
git checkout <your-branch>
git rebase main
git push --force origin <your-branch>

Better commit messages

https://www.freecodecamp.org/news/how-to-write-better-git-commit-messages/

Gitlab - transfer existing project into new namespace for the group

https://about.gitlab.com/blog/2014/06/30/feature-highlight-groups/#:~:text=Transferring%20an%20existing%20project%20into,new%20namespace%20for%20the%20group

How to Undo a Git Add

To undo git add before a commit, run git reset <file> or git reset to unstage all changes.

Delete local branch

https://www.git-tower.com/learn/git/faq/delete-local-branch

How to reset, revert, and return to previous states in Git

https://opensource.com/article/18/6/git-reset-revert-rebase-commands

What’s the difference between git reflog and log?

git log shows the current HEAD and its ancestry. That is, it prints the commit HEAD points to, then its parent, its parent, and so on. It traverses back through the repo’s ancestry, by recursively looking up each commit’s parent.

(In practice, some commits have more than one parent. To see a more representative log, use a command like git log –oneline –graph –decorate.)

git reflog doesn’t traverse HEAD’s ancestry at all. The reflog is an ordered list of the commits that HEAD has pointed to: it’s undo history for your repo. The reflog isn’t part of the repo itself (it’s stored separately to the commits themselves) and isn’t included in pushes, fetches or clones; it’s purely local.

Aside: understanding the reflog means you can’t really lose data from your repo once it’s been committed. If you accidentally reset to an older commit, or rebase wrongly, or any other operation that visually “removes” commits, you can use the reflog to see where you were before and git reset –hard back to that ref to restore your previous state. Remember, refs imply not just the commit but the entire history behind it.

Source: https://stackoverflow.com/questions/17857723/whats-the-difference-between-git-reflog-and-log

Git - Mental models and Cheatsheet

https://dsinecos.github.io/blog/Git-basics

Rebase — One of the Most Powerful Git Commands

https://medium.com/osedea/git-rebase-powerful-command-507bbac4a234

How Git works under the hood?

https://medium.com/@siavash.sajjady/how-git-works-under-the-hood-d3dbdfafca75

How to permanently remove few commits from remote branch

You git reset --hard <COMMIT_ID> your local branch to remove changes from working tree and index, and you git push --force

https://stackoverflow.com/questions/3293531/how-to-permanently-remove-few-commits-from-remote-branch

Rewriting History

https://git-scm.com/book/en/v2/Git-Tools-Rewriting-History

Discard all changes and pull from upstream

git reset --hard origin/master
git pull origin master

https://stackoverflow.com/questions/13781388/git-discard-all-changes-and-pull-from-upstream

Delete a branch locally and remote

// delete branch locally
git branch -d localBranchName

// delete branch remotely
git push origin --delete remoteBranchName

Automatic prune with Git fetch or pull

git config --global fetch.prune true

https://stackoverflow.com/questions/18308535/automatic-prune-with-git-fetch-or-pull

How do I check out a remote Git branch?

git fetch origin

This will fetch all of the remote branches for you. You can see the branches available for checkout with:

git branch -v -a

With the remote branches in hand, you now need to check out the branch you are interested in with -c to create a new local branch:

git switch -c test origin/test

For more information about using git switch:

man git-switch

https://stackoverflow.com/questions/1783405/how-do-i-check-out-a-remote-git-branch

Convert line-endings for whole directory tree (Git)

find . -type f -exec dos2unix {} \;

https://stackoverflow.com/questions/7068179/convert-line-endings-for-whole-directory-tree-git/7068241#7068241

Discard all local changes

git reset –-hard

VSCode not showing changes in source control git panel

Restart the extension host by Command palette (Ctrl + Shift + P) -> Restart Extension Host. Then, create a file by running touch aaa.txt. Git now shows all changed files. Delete aaa.txt

Source: https://stackoverflow.com/questions/58467720/vscode-not-showing-changes-in-source-control-git-panel