Git: Difference between revisions

Get your GPG configured, and a personal key installed.  Configure Git to use your personal key.

$ git config --global user.signingkey 0A46826A

=== Signing commits ===

You can sign commits simply by adding -S once your environment is configured.

$ git commit -S -m 'push a signed commit'

You can check and verify via <span class="package">git log</span>:

$ git log --show-signature -1

You can configure <span class="package">git log</span> to check any signatures and list them in output via <span class="package">%G?</span> format.

$ git log --pretty="format:%h %G? %aN  %s"

You can also reject commits that are unsigned and invalid:

$ git merge --verify-signature non-verify

$ git merge --verify-signatures signed-branch

Sign the merge commit itself:

$ git merge --verify-signatures -S signed-branch

== Workflows ==

2. Clone your fork

$ git clone git@gitrepo.com:mhan/forkedproject.git

Set up upstream remote:

$ git remote add upstream git@gitrepo.com:unmit/project.git

Update your fork:

$ git fetch upstream

$ git branch -va

$ git checkout master

$ git merge upstream/master

Create a new branch before making any changes

$ git checkout master

$ git branch newfeature

$ git checkout newfeature

Rebase your development branch against upstream master branch.

$ git fetch upstream

$ git checkout master

$ git checkout newfeature

$ git rebase master

Squash multiple commits into fewer commits

$ git checkout

$ git rebase -i master

Add only modified and deleted files:

$ git add -u

=== Tags ===

Signing tags:

$ git tag -s v2.17 -m 'version 2.17 signed by MH'

$ git show v2.17

With the signer's public key in the keyring, you can verify the tag:

$ git tag -v v2.17

Upload a specific tag:

$ git push origin v2.29.1

Upload all tags:

$ git push origin --tags

Remove a tag locally

$ git tag -d <tagname>

Remove a tag on the remote repo

$ git push --delete origin v0.1.8

Get the latest tag in the current branch

$ git describe --abbrev=0 --tags

* Reference: [https://www.xspdf.com/resolution/50066178.html#:~:text=Git%20get%20latest%20tag%20on%20current%20branch&text=To%20get%20the%20latest%20annotated,%2Dmatch%20%2D%2Dabbrev%3D0. Tag-related commands]

=== Clone a specific branch ===

$ git clone --depth 1 --single-branch -b 2.0.0 https://github.com/user/reponame.git

=== Get a build number ===

A commit count can be used as a build number for a revision (e.g. HEAD, master, a commit hash):

$ git rev-list --count <revision>

To get the commit count across all branches:

$ git rev-list --all --count

To get the number of commits without merges for develop branch:

$ git rev-list --no-merges --count develop

=== Add a local branch that tracks a remote branch ===

$ git branch --track greet origin/greet

$ git branch -a

$ git merge origin/master

=== Pulling changes from a remote ===

$ git fetch

$ git merge origin/master

is equivalent to:

$ git pull

=== Cleaning up remote branch list ===

This cleans up and removes any branches that are no longer on the remote

$ git remote prune origin

=== Rebase a branch ===

$ git checkout cbranch

Switched to branch 'cbranch'

$

=== Start a new branch ===

$ git checkout -b newbranch

Switched to a new branch 'newbranch'

=== Merge a branch ===

$ git checkout autonotif

Switched to branch 'autonotif'

  1 file changed, 1 insertion(+)

  create mode 100644 foobarrecords_savenew.hns

Merges <branchname> onto autonotif branch

and update in the remote as well

$ git checkout <old_name>

$ git push origin -u <new_name>

=== Delete a branch ===

* Delete a local branch

$ git branch -d hotpatch1

* Delete a remote branch

git push origin --delete hotpatch1

* Delete a remote branch that as no actual reference on the remote

git branch -r -d origin/hotpatch1

=== List merged branches ===

List branches merged into master

$ git branch --merged master

List branches merged into HEAD (i.e. tip of current branch)

$ git branch --merged

List branches that have not been merged

$ git branch --no-merged

=== Undo last commit ===

This undo is recorded as a part of the git log.

$ git revert HEAD

=== Fix or amend last commit ===

$ git commit --amend

=== Undo changes to a file ===

$ git checkout -- filename

=== Reset the branch to a specific point in the past ===

$ git reset --hard <hash>

--hard parameter also updates the working directory. Reset shouldn't be used in a group project on a remote repository because of its potential for confusion.

=== Reset the branch to a specific branch on a remote ===

$ git reset --hard origin/master

=== Ignore files ===

;Temporary ignore changes to a file

$ git update-index --assume-unchanged <filename>

;Back to tracking changes to the file

$ git update-index --no-assume-unchanged <filename>

;Get a list of folders and files that are <code>assume-unchanged</code>

$ git ls-files -v | grep '^h'

=== Ignore file modes ===

This is useful when working with multiple file systems.

$ git config core.filemode false

=== Maintenance command ===

Verify the connectivity and validity of the objects

$ git fsck --unreachable

Manage reflog information

$ git reflog expire --expire=0 --all

Pack unpacked objects in a repository

$ git repack -a -d -l

Prune all unreachable objects from the object database

$ git prune

Clean up unnecessary files and optimize the local repository

$ git gc --aggressive

== Useful git aliases ==

This is a snapshot of my ~/.gitconfig

[user]

         name = Michael Han

[merge]

         defaultToUpstream = true

== Quick Start Guide ==