git
Signing work
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 git log:
$ git log --show-signature -1
You can configure git log to check any signatures and list them in output via %G? 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
Making a pull request
1. Fork the project
2. Clone your fork
$ git clone git@gitrepo.com:mhan/forkedproject.git
3. Set up environment to keep fork updated
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
4. Make updates of your own
Create a new branch before making any changes
$ git checkout master
$ git branch newfeature
$ git checkout newfeature
5. Submit a pull request
Rebase your development branch against upstream master branch.
$ git fetch upstream
$ git checkout master
$ git merge upstream/master
$ git checkout newfeature
$ git rebase master
Squash multiple commits into fewer commits
$ git checkout
$ git rebase -i master
Submit
- After pushing to the forked project, select development branch and click the pull request button.
Accepting and merging a pull request
Commands
Add
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
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'
$ git rebase master
First, rewinding head to replay your work on top of it...
Applying: added Greeter class
Applying: hello uses Greeter
Applying: updated Rakefile
$
Start a new branch
$ git checkout -b newbranch
Switched to a new branch 'newbranch'
Merge a branch
$ git checkout autonotif
Switched to branch 'autonotif'
$ git merge <branchname>
Merge made by the 'recursive' strategy.
foobarrecords_savenew.hns | 1 +
1 file changed, 1 insertion(+)
create mode 100644 foobarrecords_savenew.hns
Merges <branchname> onto autonotif branch
Rename a branch
and update in the remote as well
$ git checkout <old_name>
$ git branch -m <new_name>
$ git push origin --delete <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.
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
assume-unchanged
$ 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
email = mhan@pfg.fjfj.com
[core]
editor = vim
autocrlf = input
safecrlf = true
[color]
ui = always
[alias]
co = checkout
ci = commit
st = status
br = branch
df = difftool
hist = log --pretty=tformat:\"%C(yellow)%h %C(green)%ad %Creset| %s%C(red)%d %C(bold blue)[%an]\" --graph --date=short
hist2 = log --graph --abbrev-commit --decorate --date=relative --format=tformat:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(bold blue)\" --graph --date=short
histall = log --pretty=tformat:\"%C(yellow)%h %C(green)%ad %Creset| %s%C(red)%d %C(blue)[%an]\" --graph --date=short --all
hist10 = !git log --pretty=tformat:\"%C(yellow)%h %C(green)%ad %Creset| %s%C(red)%d %C(blue)[%an]\" --graph --date=short | head -n 10
hist10all = !git log --pretty=tformat:\"%C(yellow)%h %C(green)%ad %Creset| %s%C(red)%d %C(blue)[%an]\" --graph --date=short --all | head -n 10
listnames = diff-tree --no-commit-id --name-status -r
type = cat-file -t
dump = cat-file -p
ignore = update-index --assume-unchanged
track = update-index --no-assume-unchanged
ignorelist = !git ls-files -v | grep -s ^'h ' | cut -b 1-2 --complement[diff]
tool = vimdiff
[difftool]
prompt = false
[merge]
defaultToUpstream = true
Links
- http://longair.net/blog/2009/04/16/git-fetch-and-merge/
- a warning against pull
'http://git-scm.com/book/en/Git-Branching-Basic-Branching-and-Merging