Quickies for git

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Hacks

• Adding a tag [permalink]
  Adding a tag in git:

  % git tag '0.1-demo' -m "Proof of concept demo for initial App47 distribution"
  

  Adds the tag, with the given comment.

  To push the tag up to github (or wherever)

  % git push --tags
  

• Deleting a remote git branch [permalink]
  Say you had a branch name "protocol-play" that's been pushed up to github. To remove it locally you do the usual git branch -D protocol-play (the capital D if you don't care about the merged status). You might need to git push. too.

  It's gone locally, but still exists up on github. Nuke it there with:

  % git push origin :protocol-play
  

• Diff added changes [permalink]
  You did a git add to stage a change, but now you want to see what that was. Use

  % git diff --cached
  

• Git Logging Options [permalink]
  git log [options] [--] [path]
  • -p — show the diff (patch)
  • -# — limit output (e.g. -23 to last 23 entries)
  • --since / --until — commits more recent (or older) than given date
  • --stat — abbreviated stats (adds/deletes, modified files)
  • --pretty=thing — Make output pretty. Things include oneline, short, medium, full, fuller, (no fullest), email, raw, format:, tformat: . use tformat if you want a newline at the end of the log
  • --graph — draw those funky git branch gtaphs
  • --author / --committer — filter on specific dude / dudette
  • --grep — filter on keywords in commit messages
  • --all-match — Turn multiple predicates from OR into AND

  Format Options

  • %H / %h — hash (shortened)
  • %T / %t — tree hash (shortened)
  • %P / %p — parent hash (shortened)
  • %an / %ae / %ad / %ar — Author name, email, date (relative)
  • %cd / %ce / %cd / %cr — Committer name, email, date (relative)
  • %n — newline

  Date format can be specific (1961-01-13), or relative ("4 years 23 months"). Can replace spaces with dots: 4.years.23.months. The actual format is undocumented (OF COURSE), but you can look at the approxidate code.

• Git rollback [permalink]
  Commit something (before pushing), and regret it?

  % git reset --soft "HEAD~1"
  

• Making a new remote branch [permalink]
  Say you cloned something from github, and you're wanting to make your own branch, and have it out on github land for off-site pushes

  git branch markd-dev
  git push -u origin markd-dev
  

• Moving a git tag to another revision. [permalink]
  github releases are based on tags. Sometimes when polishing a release you want to point it to a new tag. This is what I've used before:

  % git tag -d release-cg-pt3
  % git push origin :refs/tags/release-cg-pt3
  % git status
  % git tag release-cg-pt3 7f05a3de66
  % git push origin master --tags
  

  And the go to your github release page. It should say that the release has become a draft (due to the tag change). Edit it and republish it.

• Moving a tag [permalink]
  To move an existing git tag to the current version in your working tree:

  % git tag --force '0.1-demo' -m "pithy comment"
  
  And if you're using github or something
  
  % git push --tags
  

• Password-less github gitting [permalink]
  Typing in your username and password for github is annoying. You'll need to do the ssh key dance. instructions here.

  If your current checkout is via https (you can figure that out by doing git config -l (ell) and looking at the remote.origin.url). If it's https it's not going to use your ssh keys. You'll need to change it.

  If it was originally:

  remote.origin.url=https://github.com/someuser/GroovyProject.git

  You'd do:

  % git config remote.origin.url git@github.com:someuser/GroovyProject.git

• Pruning branches [permalink]
  After a while, stale branches can pile up, especially if you're pulling and pushing to a busy repo. Get rid of them locally with:

  % git remote prune --dry-run origin
  

  To see what'll get removed, and then

  % git remote prune origin
  

  To clean things out.

• Pushing only default branch by default [permalink]
  By default git push tries to push all the branches, sometimes eliciting this wonderful response:

  error: failed to push some refs to 'git@github.com:bignerdranch/roominant.git'
  hint: Updates were rejected because a pushed branch tip is behind its remote
  hint: counterpart. If you did not intend to push that branch, you may want to
  hint: specify branches to push or set the 'push.default' configuration
  hint: variable to 'current' or 'upstream' to push only the current branch.
  hint: you might as well just give up. neener neener neener.  love, Git
  

  So you can tell git to only push the currently active branch:

  % git config --global push.default current

• Three faces of git diff [permalink]
  git diff shows changes made since the file was last staged. If you make changes, stage them, then make more changes, this only shows you the more changes

  git diff --staged shows changes made to the file when it was staged, diffs against the committed version it's based off of. It doesn't include any changes you've made since staging.

  git diff HEAD (where HEAD is the name of a commit - HEAD to compare with the latest commit, or a branch name to compare to the tip of that branch. In essence, unions git diff and git diff HEAD

• Undo the last commit [permalink]
  Accidentally added one too many files to the last commit (or some similar travesty). If you haven't pushed it up to github or somewhere else, you can roll it back with

  git reset --soft HEAD~1

• git "revert" [permalink]
  To remove uncommitted changes so you can pull without complaint (revert in svn-speak):

  % git checkout  filename-to-revert
  

  This checks the file out from HEAD, removing the local modificaiton. (put -- before the file name in case you have a branch named the same as the file)

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