Git

Here's a good crash course for subversion users.

Hosting

• GitHub provides pretty reasonable git hosting services; open source projects eat free.
• github-trac is a trac extension for working with GitHub
• Remote repacks/compressions can consume a great deal of memory. To cap the remote packing at, say, 2G, enter the remote repository and run:

git config pack.windowMemory 1000m
git config pack.packSizeLimit 2000m

Configuration

Dump your user configuration with git config -l:

[recombinator](129) $ git config -l
user.name=Nick Black
user.email=dank@qemfd.net
github.user=dankamongmen
[recombinator](0) $

Dump the system configuration, if one exists, via git config --system -l:

[recombinator](129) $ git config --system -l
color.diff=auto
color.status=auto
color.branch=auto
[recombinator](0) $

Subversion equivs

goal	subversion	git
Add an external repository repo at point dir/path	svn propedit svn:externals dir, and add repo path	git submodule add repo dir/path (there's a Submodule Tutorial)

Recipes

Create bare repo from existing files

We have existing, untracked files at workpath. We want to initialize a (possibly remote) bare repository repo with the contents of workpath.

• In repo/, run git init --bare
• In workpath/, run git init
• In workpath/, run git remote add origin repo
• In workpath/, run git add .
• In workpath/, run git push

Prune remote branches

git remote prune origin

This can be made automatic with git config remote.origin.prune true since git 1.8.5.

Hard sync to upstream

Warning: this will throw away even committed local changes! Assuming remote upstream and branch master:

git reset --hard upstream/master

then, to force your own fork to match:

git push origin master --force

Congratulations! You've just thrown away any local work.

Remove local+remote tag

• git tag -d TAG
• git push --delete origin TAG

Rename local+remote branch

Remote branches cannot be renamed in a single step. Instead,

• Check out the remote branch if it is not checked out
• Rename the local branch with git branch -m newname
• Delete the remote branch with git push origin ––delete oldname
• Re-add and reset the remote branch with git push origin –u newname

Find commit corresponding to tag

• git rev-list -n 1 TAG

List all commits between two hashes Ce and Cb

• git rev-list Ce..Cb

Update local list of remote branches

• git remote update origin --prune

Change base branch BBase of branch Bbranch to BNewbase

• git rebase --onto BNewbase BBase Bbranch

Show changes in commit C, even if it's a merge commit

• git show --diff-merges=on C

See also

• GitHub

Links

• Tv's "Git for Computer Scientists"
• tpope's "Note About Git Commit Messages" (2008-04-19)
• GitWiki's GitTips