That Conference: Git More Done

The final session I attended was presented by Keith Dahlby.

• Config
• git help config
• git config –l
• You have the system level configs, user configs, and repository level configs
• git config –e –global (will open up the global config in default text editor)
• configs are pretty similar to INI files
• core.editor = <path>
• diff.renames = false|true|copies
• difftool.prompt = true|false
• mergetool.prompt = true|false
• mergetool.keepBackup = true|false
• help.autocorrect = 0|N|-1
• log.date=default|relative|local|iso|rfc short
• aliasing
• wrap a git command + arguments
• git config alias.ds “diff –stat”
• git ds –> git diff –stat
• git ds dev –> git diff –stat dev
• wrap shell commands
• http://bit.ly/better-git-svn
• http://bit.ly/git-lg
• Named Commits
• SHA1
• or the unique initial substring (6 often sufficient)
• Symbolic references:
• branch (moves with commits)
• Tag (remains static)
• remote references
• Head = what’s checked out
• reference to a branch
• Arbitrary commit (detatched HEAD)
• on commit, no branch to update
• ORIG_HEAD = “undo” for big HEAD changes
• Saved before reset, merge, pull, etc.
• FETCH_HEAD = last fetched from remote
• git fetch <url> <branch>
• MERGE_HEAD = incoming merge heads
• Relatively naming commits
• suffixes
• ~ = parent; ~n = nth-generation grandparent
• ^=first parent; ^n = nth merge parent
• 3 commits ago = HEAD~3 = HEAD^^^
• @{n} = nth prior value for that ref
• Undo last commit = git reset HEAD@{1}
• git help revisions
• Local workflow
• Ridiculously cheap – use liberally
• Write SHA to file in refs/heads
• Branches to clean up
• git branch – merged
• Keep Master clean!
• New topic branch from master
• git checkout master –b topic
• Commit more than feels natural
• git stash
• Stash away work in progress
• Typical workflow
• git stash save “comment…”
• switch to fix and then switch back
• git stash pop
• git stash save –include-untracked
• git stash list
• git stash show –p stash@{1}
• git stash drop stash@{1}
• git stash branch
• Temporary Commits
• Advantage: WIP lives in branch
• commit, then git reset HEAD~ to go back
• Reset path in index to match commit:
• git reset commit  -- <paths>…
• Unstage:
• git reset HEAD – stateged-file.txt
• Reset HEAD reference to commit:
• git reset [—<mode>] commit
• Discard previous commit:
• git reset HEAD~
• soft reset = move HEAD; don’t reset index/work tree. Essentially an uncommit
• mixed mode = reset index but not work tree (default). Unstage
• hard mode = reset index and work tree (discard changes (ignores untracked files); VERY DESTRUCTIVE!!!
• git add –patch allows for overlapping changes that should be in different commits
• reformatting
• refactoring
• changing functionality
• Allow for “hunks” (sections of diff) to stage
• Key operations: y/n, a (all)/d (delete), s (split), e (edit)
• Also can be done on reset, checkout, and stash save
• Rewriting History
• Permanent when pushed
• Until then, pretend you were perfect
• git commit –amend (easiest way to change the last commit)
• alias.cia = commit –amend –C HEAD
• git cia –a –reset-author
• git cherry-pick
• apply changeset(s) elsewhere
• like to the wrong branch
• merge vs rebase
• think of it like shuffling a deck of cards (merging) vs cutting a deck (rebasing)
• rebasing are a replay of commits
• rebase –interactive allows for replay with modifications
• rebase –autosquash … use “fixup! <message>” and git will automatically combine a commit with one awhile ago
• config rebase.autosquash
• Fixing “oops”
• git reflog
• ls –r .git/logs
• HEAD, heads, remotes
• git reflog –all
• Finding bugs
• git bisect
• binary search through a commit space
• git bisect visualize = view = overview in gitk/log
• git bisect skip (current version can’t be tested)
• run my_script = automated bisect
• http://github.com/dahlbyk/Presentations
• http://github.com/dahlbyk/posh-git